Glossary

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

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

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

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.

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.

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

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

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

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

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

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

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

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

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.

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

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

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

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

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

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

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

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.

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

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.

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.

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

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

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

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.

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

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

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

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.

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

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

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

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

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

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.

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

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

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.

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

The percentage of photogenerated carriers successfully collected by the photodiode.

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

A measure of detector response speed.

The maximum wavelength of light that a photodiode can detect.

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

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

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.

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

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

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

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

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

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.

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

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

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

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.

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).

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

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 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.

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

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.

The non-active distance between detectors in an array.

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

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

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

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

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

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

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

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

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

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

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

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

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

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.

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

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.

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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 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.

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

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

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

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

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

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.

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

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

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

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

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.

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

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

The value of bias voltage which yields maximum signal.

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

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

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

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.

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

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

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

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

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.

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

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

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.

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

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.

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

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

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

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 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).

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. Common for general illumination.

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).

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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.

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

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.

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

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

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

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

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

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

Used in traffic signal lights and RGB white light systems.

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

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

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

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

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

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

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

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.

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.

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

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

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

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.

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

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

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

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

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

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

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

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.

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

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

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

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

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

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

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

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

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

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

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

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.

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

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

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

Adjustments made to stabilize LED color output over varying ambient 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.

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.

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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.

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

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

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.

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

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