• Absolute Calibration Standards

    Silicon photodiodes are used as calibration standards in the extreme ultraviolet (EUV) region due to their stability and radiation hardness.

    Silicon photodiodes are used as calibration standards in the extreme ultraviolet (EUV) region due to their stability and radiation hardness.

  • Absolute Detectors

    Devices calibrated to provide precise measurements of radiation intensity. Used in applications like deep-ultraviolet lithography and excimer laser dosimetry.

    Devices calibrated to provide precise measurements of radiation intensity. Used in applications like deep-ultraviolet lithography and excimer laser dosimetry.

  • Absolute Intensity Measurement

    Measurements requiring precise calibration and stable detector response, essential in applications like synchrotron radiation and plasma diagnostics.

    Measurements requiring precise calibration and stable detector response, essential in applications like synchrotron radiation and plasma diagnostics.

  • Absolute UV Silicon Photodiodes (AXUV)

    Photodiodes designed to detect photons with energy greater than 1.12 eV, achieving near theoretical quantum efficiency due to the absence of surface dead regions and their thin silicon dioxide protective window.

    Photodiodes designed to detect photons with energy greater than 1.12 eV, achieving near theoretical quantum efficiency due to the absence of surface dead regions and their thin silicon dioxide protective window.

    Related: AXUV photodiodes from Opto Diode.

  • Accelerated Testing

    A testing methodology to evaluate long-term stability under extreme conditions. UVG photodiodes exhibited less than 1% change in responsivity after exposure to high humidity, UV radiation, and elevated temperatures.

    A testing methodology to evaluate long-term stability under extreme conditions. UVG photodiodes exhibited less than 1% change in responsivity after exposure to high humidity, UV radiation, and elevated temperatures.

    Related: UVG photodiodes from Opto Diode.

  • Active Area

    The region of a photodiode that is sensitive to light and contributes to the generation of photocurrent.

    The region of a photodiode that is sensitive to light and contributes to the generation of photocurrent.

  • Active Area Contamination

    The active area of EUV photodiodes must not be touched, sneezed on, or contaminated. Contaminants can only be cleaned gently using a clean room swab with electronic-grade acetone or alcohol.

    The active area of EUV photodiodes must not be touched, sneezed on, or contaminated. Contaminants can only be cleaned gently using a clean room swab with electronic-grade acetone or alcohol.

  • Active Collection Region

    The part of the silicon layer where photons or particles generate electron-hole pairs, contributing to the device’s current.

    The part of the silicon layer where photons or particles generate electron-hole pairs, contributing to the device's current.

  • Active Silicon Layer

    The silicon region in solid-state detectors where incident radiation generates electron-hole pairs, crucial for device sensitivity.

    The silicon region in solid-state detectors where incident radiation generates electron-hole pairs, crucial for device sensitivity.

  • Advanced Light Source (ALS)

    A facility used for performing calibrations and metrology on photodiodes, contributing to their development and testing in high-energy environments.

    A facility used for performing calibrations and metrology on photodiodes, contributing to their development and testing in high-energy environments.

  • Aluminum Gallium Arsenide (AlGaAs)

    A semiconductor material used in LEDs emitting in the deep red to near-infrared (IR) range (660nm – 900nm). Common applications include IR remote controls, night vision illumination, and industrial photocontrols.

    A semiconductor material used in LEDs emitting in the deep red to near-infrared (IR) range (660nm - 900nm). Common applications include IR remote controls, night vision illumination, and industrial photocontrols.

    Related: IR emitters and LEDs from Opto Diode.

  • Aluminum Indium Gallium Phosphide (AlInGaP)

    A semiconductor material used in LEDs emitting yellow-green to red light (565nm – 645nm). Frequently used in traffic signals and RGB white light systems.

    A semiconductor material used in LEDs emitting yellow-green to red light (565nm - 645nm). Frequently used in traffic signals and RGB white light systems.

    Related: IR emitters and LEDs from Opto Diode.

  • Amber LEDs (580nm – 590nm)

    Commonly used in amber traffic signal lights and RGBA white lights for enhanced color rendering.

    Commonly used in amber traffic signal lights and RGBA white lights for enhanced color rendering.

    Related: IR emitters and LEDs from Opto Diode.

  • Ambient Gas Operation

    EUV photodiodes can operate in ambient gases like helium, argon, and nitrogen, or under vacuum conditions lower than 10⁻¹⁰ torr.

    EUV photodiodes can operate in ambient gases like helium, argon, and nitrogen, or under vacuum conditions lower than 10⁻¹⁰ torr.

  • Angle of Incidence

    The angle at which radiation strikes the photodiode or a multilayer coating. Performance varies with angles, as seen in polarization studies of multilayer-coated photodiodes.

    The angle at which radiation strikes the photodiode or a multilayer coating. Performance varies with angles, as seen in polarization studies of multilayer-coated photodiodes.

  • Angular Dependence

    The variation in a photodiode’s responsivity or performance based on the angle of incoming radiation.

    The variation in a photodiode's responsivity or performance based on the angle of incoming radiation.

  • Application for Pulsed Laser Profiles

    Detectors can be used for pulsed laser profiles or positioning as long as the pulse width is within the detector’s response time, wavelength range, and power density limits.

    Detectors can be used for pulsed laser profiles or positioning as long as the pulse width is within the detector's response time, wavelength range, and power density limits.

  • Avalanche Photodiode (APD)

    A highly sensitive photodiode that operates with high reverse bias, leading to avalanche multiplication of photocurrent for enhanced detection of low-level light signals.

    A highly sensitive photodiode that operates with high reverse bias, leading to avalanche multiplication of photocurrent for enhanced detection of low-level light signals.

    Related: avalanche photodiodes from Opto Diode.

  • AXUV Electron Detectors

    Specialized silicon photodiodes optimized for detecting electrons and low-energy ions with near 100% internal quantum efficiency.

    Specialized silicon photodiodes optimized for detecting electrons and low-energy ions with near 100% internal quantum efficiency.

    Related: AXUV photodiodes from Opto Diode.

  • AXUV Photodiodes

    Reference to related photodiodes designed for detecting extreme ultraviolet (XUV) radiation with high stability.

    Reference to related photodiodes designed for detecting extreme ultraviolet (XUV) radiation with high stability.

    Related: AXUV photodiodes from Opto Diode.

  • Background Temperature (TB)

    The effective temperature of all radiation sources, exclusive of the chosen system source or target, in the detector field of view.

    The effective temperature of all radiation sources, exclusive of the chosen system source or target, in the detector field of view.

  • Backscattering Losses (ΔB)

    Losses in responsivity caused by electrons being reflected back from the front surface of the photodiode.

    Losses in responsivity caused by electrons being reflected back from the front surface of the photodiode.

  • Baking Test

    UVG photodiodes maintained stability after being baked at 100°C for four weeks, demonstrating their durability under prolonged heat exposure.

    UVG photodiodes maintained stability after being baked at 100°C for four weeks, demonstrating their durability under prolonged heat exposure.

    Related: UVG photodiodes from Opto Diode.

  • Bandgap Energy

    The energy required to excite an electron from the valence band to the conduction band in silicon, influencing the photodiode’s spectral response.

    The energy required to excite an electron from the valence band to the conduction band in silicon, influencing the photodiode's spectral response.

  • Bandpass

    The range of wavelengths transmitted by a photodiode’s multilayer coating. Specific bandpasses (e.g., 17–150 Å) are achieved by designing coatings with specific layer materials and thicknesses.

    The range of wavelengths transmitted by a photodiode's multilayer coating. Specific bandpasses (e.g., 17–150 Å) are achieved by designing coatings with specific layer materials and thicknesses.

  • Bandpass Filters

    Thin-film coatings applied to photodiodes to restrict sensitivity to specific wavelength ranges, such as 0.1–80 nm for EUV applications.

    Thin-film coatings applied to photodiodes to restrict sensitivity to specific wavelength ranges, such as 0.1–80 nm for EUV applications.

  • Bandpass Response

    The wavelength range over which a photodiode exhibits high sensitivity. Metal-coated photodiodes can be designed for specific bandpasses, such as the H Lyman alpha line.

    The wavelength range over which a photodiode exhibits high sensitivity. Metal-coated photodiodes can be designed for specific bandpasses, such as the H Lyman alpha line.

  • Bias Circuit Recommendations

    Use a voltage divider bias circuit with a load resistor set at either 1 MΩ or matched to the dark resistance of the detector. An FET input op-amp with high input impedance (~10¹² Ω) is recommended.

    Use a voltage divider bias circuit with a load resistor set at either 1 MΩ or matched to the dark resistance of the detector. An FET input op-amp with high input impedance (~10¹² Ω) is recommended.

  • Bias Voltage

    The applied voltage to a detector circuit, typically in DC volts.

    The applied voltage to a detector circuit, typically in DC volts.

  • Bias Voltage (VB)

    The external voltage applied to a photodetector to establish its operating point, influencing its response characteristics.

    The external voltage applied to a photodetector to establish its operating point, influencing its response characteristics.

  • Blue LEDs (450nm – 475nm)

    LEDs made from indium gallium nitride (InGaN), primarily used for creating white light with phosphors.

    LEDs made from indium gallium nitride (InGaN), primarily used for creating white light with phosphors.

    Related: IR emitters and LEDs from Opto Diode.

  • Bond Wire Damage

    Damage to the wire bonds connecting the photodiode die to the package pins can cause device failure. Users should avoid pressing the wire onto the die to prevent shorts. Warranty is void if the wire is broken by the user.

    Damage to the wire bonds connecting the photodiode die to the package pins can cause device failure. Users should avoid pressing the wire onto the die to prevent shorts. Warranty is void if the wire is broken by the user.

  • Calibration

    The process of determining a photodiode’s responsivity across specific wavelengths, ensuring accuracy in intensity measurements.

    The process of determining a photodiode's responsivity across specific wavelengths, ensuring accuracy in intensity measurements.

  • Candela

    A measure of luminous intensity, indicating the perceived brightness of a light source.

    A measure of luminous intensity, indicating the perceived brightness of a light source.

  • Capacitance (C)

    The ability of a photodiode to store charge, typically measured in picofarads (pF). It affects the speed and frequency response of the device.

    The ability of a photodiode to store charge, typically measured in picofarads (pF). It affects the speed and frequency response of the device.

  • Capacitively Coupled Bias Tee

    A device (e.g., IRD model BT-250) used to reverse bias photodiodes while blocking DC signals. This increases the
    photodiode’s response speed and saturation threshold during high-flux measurements.

    A device (e.g., IRD model BT-250) used to reverse bias photodiodes while blocking DC signals. This increases the photodiode's response speed and saturation threshold during high-flux measurements.

  • Carbon K Edge

    An absorption feature observed in the spectral response of photodiodes due to carbon contamination on beamline optics.

    An absorption feature observed in the spectral response of photodiodes due to carbon contamination on beamline optics.

  • Carrier Collection Efficiency

    The percentage of photogenerated carriers (electron-hole pairs) successfully collected by the photodiode, ideally near 100% in AXUV photodiodes.

    The percentage of photogenerated carriers (electron-hole pairs) successfully collected by the photodiode, ideally near 100% in AXUV photodiodes.

    Related: AXUV photodiodes from Opto Diode.

  • Carrier Recombination

    The process where photogenerated electron-hole pairs recombine before contributing to the current. Radiation damage can increase surface recombination, reducing efficiency.

    The process where photogenerated electron-hole pairs recombine before contributing to the current. Radiation damage can increase surface recombination, reducing efficiency.

  • Charge (Q)

    The total electrical charge generated in a photodiode by incident photons.

    The total electrical charge generated in a photodiode by incident photons.

  • Charge Carrier Generation

    The creation of electron-hole pairs in the silicon layer of a photodiode when exposed to radiation.

    The creation of electron-hole pairs in the silicon layer of a photodiode when exposed to radiation.

  • Charge Collection Efficiency

    Refers to the percentage of electron-hole pairs generated by photon energy that are successfully collected. In AXUV photodiodes, this efficiency approaches 100% beneath the silicon dioxide layer.

    Refers to the percentage of electron-hole pairs generated by photon energy that are successfully collected. In AXUV photodiodes, this efficiency approaches 100% beneath the silicon dioxide layer.

    Related: AXUV photodiodes from Opto Diode.

  • Charge Transport from Oxide

    The phenomenon where charge carriers generated in the oxide layer contribute to photocurrent, influencing quantum yield at short wavelengths.

    The phenomenon where charge carriers generated in the oxide layer contribute to photocurrent, influencing quantum yield at short wavelengths.

  • Chopper

    Not required for detectors measuring pulsed laser beams, as modulation is inherent. Used to increase the signal-to-noise ratio by modulating the source.

    Not required for detectors measuring pulsed laser beams, as modulation is inherent. Used to increase the signal-to-noise ratio by modulating the source.

  • Cleaning Methodology

    Windowless photodiodes and filtered diodes with carbon or silicon passivating coatings can be cleaned using a gentle swabbing action with electronic-grade acetone or alcohol.

    Windowless photodiodes and filtered diodes with carbon or silicon passivating coatings can be cleaned using a gentle swabbing action with electronic-grade acetone or alcohol.

  • Coated Photodiodes

    Photodiodes with thin metallic coatings to block visible light and define wavelength bandpasses.

    Photodiodes with thin metallic coatings to block visible light and define wavelength bandpasses.

  • Collection Efficiency

    The percentage of photogenerated carriers successfully collected by the photodiode.

    The percentage of photogenerated carriers successfully collected by the photodiode.

  • Color Rendering Index (CRI)

    A scale (0-100) that measures a light source’s ability to accurately reveal the true colors of objects compared to natural sunlight.

    A scale (0-100) that measures a light source's ability to accurately reveal the true colors of objects compared to natural sunlight.

  • Color Stability

    The ability of LEDs to maintain consistent color output over temperature changes.

    The ability of LEDs to maintain consistent color output over temperature changes.

    Related: IR emitters and LEDs from Opto Diode.

  • Condensables

    Contaminants within the vacuum system that can form surface films on the photodiode.

    Contaminants within the vacuum system that can form surface films on the photodiode.

  • Constant Current Source

    A more efficient and stable circuit for driving LEDs, ensuring consistent current.

    A more efficient and stable circuit for driving LEDs, ensuring consistent current.

    Related: IR emitters and LEDs from Opto Diode.

  • Constant Pair Creation Energy

    An assumed value for the energy required to generate an electron-hole pair in silicon, approximately 3.70 eV.

    An assumed value for the energy required to generate an electron-hole pair in silicon, approximately 3.70 eV.

  • Continuous Wave (CW) Responsivity

    The photodiode’s sensitivity to steady-state light sources.

    The photodiode's sensitivity to steady-state light sources.

  • Control Electronics

    External circuitry responsible for controlling temperature and preventing overheating of the thermoelectric cooler.

    External circuitry responsible for controlling temperature and preventing overheating of the thermoelectric cooler.

  • Conversion Efficiency

    The efficiency of converting incident photon energy into electron-hole pairs in silicon photodiodes.

    The efficiency of converting incident photon energy into electron-hole pairs in silicon photodiodes.

  • Coulombic Collisions

    Interactions between ions and detector nuclei that do not contribute to the generation of electron-hole pairs.

    Interactions between ions and detector nuclei that do not contribute to the generation of electron-hole pairs.

  • Covert Illumination (940nm)

    Near-infrared LEDs used for covert applications like CCD-based systems or night vision equipment.

    Near-infrared LEDs used for covert applications like CCD-based systems or night vision equipment.

    Related: IR emitters and LEDs from Opto Diode.

  • Cryogenic Radiometry

    A precise method to measure radiation intensity by using cryogenically cooled systems.

    A precise method to measure radiation intensity by using cryogenically cooled systems.

  • Current Limit

    The maximum allowable current that can flow through the thermoelectric cooler to prevent overheating.

    The maximum allowable current that can flow through the thermoelectric cooler to prevent overheating.

  • Current Limiting Resistor

    A resistor used in basic LED circuits to regulate current and prevent overheating.

    A resistor used in basic LED circuits to regulate current and prevent overheating.

    Related: IR emitters and LEDs from Opto Diode.

  • Current Measurement

    The process of recording photocurrent generated by the photodiode in response to incident radiation.

    The process of recording photocurrent generated by the photodiode in response to incident radiation.

  • Curve Fitting

    A method to smooth experimental data, such as responsivity changes, to identify patterns and discrepancies influenced by factors like photon energy deposition depth.

    A method to smooth experimental data, such as responsivity changes, to identify patterns and discrepancies influenced by factors like photon energy deposition depth.

  • Custom Photodiodes

    Photodiodes specifically designed and manufactured to meet unique application requirements beyond standard specifications.

    Photodiodes specifically designed and manufactured to meet unique application requirements beyond standard specifications.

  • Custom Silicon Thickness

    AXUV photodiodes can be manufactured with customized silicon thickness to suit specific photon energy detection requirements.

    AXUV photodiodes can be manufactured with customized silicon thickness to suit specific photon energy detection requirements.

    Related: AXUV photodiodes from Opto Diode.

  • Cutoff Frequency (fc) Hz

    A measure of detector response speed.

    A measure of detector response speed.

  • Cutoff Wavelength

    The maximum wavelength of light that a photodiode can detect.

    The maximum wavelength of light that a photodiode can detect.

  • Cutoff Wavelength (λc) µm

    The wavelength at which detector D* has degraded to one half of its peak value.

    The wavelength at which detector D* has degraded to one half of its peak value.

  • Dark Current

    The small electric current that flows through a photodetector even in the absence of light, typically due to thermal generation of carriers.

    The small electric current that flows through a photodetector even in the absence of light, typically due to thermal generation of carriers.

  • Dark Resistance

    The resistance of a photoconductive detector in the absence of incident radiation, affecting the detector’s noise characteristics and sensitivity.

    D-Star (D) cm Hz½ W⁻¹*: The figure of merit for describing an infrared detector’s signal-to-noise ratio (S/N), normalized to a detector active area of 1 cm² and a noise equivalent bandwidth of 1 Hz.

    The resistance of a photoconductive detector in the absence of incident radiation, affecting the detector's noise characteristics and sensitivity.

    D-Star (D) cm Hz½ W⁻¹*: The figure of merit for describing an infrared detector's signal-to-noise ratio (S/N), normalized to a detector active area of 1 cm² and a noise equivalent bandwidth of 1 Hz.

  • Dead Layer Absorption (ΔDL)

    Losses caused by photon or electron interactions in non-active regions of the photodiode.

    Losses caused by photon or electron interactions in non-active regions of the photodiode.

  • Degradation Resistance

    UVG photodiodes show exceptional resistance to responsivity degradation, even under intense UV flux and high humidity conditions.

    UVG photodiodes show exceptional resistance to responsivity degradation, even under intense UV flux and high humidity conditions.

    Related: UVG photodiodes from Opto Diode.

  • Delta-Doped Silicon Detectors

    Advanced detectors with reduced entrance window thickness, allowing detection of ions and electrons at energies below 2 keV.

    Advanced detectors with reduced entrance window thickness, allowing detection of ions and electrons at energies below 2 keV.

  • Depth of Photon Energy Deposition

    The average depth in the photodiode where photon energy is absorbed, affecting responsivity changes.

    *Detectivity (D)**: A figure of merit for photodetectors, representing their sensitivity by quantifying the ability to detect weak signals. Higher detectivity indicates better performance.

    The average depth in the photodiode where photon energy is absorbed, affecting responsivity changes.

    *Detectivity (D)**: A figure of merit for photodetectors, representing their sensitivity by quantifying the ability to detect weak signals. Higher detectivity indicates better performance.

  • Detector Field of View (FOV)

    The angular extent over which a detector is sensitive to incoming light, determining the area from which it can detect radiation.

    The angular extent over which a detector is sensitive to incoming light, determining the area from which it can detect radiation.

  • Detector Package

    The assembly containing the infrared detector and thermoelectric cooler, designed for enhanced sensitivity and reliability.

    The assembly containing the infrared detector and thermoelectric cooler, designed for enhanced sensitivity and reliability.

  • DT (Delta T)

    The differential temperature generated by the thermoelectric cooler due to the Peltier effect, representing the temperature difference between the cooled object and the heat sink.

    The differential temperature generated by the thermoelectric cooler due to the Peltier effect, representing the temperature difference between the cooled object and the heat sink.

  • Dynamic Range

    AXUV photodiodes offer a large dynamic range, operating effectively over eight orders of magnitude of light intensity.

    AXUV photodiodes offer a large dynamic range, operating effectively over eight orders of magnitude of light intensity.

    Related: AXUV photodiodes from Opto Diode.

  • Effective Area Size

    The active region of a photodetector that contributes to the generation of photocurrent, influencing the device’s sensitivity and response time.

    The active region of a photodetector that contributes to the generation of photocurrent, influencing the device's sensitivity and response time.

  • Effective Silicon Thickness

    The thickness of the silicon layer that contributes to photon absorption and carrier generation, affecting responsivity.

    The thickness of the silicon layer that contributes to photon absorption and carrier generation, affecting responsivity.

  • Effective Transmittance

    The ratio of light transmitted through a photodiode’s multilayer coating to the light transmitted through an uncoated photodiode. Used to evaluate the performance of coatings.

    The ratio of light transmitted through a photodiode's multilayer coating to the light transmitted through an uncoated photodiode. Used to evaluate the performance of coatings.

  • Efficiency Drop

    A reduction in quantum efficiency due to surface recombination or radiation damage, particularly at specific photon energies like the Si L edge (99.8 eV).

    A reduction in quantum efficiency due to surface recombination or radiation damage, particularly at specific photon energies like the Si L edge (99.8 eV).

  • Electron Detection

    The capability of certain photodiodes to detect electrons, making them suitable for applications requiring electron sensitivity.

    The capability of certain photodiodes to detect electrons, making them suitable for applications requiring electron sensitivity.

  • Electron Gain (Ge)

    The number of charges generated per incident electron, calculated using the formula Ge=R⋅ϵGe = R \cdot \epsilonGe=R⋅ϵ, where RRR is responsivity and ϵ\epsilonϵ is incident energy.

    The number of charges generated per incident electron, calculated using the formula Ge=R⋅ϵGe = R \cdot \epsilonGe=R⋅ϵ, where RRR is responsivity and ϵ\epsilonϵ is incident energy.

  • Electron-Hole Pair Creation Energy (W)

    The energy required to generate an electron-hole pair in silicon. A value of 3.70 eV is typically assumed for photon energies above 40 eV.

    The energy required to generate an electron-hole pair in silicon. A value of 3.70 eV is typically assumed for photon energies above 40 eV.

  • Electron-Hole Pairs

    Pairs of electrons and holes generated when photons or particles interact with the silicon layer in the photodiode.

    Pairs of electrons and holes generated when photons or particles interact with the silicon layer in the photodiode.

  • Element Size and Area (L, W) mm and (Ad) cm²

    L: The distance between detector electrodes (length).

    W: The width of the active area.

    Ad: The active area (L×WL \times WL×W) responsible for generating signal and noise.

    <b>L:</b> The distance between detector electrodes (length).

    <b>W:</b> The width of the active area.

    <b>Ad:</b> The active area (L×WL \times WL×W) responsible for generating signal and noise.

  • Element Spacing

    The non-active distance between detectors in an array.

    Pitch: The center-to-center distance between active detectors in an array.

    The non-active distance between detectors in an array.

    <b>Pitch:</b> The center-to-center distance between active detectors in an array.

  • Element Spacing and Pitch mm
  • Element Temperature (Td) °C

    The operating temperature of the detector element, often equivalent to ambient temperature for uncooled detectors.

    The operating temperature of the detector element, often equivalent to ambient temperature for uncooled detectors.

  • Energy Savings

    LEDs are highly efficient, offering significant cost savings over filtered incandescent lamps in applications like architectural lighting and traffic signals.

    LEDs are highly efficient, offering significant cost savings over filtered incandescent lamps in applications like architectural lighting and traffic signals.

    Related: IR emitters and LEDs from Opto Diode.

  • Environmental Resistance

    SXUV photodiodes are resistant to environmental contaminants, such as moisture, maintaining responsivity even after prolonged exposure to 100% relative humidity.

    SXUV photodiodes are resistant to environmental contaminants, such as moisture, maintaining responsivity even after prolonged exposure to 100% relative humidity.

    Related: SXUV photodiodes from Opto Diode.

  • EUV Filtering Materials

    Materials such as aluminum, silver, and titanium/carbon coatings that restrict photodiode sensitivity to extreme ultraviolet wavelengths.

    Materials such as aluminum, silver, and titanium/carbon coatings that restrict photodiode sensitivity to extreme ultraviolet wavelengths.

  • EUV Reflectance

    The reflectivity of photodiode coatings in the extreme ultraviolet range, influenced by multilayer structures and surface conditions.

    The reflectivity of photodiode coatings in the extreme ultraviolet range, influenced by multilayer structures and surface conditions.

  • Excimer Laser Applications

    SXUV photodiodes are optimized for excimer laser feedback loops and high-flux pulsed laser measurements.

    SXUV photodiodes are optimized for excimer laser feedback loops and high-flux pulsed laser measurements.

    Related: SXUV photodiodes from Opto Diode.

  • External Quantum Efficiency

    The ratio of electron-hole pairs produced to incident photons, used to evaluate photodiode performance.

    The ratio of electron-hole pairs produced to incident photons, used to evaluate photodiode performance.

  • Eye Safety

    Unlike lasers, LEDs do not pose significant eye safety concerns, making them safer for general use.

    Unlike lasers, LEDs do not pose significant eye safety concerns, making them safer for general use.

    Related: IR emitters and LEDs from Opto Diode.

  • Faraday Cup

    A device used to measure the ion beam current during photodiode testing, ensuring stable ion incidence.

    A device used to measure the ion beam current during photodiode testing, ensuring stable ion incidence.

  • Feedback Loops

    Systems using SXUV photodiodes to monitor and control energy levels in excimer laser pulses.

    Systems using SXUV photodiodes to monitor and control energy levels in excimer laser pulses.

    Related: SXUV photodiodes from Opto Diode.

  • Field of View (FOV)

    The angular extent over which a detector is sensitive to incoming light, determining the area from which it can detect radiation.

    The angular extent over which a detector is sensitive to incoming light, determining the area from which it can detect radiation.

  • Filter Film Deposition

    A fabrication process where thin films of EUV filtering materials are applied to photodiodes, ensuring high-quality optical coatings.

    A fabrication process where thin films of EUV filtering materials are applied to photodiodes, ensuring high-quality optical coatings.

  • Filtered Diodes

    EUV photodiodes with carbon or silicon passivation layers can be cleaned gently with electronic-grade acetone or alcohol. For other filter types, consultation with the manufacturer is recommended.

    EUV photodiodes with carbon or silicon passivation layers can be cleaned gently with electronic-grade acetone or alcohol. For other filter types, consultation with the manufacturer is recommended.

  • Filtered Lamps

    Conventional lamps with color filters; less efficient and precise than monochromatic LEDs.

    Conventional lamps with color filters; less efficient and precise than monochromatic LEDs.

    Related: IR emitters and LEDs from Opto Diode.

  • Fluence

    The total photon energy received by a photodiode surface, expressed in J/cm² or photons/cm². SXUV diodes exhibit less than 3% response variation even after high fluence exposure.

    The total photon energy received by a photodiode surface, expressed in J/cm² or photons/cm². SXUV diodes exhibit less than 3% response variation even after high fluence exposure.

    Related: SXUV photodiodes from Opto Diode.

  • Fluorescent Lamps

    Have a CRI between 60-65, resulting in poor color rendering compared to sunlight or LEDs.

    Have a CRI between 60-65, resulting in poor color rendering compared to sunlight or LEDs.

    Related: IR emitters and LEDs from Opto Diode.

  • Frequency Response

    The range of modulation frequencies over which a photodetector can effectively respond, indicating its ability to detect varying signal frequencies.

    The range of modulation frequencies over which a photodetector can effectively respond, indicating its ability to detect varying signal frequencies.

  • Fresnel Coefficients

    Complex numbers used to calculate reflectance and transmittance at the interface between layers of a photodiode, affecting its responsivity.

    Complex numbers used to calculate reflectance and transmittance at the interface between layers of a photodiode, affecting its responsivity.

  • Full-Width Half-Maximum (FWHM)

    A measure of the spectral width of a photodiode’s responsivity curve, indicating its wavelength selectivity.

    A measure of the spectral width of a photodiode's responsivity curve, indicating its wavelength selectivity.

  • GaAlAs Photodiode

    A photodiode with a buried junction and graded bandgap structure, offering wavelength-specific detection in the 850–910 nm range.

    A photodiode with a buried junction and graded bandgap structure, offering wavelength-specific detection in the 850–910 nm range.

  • Gallium Nitride (GaN)

    A material used for ultraviolet (UV) LEDs, enabling wavelengths as low as 360nm, primarily for industrial curing and biomedical applications.

    A material used for ultraviolet (UV) LEDs, enabling wavelengths as low as 360nm, primarily for industrial curing and biomedical applications.

    Related: IR emitters and LEDs from Opto Diode.

  • Green LEDs (520nm – 530nm)

    LEDs used in traffic signal lighting, fabricated from InGaN materials.

    LEDs used in traffic signal lighting, fabricated from InGaN materials.

    Related: IR emitters and LEDs from Opto Diode.

  • Heatsink

    A component used to dissipate heat generated by the detector and thermoelectric cooler. Proper heatsink design and mounting are critical for thermal resistance minimization and device longevity.

    A component used to dissipate heat generated by the detector and thermoelectric cooler. Proper heatsink design and mounting are critical for thermal resistance minimization and device longevity.

  • Hermetic Seal

    A glass-filled seal around the pins of the detector package to prevent moisture or contaminants from affecting the detector’s performance.

    A glass-filled seal around the pins of the detector package to prevent moisture or contaminants from affecting the detector's performance.

  • High Color Rendering Index (High CRI)

    LEDs with RGB or RGBA configurations produce light with higher CRI, making colors appear more true to life.

    LEDs with RGB or RGBA configurations produce light with higher CRI, making colors appear more true to life.

    Related: IR emitters and LEDs from Opto Diode.

  • High Reliability

    LEDs are more durable and reliable than lasers, with longer lifespans and lower maintenance costs.

    LEDs are more durable and reliable than lasers, with longer lifespans and lower maintenance costs.

    Related: IR emitters and LEDs from Opto Diode.

  • Hydrogen Ion Detection

    AXUV photodiodes can detect hydrogen ions and low-energy electrons with near-theoretical quantum efficiency.

    AXUV photodiodes can detect hydrogen ions and low-energy electrons with near-theoretical quantum efficiency.

    Related: AXUV photodiodes from Opto Diode.

  • Illumination Applications

    Applications like museum lighting, map reading, or wire identification, where accurate color rendering is crucial.

    Applications like museum lighting, map reading, or wire identification, where accurate color rendering is crucial.

  • Indium Gallium Nitride (InGaN)

    A semiconductor material used in LEDs emitting from near UV to green wavelengths (395nm – 530nm).

    A semiconductor material used in LEDs emitting from near UV to green wavelengths (395nm - 530nm).

    Related: IR emitters and LEDs from Opto Diode.

  • Infrared (IR) Detectors

    Devices designed to detect infrared radiation, commonly used in applications such as remote controls, night vision, and thermal imaging.

    Devices designed to detect infrared radiation, commonly used in applications such as remote controls, night vision, and thermal imaging.

  • Infrared LEDs (800nm – 900nm)

    LEDs used in night vision illumination, industrial photocontrols, and covert applications, made from AlGaAs or GaAs materials.

    LEDs used in night vision illumination, industrial photocontrols, and covert applications, made from AlGaAs or GaAs materials.

    Related: IR emitters and LEDs from Opto Diode.

  • Infrared LEDs (800nm – 940nm)

    Used for applications like night vision illuminators, photoelectric controls, and covert illumination systems.

    Used for applications like night vision illuminators, photoelectric controls, and covert illumination systems.

    Related: IR emitters and LEDs from Opto Diode.

  • Interface Material

    A substance, such as thermal compound or thermal pad, placed between the package and heatsink to reduce thermal resistance and ensure efficient heat transfer.

    A substance, such as thermal compound or thermal pad, placed between the package and heatsink to reduce thermal resistance and ensure efficient heat transfer.

  • Internal Quantum Efficiency (IQE)

    A measure of the number of electron-hole pairs generated per absorbed photon. UVG photodiodes have 100% IQE in the UV and visible spectrum, with minimal photogenerated carrier recombination.

    A measure of the number of electron-hole pairs generated per absorbed photon. UVG photodiodes have 100% IQE in the UV and visible spectrum, with minimal photogenerated carrier recombination.

    Related: UVG photodiodes from Opto Diode.

  • Latent Recombination Centers

    Defects caused by impurities that lead to long-term degradation in quantum efficiency. UVG photodiodes are fabricated in clean environments to minimize such effects.

    Defects caused by impurities that lead to long-term degradation in quantum efficiency. UVG photodiodes are fabricated in clean environments to minimize such effects.

    Related: UVG photodiodes from Opto Diode.

  • LED Controllers

    Devices used to regulate multicolor LED arrays, ensuring consistent color output and enabling the creation of custom colors from violet to red.

    Devices used to regulate multicolor LED arrays, ensuring consistent color output and enabling the creation of custom colors from violet to red.

    Related: IR emitters and LEDs from Opto Diode.

  • LED Wavelength

    The specific color of light emitted by an LED, measured in nanometers (nm). Each wavelength is suited to a specific application.

    The specific color of light emitted by an LED, measured in nanometers (nm). Each wavelength is suited to a specific application.

    Related: IR emitters and LEDs from Opto Diode.

  • Light Emitting Diode (LED)

    A semiconductor device that emits light when an electrical current flows through it in the forward direction. Emitted light is determined by the bandgap of the material.

    A semiconductor device that emits light when an electrical current flows through it in the forward direction. Emitted light is determined by the bandgap of the material.

    Related: IR emitters and LEDs from Opto Diode.

  • Light Engine

    A system combining LEDs with controllers to create custom lighting solutions for specific applications.

    A system combining LEDs with controllers to create custom lighting solutions for specific applications.

    Related: IR emitters and LEDs from Opto Diode.

  • Lime Green LEDs (565nm)

    LEDs with limited applications due to market demand, fabricated from AlInGaP materials.

    LEDs with limited applications due to market demand, fabricated from AlInGaP materials.

    Related: IR emitters and LEDs from Opto Diode.

  • Linear Range

    The range over which photodiodes operate linearly. Applying a small reverse bias voltage extends the linear range and increases saturation limits in high radiation conditions.

    The range over which photodiodes operate linearly. Applying a small reverse bias voltage extends the linear range and increases saturation limits in high radiation conditions.

  • Linear Responsivity

    Responsivity that remains proportional to the incident radiation intensity. AXUV photodiodes exhibit minimal variation in linear responsivity across a broad spectral range.

    Responsivity that remains proportional to the incident radiation intensity. AXUV photodiodes exhibit minimal variation in linear responsivity across a broad spectral range.

    Related: AXUV photodiodes from Opto Diode.

  • Linearity

    The characteristic of a photodetector where the output signal is directly proportional to the incident light intensity over a specified range, ensuring accurate measurements.

    The characteristic of a photodetector where the output signal is directly proportional to the incident light intensity over a specified range, ensuring accurate measurements.

  • Load Resistor (RL) ohms

    A resistor in the bias circuit connected in series with the detector.

    A resistor in the bias circuit connected in series with the detector.

  • Long-Wave Pass Filters

    Optical filters used to block short-wavelength light while allowing longer wavelengths to pass through, enhancing selectivity in silicon photodiodes.

    Optical filters used to block short-wavelength light while allowing longer wavelengths to pass through, enhancing selectivity in silicon photodiodes.

  • Low-Energy Ion Detection

    The ability of solid-state detectors to measure ions with energies as low as 1 keV, depending on the reduction of losses like recombination and Coulombic collisions.

    The ability of solid-state detectors to measure ions with energies as low as 1 keV, depending on the reduction of losses like recombination and Coulombic collisions.

  • Lyman Alpha Line

    A specific wavelength in the ultraviolet spectrum (around 121.6 nm) for which specialized photodiodes with narrow bandpasses are designed.

    A specific wavelength in the ultraviolet spectrum (around 121.6 nm) for which specialized photodiodes with narrow bandpasses are designed.

  • Market Potential

    A critical factor determining whether LEDs of specific wavelengths are commercially available. High-volume applications drive advancements in certain ranges.

    A critical factor determining whether LEDs of specific wavelengths are commercially available. High-volume applications drive advancements in certain ranges.

    Related: IR emitters and LEDs from Opto Diode.

  • Maximum Bias

    The value of bias voltage which yields maximum signal.

    The value of bias voltage which yields maximum signal.

  • Mirror-Based X-Ray Rejection

    Using a grazing incidence mirror in conjunction with coated photodiodes to reduce sensitivity to X-rays.

    Using a grazing incidence mirror in conjunction with coated photodiodes to reduce sensitivity to X-rays.

  • Modeling Responsivity

    Using mathematical models to predict photodiode responses based on parameters like oxide thickness, absorption coefficients, and pair creation energy.

    Using mathematical models to predict photodiode responses based on parameters like oxide thickness, absorption coefficients, and pair creation energy.

  • Monochromatic LEDs

    LEDs emitting a single wavelength, offering advantages like precise spectral output and energy efficiency compared to filtered white light sources.

    LEDs emitting a single wavelength, offering advantages like precise spectral output and energy efficiency compared to filtered white light sources.

    Related: IR emitters and LEDs from Opto Diode.

  • Mounting

    The process of attaching the detector package to the heatsink. Proper mounting involves ensuring flat and smooth contact surfaces to minimize thermal resistance and avoid hermetic seal failure.

    The process of attaching the detector package to the heatsink. Proper mounting involves ensuring flat and smooth contact surfaces to minimize thermal resistance and avoid hermetic seal failure.

  • Multi-Color Detectors

    Photodetectors capable of sensing multiple wavelengths or colors simultaneously, enabling applications like colorimetry and multi-spectral imaging.

    Photodetectors capable of sensing multiple wavelengths or colors simultaneously, enabling applications like colorimetry and multi-spectral imaging.

  • Multilayer Coating

    A reflective and transmissive coating, often consisting of materials like molybdenum and silicon (Mo/Si). Used to enhance polarization selectivity and performance in photodiodes.

    A reflective and transmissive coating, often consisting of materials like molybdenum and silicon (Mo/Si). Used to enhance polarization selectivity and performance in photodiodes.

  • Near-Infrared LEDs

    LEDs in the range of 800nm – 900nm, used for night vision and remote controls.

    LEDs in the range of 800nm - 900nm, used for night vision and remote controls.

    Related: IR emitters and LEDs from Opto Diode.

  • Night Vision Illuminators (800nm – 850nm)

    Near-infrared LEDs used with night vision goggles or CCD systems for low-light or covert operations.

    Near-infrared LEDs used with night vision goggles or CCD systems for low-light or covert operations.

    Related: IR emitters and LEDs from Opto Diode.

  • Noise Equivalent Power (NEP) Watts

    The incident signal radiation required to yield a signal-to-noise ratio of one. NEP depends on source temperature, chopping frequency, noise equivalent bandwidth, field of view, and background temperature.

    The incident signal radiation required to yield a signal-to-noise ratio of one. NEP depends on source temperature, chopping frequency, noise equivalent bandwidth, field of view, and background temperature.

  • Noise Performance

    AXUV photodiodes exhibit very low noise, making them suitable for sensitive measurements in satellite and space applications.

    AXUV photodiodes exhibit very low noise, making them suitable for sensitive measurements in satellite and space applications.

    Related: AXUV photodiodes from Opto Diode.

  • Nuclear Stopping Defect (DN)

    Energy lost by incident ions to nuclear interactions within the detector material, representing a fundamental limit in low-energy ion detection.

    Energy lost by incident ions to nuclear interactions within the detector material, representing a fundamental limit in low-energy ion detection.

  • Operating Temperature

    The range of ambient temperatures within which a photodetector can operate effectively without performance degradation.
    Optimum Bias – The value of bias voltage which yields maximum signal-to-noise ratio.

    The range of ambient temperatures within which a photodetector can operate effectively without performance degradation. Optimum Bias - The value of bias voltage which yields maximum signal-to-noise ratio.

  • Optical Constants

    Material-specific values, such as refractive indices and absorption coefficients, used to model the performance of photodiode coatings.

    Material-specific values, such as refractive indices and absorption coefficients, used to model the performance of photodiode coatings.

  • Overfilling the Diode

    When light energy spills over the diode’s active area, quantum efficiency decreases in peripheral areas, leading to inaccurate measurements. Large-area detectors are recommended for wide beams.

    When light energy spills over the diode’s active area, quantum efficiency decreases in peripheral areas, leading to inaccurate measurements. Large-area detectors are recommended for wide beams.

  • Passivating Layer

    A thin silicon dioxide layer (typically 15 nm) applied to protect the photodiode surface, ensuring stability and reducing surface recombination.

    A thin silicon dioxide layer (typically 15 nm) applied to protect the photodiode surface, ensuring stability and reducing surface recombination.

  • Passivating Oxide Layer

    A silicon dioxide layer applied to photodiodes to prevent surface recombination and enhance stability in UV applications.

    A silicon dioxide layer applied to photodiodes to prevent surface recombination and enhance stability in UV applications.

  • Passivation Layer

    A protective coating that prevents degradation from environmental exposure. UVG photodiodes use a silicon oxynitride layer, which provides high radiation hardness and moisture resistance.

    A protective coating that prevents degradation from environmental exposure. UVG photodiodes use a silicon oxynitride layer, which provides high radiation hardness and moisture resistance.

    Related: UVG photodiodes from Opto Diode.

  • Peak Responsivity (Rλpk)

    The maximum responsivity value of a detector, expressed as R(pk,1000Hz)R(pk, 1000Hz)R(pk,1000Hz), where 1000Hz is the chopping frequency.

    The maximum responsivity value of a detector, expressed as R(pk,1000Hz)R(pk, 1000Hz)R(pk,1000Hz), where 1000Hz is the chopping frequency.

  • Peltier Effect

    The principle by which a thermoelectric cooler pumps heat from one surface to another when DC current is applied, creating a temperature difference (ΔT\Delta TΔT).

    The principle by which a thermoelectric cooler pumps heat from one surface to another when DC current is applied, creating a temperature difference (ΔT\Delta TΔT).

  • Phosphor-Pumped LEDs

    White LEDs created by combining a blue LED with a yellow phosphor coating. While efficient for general lighting, they have lower CRI values.

    White LEDs created by combining a blue LED with a yellow phosphor coating. While efficient for general lighting, they have lower CRI values.

    Related: IR emitters and LEDs from Opto Diode.

  • Phosphor-Pumped White LEDs

    White LEDs created by combining a blue LED with a yellow phosphor. Common for general illumination.

    White LEDs created by combining a blue LED with a yellow phosphor. Common for general illumination.

    Related: IR emitters and LEDs from Opto Diode.

  • Photoconductive Infrared Detectors and Emitters Equation

    Describes the relationship Rλ=S/WRλ = S / WRλ=S/W, where SSS is the signal (in volts or amps), and WWW is the incident radiant power (in watts).

    Describes the relationship Rλ=S/WRλ = S / WRλ=S/W, where SSS is the signal (in volts or amps), and WWW is the incident radiant power (in watts).

    Related: IR emitters and LEDs from Opto Diode.

  • Photocurrent

    The current generated by a photodiode in response to incident radiation. Photocurrent measurements are used to evaluate detector performance and responsivity.

    The current generated by a photodiode in response to incident radiation. Photocurrent measurements are used to evaluate detector performance and responsivity.

  • Photodiode Calibration

    The process of measuring and verifying the photodiode’s response to known radiation sources, such as synchrotron radiation, to ensure accuracy.

    The process of measuring and verifying the photodiode's response to known radiation sources, such as synchrotron radiation, to ensure accuracy.

  • Photodiode Sensitivity

    The ability of a photodiode to detect specific wavelengths. Sensitivity depends on the coating and the underlying silicon’s quantum efficiency.

    The ability of a photodiode to detect specific wavelengths. Sensitivity depends on the coating and the underlying silicon's quantum efficiency.

  • Photoemission

    The emission of electrons from a material surface due to incident radiation. Observed as negative currents in coated photodiodes under specific conditions.

    The emission of electrons from a material surface due to incident radiation. Observed as negative currents in coated photodiodes under specific conditions.

  • Photogenerated Carriers

    Electron-hole pairs created when photons are absorbed by the silicon layer of a photodiode.

    Electron-hole pairs created when photons are absorbed by the silicon layer of a photodiode.

  • Photon Energy

    The energy of incident photons, measured in electron volts (eV). Photodiodes exhibit varying responsivity depending on the photon energy and surface properties.

    The energy of incident photons, measured in electron volts (eV). Photodiodes exhibit varying responsivity depending on the photon energy and surface properties.

  • Photon Energy (Ep)

    The energy of individual photons, related to the wavelength of incident light. Photon energy is crucial for responsivity calculations.

    The energy of individual photons, related to the wavelength of incident light. Photon energy is crucial for responsivity calculations.

  • Photon Energy (Eph)

    Energy of incident photons, influencing the quantum efficiency of AXUV photodiodes, calculated using the formula Eph/3.7Eph / 3.7Eph/3.7.

    Energy of incident photons, influencing the quantum efficiency of AXUV photodiodes, calculated using the formula Eph/3.7Eph / 3.7Eph/3.7.

    Related: AXUV photodiodes from Opto Diode.

  • Photon Energy Deposition Depth

    The depth within the photodiode where photon energy is absorbed. This affects responsivity, with higher energy photons penetrating deeper into the device.

    The depth within the photodiode where photon energy is absorbed. This affects responsivity, with higher energy photons penetrating deeper into the device.

  • Photovoltaic Mode

    An operational mode of the photodiode where no external bias is applied, generating current solely from incident radiation.

    An operational mode of the photodiode where no external bias is applied, generating current solely from incident radiation.

  • Photovoltaic Operation

    AXUV photodiodes operate without external voltage, unlike tube-based detectors.

    AXUV photodiodes operate without external voltage, unlike tube-based detectors.

    Related: AXUV photodiodes from Opto Diode.

  • Picoammeter Testing

    A method to test photodiode functionality by measuring current under room light. Multimeters are not suitable for photodiode testing.

    A method to test photodiode functionality by measuring current under room light. Multimeters are not suitable for photodiode testing.

  • Plasma Diagnostics

    Applications in fusion research, where AXUV photodiodes are used to measure radiated power and plasma profiles.

    Applications in fusion research, where AXUV photodiodes are used to measure radiated power and plasma profiles.

    Related: AXUV photodiodes from Opto Diode.

  • Polarization Performance

    The ability of a photodiode’s multilayer coating to differentiate between P-polarized and S-polarized light. Transmittance and reflectance profiles vary depending on polarization.

    The ability of a photodiode's multilayer coating to differentiate between P-polarized and S-polarized light. Transmittance and reflectance profiles vary depending on polarization.

  • Polarization Sensitivity

    The variation in photodiode responsivity with different light polarization states, important for specific designs like trap detectors.

    The variation in photodiode responsivity with different light polarization states, important for specific designs like trap detectors.

  • Portable LED Signage

    Low-power highway signs powered by small solar panels instead of generators, showcasing the energy efficiency of LEDs.

    Low-power highway signs powered by small solar panels instead of generators, showcasing the energy efficiency of LEDs.

    Related: IR emitters and LEDs from Opto Diode.

  • Power Responsivity

    The output current or voltage of a photodiode per unit of incident optical power, typically measured in amperes per watt (A/W).

    The output current or voltage of a photodiode per unit of incident optical power, typically measured in amperes per watt (A/W).

  • Power Supply

    The electronic device providing power to the thermoelectric cooler. It includes current limits and temperature controls to prevent overheating.

    The electronic device providing power to the thermoelectric cooler. It includes current limits and temperature controls to prevent overheating.

  • Protective Cover

    The protective cover on windowless photodiodes must remain in place until the device is fully assembled into the next level of integration to avoid contamination, damage, or bond wire breakage.

    The protective cover on windowless photodiodes must remain in place until the device is fully assembled into the next level of integration to avoid contamination, damage, or bond wire breakage.

  • Protective Epoxy

    A coating on UVG photodiodes to protect wire bonds. Devices must operate near room temperature to avoid thermal stress on the epoxy.

    A coating on UVG photodiodes to protect wire bonds. Devices must operate near room temperature to avoid thermal stress on the epoxy.

    Related: UVG photodiodes from Opto Diode.

  • Pulse Energy Measurement

    Energy per pulse calculated using: Energy per Pulse=Q⋅Ep/QE\text{Energy per Pulse} = Q \cdot Ep / QEEnergy per Pulse=Q⋅Ep/QE

    Where QQQ is charge, EpEpEp is photon energy, and QEQEQE is quantum efficiency.

    Energy per pulse calculated using: Energy per Pulse=Q⋅Ep/QE\text{Energy per Pulse} = Q \cdot Ep / QEEnergy per Pulse=Q⋅Ep/QE

    Where QQQ is charge, EpEpEp is photon energy, and QEQEQE is quantum efficiency.

  • Pulse Height Defect (DPHD)

    The discrepancy between the total energy of an incident ion and the energy contributing to the detector’s output signal.

    The discrepancy between the total energy of an incident ion and the energy contributing to the detector's output signal.

  • Pulse Width Modulation (PWM)

    A method for controlling LED brightness by rapidly switching the LED on and off.

    A method for controlling LED brightness by rapidly switching the LED on and off.

    Related: IR emitters and LEDs from Opto Diode.

  • Radiation Hardness

    SXUV photodiodes are designed to withstand extreme radiation environments, maintaining stable responsivity after exposure to fluences exceeding 102210^{22}1022 photons/cm².

    SXUV photodiodes are designed to withstand extreme radiation environments, maintaining stable responsivity after exposure to fluences exceeding 102210^{22}1022 photons/cm².

    Related: SXUV photodiodes from Opto Diode.

  • Radiation-Hard Silicon Dioxide Window

    The protective entrance window of AXUV photodiodes, designed to minimize quantum efficiency losses while being resilient to radiation.

    The protective entrance window of AXUV photodiodes, designed to minimize quantum efficiency losses while being resilient to radiation.

    Related: AXUV photodiodes from Opto Diode.

  • Recombination Loss

    Energy loss due to the recombination of electron-hole pairs before they are collected by the detector, minimized in advanced solid-state detectors.

    Energy loss due to the recombination of electron-hole pairs before they are collected by the detector, minimized in advanced solid-state detectors.

  • Red LEDs (625nm)

    High-efficiency LEDs used in traffic signals and part of RGB systems for white light creation. Made using AlInGaP materials.

    High-efficiency LEDs used in traffic signals and part of RGB systems for white light creation. Made using AlInGaP materials.

    Related: IR emitters and LEDs from Opto Diode.

  • Red LEDs (630nm – 640nm)

    Used in traffic signal lights and RGB white light systems.

    Used in traffic signal lights and RGB white light systems.

    Related: IR emitters and LEDs from Opto Diode.

  • Reflectance

    The fraction of incident radiation reflected by a photodiode’s surface. Minimizing reflectance improves detector efficiency, especially in UV applications.

    The fraction of incident radiation reflected by a photodiode's surface. Minimizing reflectance improves detector efficiency, especially in UV applications.

  • Reflectance Profiles

    A graph of reflectance efficiency at different wavelengths, showing variations in S- and P-polarized light for multilayer-coated photodiodes.

    A graph of reflectance efficiency at different wavelengths, showing variations in S- and P-polarized light for multilayer-coated photodiodes.

  • Relative Signal-to-Noise Ratio (SNR)

    A measure of the signal strength relative to background noise, used to evaluate photodiode performance under different lighting conditions.

    A measure of the signal strength relative to background noise, used to evaluate photodiode performance under different lighting conditions.

  • Reliability

    The durability and operational stability of the detector package, influenced by proper handling, mounting, and temperature control.

    The durability and operational stability of the detector package, influenced by proper handling, mounting, and temperature control.

  • Residual Loss Effects (ΔR)

    Losses caused by electron-hole recombination in the photodiode, minimized in AXUV photodiodes.

    Losses caused by electron-hole recombination in the photodiode, minimized in AXUV photodiodes.

    Related: AXUV photodiodes from Opto Diode.

  • Resistor-Limited LED Circuit

    A basic circuit using a resistor to limit LED current, suitable for narrow temperature ranges and non-critical applications.

    A basic circuit using a resistor to limit LED current, suitable for narrow temperature ranges and non-critical applications.

    Related: IR emitters and LEDs from Opto Diode.

  • Response Speed

    The speed at which a photodetector can respond to changes in light intensity, typically characterized by its rise and fall times.

    The speed at which a photodetector can respond to changes in light intensity, typically characterized by its rise and fall times.

  • Responsivity

    The ratio of the electrical output of a photodetector to the optical input, usually expressed in amperes per watt (A/W), indicating the device’s efficiency in converting light to an electrical signal.

    The ratio of the electrical output of a photodetector to the optical input, usually expressed in amperes per watt (A/W), indicating the device's efficiency in converting light to an electrical signal.

  • Responsivity Stability

    he ability of SXUV photodiodes to maintain consistent responsivity even under high-intensity radiation or prolonged use. For example, exposure to 193 nm and 157 nm radiation showed minimal degradation.

    he ability of SXUV photodiodes to maintain consistent responsivity even under high-intensity radiation or prolonged use. For example, exposure to 193 nm and 157 nm radiation showed minimal degradation.

    Related: SXUV photodiodes from Opto Diode.

  • Responsivity Stability

    The consistency of a photodiode’s output signal relative to its input radiation intensity, even under varying environmental conditions.

    The consistency of a photodiode's output signal relative to its input radiation intensity, even under varying environmental conditions.

  • Reverse Bias

    Applying a voltage across the photodiode to improve saturation limits and response times. Reverse bias is recommended for SXUV diodes in high-flux applications.

    Applying a voltage across the photodiode to improve saturation limits and response times. Reverse bias is recommended for SXUV diodes in high-flux applications.

    Related: SXUV photodiodes from Opto Diode.

  • Reverse Bias Operation

    Applying a reverse voltage to a photodiode to increase its response speed and reduce capacitance, especially in high-frequency applications.

    Applying a reverse voltage to a photodiode to increase its response speed and reduce capacitance, especially in high-frequency applications.

  • RGB and RGBA LEDs

    Combine red, green, blue, and amber LED chips to produce white light with high CRI, ideal for applications requiring accurate color rendering.

    Combine red, green, blue, and amber LED chips to produce white light with high CRI, ideal for applications requiring accurate color rendering.

    Related: IR emitters and LEDs from Opto Diode.

  • Rise Time, Fall Time (tr, tf) Seconds

    Rise Time (tr): The time required for the detector output to rise from 10% to 90% of its maximum signal.

    Fall Time (tf): The time required for the detector output to fall from 90% to 10% of its maximum signal.

    <b>Rise Time (tr):</b> The time required for the detector output to rise from 10% to 90% of its maximum signal.

    <b>Fall Time (tf):</b> The time required for the detector output to fall from 90% to 10% of its maximum signal.

  • RMS Noise (N) Volts RMS or Amps RMS

    The electrical output of a detector without any incident radiation, influenced by factors like detector area, background temperature, and bias.

    The electrical output of a detector without any incident radiation, influenced by factors like detector area, background temperature, and bias.

  • RMS Signal (S) Volts RMS or Amps RMS

    The electrical output of the detector caused by incident signal radiation.

    The electrical output of the detector caused by incident signal radiation.

  • Room Illumination Currents

    Currents generated by photodiodes exposed to visible light under ambient conditions. Coated photodiodes typically exhibit lower currents compared to uncoated ones.

    Currents generated by photodiodes exposed to visible light under ambient conditions. Coated photodiodes typically exhibit lower currents compared to uncoated ones.

  • Saturation

    A condition where the photodiode cannot handle additional photon flux, resulting in a plateau in output signal. Reverse bias mitigates saturation effects.

    A condition where the photodiode cannot handle additional photon flux, resulting in a plateau in output signal. Reverse bias mitigates saturation effects.

  • Shunt Resistance (Rsh)

    The resistance measured across the photodiode junction in the absence of illumination, influencing the noise characteristics and performance of the photodiode.

    The resistance measured across the photodiode junction in the absence of illumination, influencing the noise characteristics and performance of the photodiode.

  • Skin Therapy LEDs (410nm – 680nm)

    Violet and deep red LEDs used in medical treatments like skin rejuvenation and therapy.

    Violet and deep red LEDs used in medical treatments like skin rejuvenation and therapy.

    Related: IR emitters and LEDs from Opto Diode.

  • Solar Space Instrumentation

    AXUV photodiodes are used in missions like SOHO, SNOE, and SORCE for solar radiation measurement.

    AXUV photodiodes are used in missions like SOHO, SNOE, and SORCE for solar radiation measurement.

    Related: AXUV photodiodes from Opto Diode.

  • Soldering Instructions

    Photodiodes must be soldered following the guidelines in their specific data sheets. The soldering process must adhere to temperature limits and duration to avoid damage. Flux contamination must be cleaned with deionized water, alcohol, or acetone after soldering.

    Photodiodes must be soldered following the guidelines in their specific data sheets. The soldering process must adhere to temperature limits and duration to avoid damage. Flux contamination must be cleaned with deionized water, alcohol, or acetone after soldering.

  • Solid State Heat Pump

    Another term for a thermoelectric cooler, highlighting its ability to pump heat using solid-state components without moving parts.

    Another term for a thermoelectric cooler, highlighting its ability to pump heat using solid-state components without moving parts.

  • Spatial Responsivity Uniformity

    The consistency of a photodiode’s responsivity across its active area. SXUV-100 photodiodes exhibit uniformity within ±2%.

    The consistency of a photodiode's responsivity across its active area. SXUV-100 photodiodes exhibit uniformity within ±2%.

    Related: SXUV photodiodes from Opto Diode.

  • Spectral Output

    The distribution of light intensity across different wavelengths. LEDs can be tailored to specific spectral outputs for precise applications.

    The distribution of light intensity across different wavelengths. LEDs can be tailored to specific spectral outputs for precise applications.

    Related: IR emitters and LEDs from Opto Diode.

  • Spectral Response

    The sensitivity of a photodetector as a function of wavelength, showing how effectively it can detect different wavelengths of light.

    The sensitivity of a photodetector as a function of wavelength, showing how effectively it can detect different wavelengths of light.

  • Spectral Selectivity

    The ability of photodiodes to respond selectively to specific wavelengths, enhanced by applying thin-film filters.

    The ability of photodiodes to respond selectively to specific wavelengths, enhanced by applying thin-film filters.

  • Spectral Uniformity

    The consistency of photodiode responsivity across its active area. AXUV photodiodes have uniformity better than ±0.1% at 110 eV.

    The consistency of photodiode responsivity across its active area. AXUV photodiodes have uniformity better than ±0.1% at 110 eV.

    Related: AXUV photodiodes from Opto Diode.

  • Stopping Power

    The rate at which ions lose energy in the detector material, determined by electronic and nuclear interactions.

    The rate at which ions lose energy in the detector material, determined by electronic and nuclear interactions.

  • Sunlight CRI

    Natural sunlight has a CRI of 100, representing perfect color rendering.

    Natural sunlight has a CRI of 100, representing perfect color rendering.

  • Surface Contamination

    Deposits like carbon or oxidation on the photodiode surface that alter the responsivity and effective transmittance of the coatings.

    Deposits like carbon or oxidation on the photodiode surface that alter the responsivity and effective transmittance of the coatings.

  • Surface Layer Absorption

    Photon energy absorbed within the silicon dioxide surface layer, which affects responsivity. Shorter wavelengths tend to deposit energy deeper than longer wavelengths.

    Photon energy absorbed within the silicon dioxide surface layer, which affects responsivity. Shorter wavelengths tend to deposit energy deeper than longer wavelengths.

  • Surface Oxide Absorption

    The phenomenon where the surface oxide layer absorbs incident photons, contributing to responsivity calculations. AXUV photodiodes feature optimized oxide thickness for enhanced performance.

    The phenomenon where the surface oxide layer absorbs incident photons, contributing to responsivity calculations. AXUV photodiodes feature optimized oxide thickness for enhanced performance.

    Related: AXUV photodiodes from Opto Diode.

  • Surface Recombination

    A process where carriers recombine at the photodiode’s surface, reducing responsivity. Increased temperature may exacerbate surface recombination, decreasing responsivity by 0.1% per °C.

    A process where carriers recombine at the photodiode's surface, reducing responsivity. Increased temperature may exacerbate surface recombination, decreasing responsivity by 0.1% per °C.

  • Synchrotron Beam Monitoring

    AXUV photodiodes are used in synchrotron facilities for intensity monitoring and beam position sensing due to their stability and accuracy.

    AXUV photodiodes are used in synchrotron facilities for intensity monitoring and beam position sensing due to their stability and accuracy.

    Related: AXUV photodiodes from Opto Diode.

  • Synchrotron Radiation

    A highly polarized and intense radiation source used for calibrating and characterizing photodiodes with multilayer coatings.

    A highly polarized and intense radiation source used for calibrating and characterizing photodiodes with multilayer coatings.

  • TE Cooling (Thermoelectric Cooling)

    A method of cooling photodetectors using the Peltier effect to maintain a stable temperature, enhancing performance by reducing thermal noise.

    A method of cooling photodetectors using the Peltier effect to maintain a stable temperature, enhancing performance by reducing thermal noise.

  • Temperature Compensation

    Adjustments made to stabilize LED color output over varying ambient temperatures.

    Adjustments made to stabilize LED color output over varying ambient temperatures.

    Related: IR emitters and LEDs from Opto Diode.

  • Temperature Controller/Power Supply

    A temperature controller or power supply is necessary to stabilize and control the operating temperature of a TE-cooled detector over a range of ambient system temperatures.

    A temperature controller or power supply is necessary to stabilize and control the operating temperature of a TE-cooled detector over a range of ambient system temperatures.

  • Temperature Dependence

    The responsivity and shunt resistance of SXUV photodiodes are affected by temperature. For example, responsivity decreases by 0.1% per °C, and shunt resistance decreases by a factor of 2 for every 6 °C increase.

    The responsivity and shunt resistance of SXUV photodiodes are affected by temperature. For example, responsivity decreases by 0.1% per °C, and shunt resistance decreases by a factor of 2 for every 6 °C increase.

    Related: SXUV photodiodes from Opto Diode.

  • Thermal Coefficient of Expansion (TCE)

    Differences in TCE between wire bonds and epoxy can cause damage under strong thermal changes, like rapid heating or cooling.

    Differences in TCE between wire bonds and epoxy can cause damage under strong thermal changes, like rapid heating or cooling.

  • Thermal Compound

    A paste-like substance applied between the detector package and heatsink to fill surface irregularities and improve thermal conductivity.

    A paste-like substance applied between the detector package and heatsink to fill surface irregularities and improve thermal conductivity.

  • Thermal Nitridation

    A process used to stabilize the surface layer of AXUV photodiodes, enhancing their performance and durability under extreme conditions.

    A process used to stabilize the surface layer of AXUV photodiodes, enhancing their performance and durability under extreme conditions.

    Related: AXUV photodiodes from Opto Diode.

  • Thermal Pad

    A solid interface material used as an alternative to thermal compound, offering increased durability and reduced thermal resistance over time.

    A solid interface material used as an alternative to thermal compound, offering increased durability and reduced thermal resistance over time.

  • Thermal Parameters

    Specifications that define the operating and storage temperature ranges for photodiodes, ensuring optimal performance and longevity.

    Specifications that define the operating and storage temperature ranges for photodiodes, ensuring optimal performance and longevity.

  • Thermal Path

    The route through which heat is conducted from the detector to the heatsink and ultimately dissipated into the atmosphere.

    The route through which heat is conducted from the detector to the heatsink and ultimately dissipated into the atmosphere.

  • Thermal Resistance

    The opposition to heat flow in the thermal path. Minimizing thermal resistance is critical for optimal detector and cooler performance.

    The opposition to heat flow in the thermal path. Minimizing thermal resistance is critical for optimal detector and cooler performance.

  • Thermistor

    A temperature-sensitive resistor used in control electronics to provide feedback for regulating the thermoelectric cooler’s input power and maintaining a stable temperature.

    A temperature-sensitive resistor used in control electronics to provide feedback for regulating the thermoelectric cooler’s input power and maintaining a stable temperature.

  • Thin Silicon Dioxide Window

    A 3-7 nm thick protective layer on AXUV photodiodes that ensures high quantum efficiency for low-energy photons and particles.

    A 3-7 nm thick protective layer on AXUV photodiodes that ensures high quantum efficiency for low-energy photons and particles.

    Related: AXUV photodiodes from Opto Diode.

  • Thin Silicon Layer

    A reduced silicon layer thickness in photodiodes, enabling improved rejection of X-ray radiation.

    A reduced silicon layer thickness in photodiodes, enabling improved rejection of X-ray radiation.

  • Ti/Mo/C Coating

    A specific multilayer coating composed of titanium, molybdenum, and carbon, designed for enhanced transmittance in the soft X-ray region.

    A specific multilayer coating composed of titanium, molybdenum, and carbon, designed for enhanced transmittance in the soft X-ray region.

  • Time Constant (τ) Seconds

    The detector’s speed of response to a square wave pulse of radiation.

    The detector’s speed of response to a square wave pulse of radiation.

  • Traffic Signal Lights

    LEDs provide consistent color and energy savings, with green, amber, and red LEDs commonly used.

    LEDs provide consistent color and energy savings, with green, amber, and red LEDs commonly used.

    Related: IR emitters and LEDs from Opto Diode.

  • Transmission Calculations

    Simulations using tools like SRIM to estimate energy loss in the passivation layer of photodiodes.

    Simulations using tools like SRIM to estimate energy loss in the passivation layer of photodiodes.

  • Transmission Mode Operation

    Some AXUV photodiodes, like the AXUV36, allow continuous intensity monitoring in transmission mode for X-ray beams.

    Some AXUV photodiodes, like the AXUV36, allow continuous intensity monitoring in transmission mode for X-ray beams.

    Related: AXUV photodiodes from Opto Diode.

  • Transmission Profiles

    The percentage of light transmitted through the multilayer coating on a photodiode, affecting its detection efficiency for specific wavelengths and polarization states.

    The percentage of light transmitted through the multilayer coating on a photodiode, affecting its detection efficiency for specific wavelengths and polarization states.

  • Trap Centers

    Defects in a photodiode that capture carriers, leading to non-linear response. UVG photodiodes eliminate trap center effects due to their superior design.

    Defects in a photodiode that capture carriers, leading to non-linear response. UVG photodiodes eliminate trap center effects due to their superior design.

    Related: UVG photodiodes from Opto Diode.

  • Ultraviolet (UV) Radiometry

    The measurement of UV radiation intensity, often conducted using AXUV photodiodes due to their stability and precision.

    The measurement of UV radiation intensity, often conducted using AXUV photodiodes due to their stability and precision.

    Related: AXUV photodiodes from Opto Diode.

  • Ultraviolet (UV) Stability

    SXUV photodiodes are resistant to UV-induced degradation, even after prolonged exposure to high-intensity radiation, such as 193 nm excimer laser pulses.

    SXUV photodiodes are resistant to UV-induced degradation, even after prolonged exposure to high-intensity radiation, such as 193 nm excimer laser pulses.

    Related: SXUV photodiodes from Opto Diode.

  • Ultraviolet LEDs (320nm – 360nm)

    LEDs used in industrial curing and biomedical applications. Fabricated using GaN/AlGaN materials, with ongoing developments for higher efficiency in shorter wavelengths.

    LEDs used in industrial curing and biomedical applications. Fabricated using GaN/AlGaN materials, with ongoing developments for higher efficiency in shorter wavelengths.

    Related: IR emitters and LEDs from Opto Diode.

  • Uniformity Testing

    Assessing the uniformity of photodiode response across the active area to ensure reliable measurements in applications like reflectometry.

    Assessing the uniformity of photodiode response across the active area to ensure reliable measurements in applications like reflectometry.

  • UV Stability

    UVG photodiodes maintain consistent performance after exposure to intense ultraviolet radiation, such as 20 mW/cm² of 254 nm light for two weeks.

    UVG photodiodes maintain consistent performance after exposure to intense ultraviolet radiation, such as 20 mW/cm² of 254 nm light for two weeks.

    Related: UVG photodiodes from Opto Diode.

  • UV Transmission Window

    An optional feature for UVG photodiodes, allowing operation in environments where additional protection is needed. Materials include fused silica or magnesium fluoride.

    An optional feature for UVG photodiodes, allowing operation in environments where additional protection is needed. Materials include fused silica or magnesium fluoride.

    Related: UVG photodiodes from Opto Diode.

  • Wavelength

    The color of light emitted by an LED, measured in nanometers (nm). Specific wavelengths are tailored for applications like medical treatments, illumination, and signaling.

    The color of light emitted by an LED, measured in nanometers (nm). Specific wavelengths are tailored for applications like medical treatments, illumination, and signaling.

    Related: IR emitters and LEDs from Opto Diode.

  • Wavelength Dependence

    Variations in photodiode performance across different wavelengths, influenced by coating materials and optical properties.

    Variations in photodiode performance across different wavelengths, influenced by coating materials and optical properties.

  • Wavelength Range

    The spectral range of commercially available LEDs, spanning from UV (320nm) to near-infrared (950nm). Specific ranges are determined by semiconductor materials and market demand.

    The spectral range of commercially available LEDs, spanning from UV (320nm) to near-infrared (950nm). Specific ranges are determined by semiconductor materials and market demand.

    Related: IR emitters and LEDs from Opto Diode.

  • White LEDs

    Available as phosphor-pumped or RGB/RGBA types. RGB/RGBA LEDs provide superior color rendering compared to phosphor-pumped LEDs.

    Available as phosphor-pumped or RGB/RGBA types. RGB/RGBA LEDs provide superior color rendering compared to phosphor-pumped LEDs.

    Related: IR emitters and LEDs from Opto Diode.

  • White LEDs

    LEDs that emit white light through phosphor conversion or a combination of red, green, and blue emitters.

    LEDs that emit white light through phosphor conversion or a combination of red, green, and blue emitters.

    Related: IR emitters and LEDs from Opto Diode.

  • Windowless Design

    UVG photodiodes are designed without a protective window, reducing interference and enhancing quantum efficiency. They can be provided with optional UV-transmitting windows for specific applications.

    UVG photodiodes are designed without a protective window, reducing interference and enhancing quantum efficiency. They can be provided with optional UV-transmitting windows for specific applications.

    Related: UVG photodiodes from Opto Diode.

  • XUV Spectral Range

    The range of extreme ultraviolet radiation where AXUV photodiodes excel, offering high quantum efficiency and stability.

    The range of extreme ultraviolet radiation where AXUV photodiodes excel, offering high quantum efficiency and stability.

    Related: AXUV photodiodes from Opto Diode.

  • Zero-Order Beam

    A beam of monochromatic radiation used during photodiode characterization. Produces measurable photocurrents used to determine coating transmittance.

    A beam of monochromatic radiation used during photodiode characterization. Produces measurable photocurrents used to determine coating transmittance.

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