An avalanche photodiode buys you internal gain: bias the junction near breakdown and each photo-generated carrier triggers impact ionization, multiplying the signal before it reaches your amplifier. That is why an APD rather than a PIN photodiode is the right starting point when returns are photon-starved, pulses last nanoseconds, or the required bandwidth reaches into the gigahertz. Opto Diode, a division of ITW, designs and fabricates its avalanche photodiodes in Camarillo, California, and catalogs three: two silicon covering 400–1100 nm and one InGaAs covering 900–1700 nm, all in hermetically sealed TO-46 packages.
📄 ODD-APD-002 silicon APD datasheet (PDF)
Silicon or InGaAs? Start with your laser line
Spectral response settles the technology question first. Silicon responds from 400 nm to 1100 nm and runs out of absorption beyond roughly 1.1 µm; InGaAs covers the shortwave infrared from 900 nm to 1700 nm. In practice the source wavelength points at one part:
- 905 nm pulsed laser diode → ODD-APD-002, silicon
- 1064 nm Nd:YAG line → ODD-APD-003, silicon
- 1550 nm and the wider SWIR → ODD-APD-001, InGaAs
The two silicon parts share a band, an active area and a package, but they are not interchangeable: each is characterized at a different wavelength, and they sit in different voltage classes — the ODD-APD-002 breaks down between 100 V and 220 V, the ODD-APD-003 between 350 V and 460 V. Choose on operating wavelength, then design the bias supply around the part.
These are physically small detectors — a 500 µm circle (0.2 mm²) on the silicon parts, a 200 µm circle (0.031 mm²) on the InGaAs part. Small area is what holds typical capacitance to 1.2–2.5 pF and makes the speed figures possible, but it puts receiver optics and alignment tolerance on the critical path for delivered sensitivity.
Decoding the model numbers
Each device carries two identifiers that do not look alike: a descriptive model name/number, and the short ODD-APD-00x part number used on the datasheet. Read against the product category page and the datasheets, the model string carries the operating wavelength (1550, 905 or 1064), the technology (IGA for InGaAs, SI for silicon) and the package (T46 for TO-46).
| Model name/number | Part number | Technology & range | Characterized at | Active area | Datasheet |
|---|---|---|---|---|---|
| ODD-APD-020-905-SI-T46 | ODD-APD-002 | Silicon, 400–1100 nm | 905 nm | Φ0.5 mm, 0.2 mm² | |
| ODD-APD-020-1064-SI-T46 | ODD-APD-003 | Silicon, 400–1100 nm | 1064 nm | Φ0.5 mm, 0.2 mm² | |
| ODD-APD-003-1550-IGA-T46 | ODD-APD-001 | InGaAs, 900–1700 nm | 1550 nm | Φ0.2 mm, 0.031 mm² |
The numeric field inside the model string is not the part number. The InGaAs device is model ODD-APD-003-1550-IGA-T46 but part number ODD-APD-001 — while ODD-APD-003 is the part number of the silicon 1064 nm device. “ODD-APD-003” alone is therefore ambiguous, so give the full model string, or the part number with the wavelength, on every drawing, BOM line and quote request.
ODD-APD-002 — silicon APD for 905 nm
Model ODD-APD-020-905-SI-T46. The part for 905 nm pulsed-laser-diode systems: 0.55 A/W typical responsivity at unity gain, 0.5 ns typical rise time, and the lowest dark current of the three at 0.4 nA typical at a gain of 100 (each part specifies dark current at a different gain, so compare at the gain you will actually run).
| Parameter | Test conditions | Min | Typ | Max | Units |
|---|---|---|---|---|---|
| Active area | Φ0.5 mm | — | 0.2 | — | mm² |
| Spectral response | — | 400 to 1100 | nm | ||
| Responsivity | λ = 905 nm, M = 1 | 0.5 | 0.55 | — | A/W |
| VOP (gain = M) | λ = 905 nm, M = 100 | 95 | — | 209 | V |
| Dark current, Id | M = 100 | 0.2 | 0.4 | 1.0 | nA |
| Rise time, ts | λ = 905 nm, f = 1 MHz, RL = 50 Ω | — | 0.5 | 1.5 | ns |
| Capacitance, C | M = 100, f = 1 MHz | — | 1.2 | — | pF |
| Reverse breakdown voltage | IR = 10 µA | 100 | — | 220 | V |
| Temperature coefficient | IR = 10 µA, −40 °C to 85 °C | — | 0.9 | — | V/°C |
| Package | — | TO-46, hermetically sealed | — | ||
Ratings: APD supply voltage 0.95 × VBR maximum; operating temperature −45 °C to +85 °C; storage −45 °C to +100 °C; forward current 5 mA maximum; lead soldering 260 °C (0.080″ from case, 10 seconds).
Applications listed on the datasheet: time of flight (ToF) LiDAR systems; laser rangefinders; autonomous vehicle obstacle detection; safety scanners; free-space optical communications; optical speed measurements.
ODD-APD-003 — silicon APD for 1064 nm
Model ODD-APD-020-1064-SI-T46. Same silicon band and same 0.2 mm² area as the ODD-APD-002, but characterized at the 1064 nm Nd:YAG line, where silicon responsivity is inherently lower — 0.36 A/W typical at unity gain. It is the high-voltage device of the pair.
| Parameter | Test conditions | Min | Typ | Max | Units |
|---|---|---|---|---|---|
| Active area | Φ0.5 mm | — | 0.2 | — | mm² |
| Spectral response | — | 400 to 1100 | nm | ||
| Responsivity | λ = 1064 nm, M = 1 | 0.3 | 0.36 | — | A/W |
| VOP (gain = M) | λ = 1064 nm, M = 100 | 332 | — | 437 | V |
| Dark current, Id | M = 100 | — | 5.0 | 12.0 | nA |
| Response time, ts | λ = 1064 nm, f = 1 MHz, RL = 50 Ω | — | 2.0 | — | ns |
| Capacitance, C | M = 100, f = 1 MHz | — | 2.5 | 4.0 | pF |
| Reverse breakdown voltage, VBR | IR = 10 µA | 350 | — | 460 | V |
| Temperature coefficient | IR = 10 µA, −40 °C to 85 °C | — | 2.4 | 3.0 | V/°C |
| Package | — | TO-46, hermetically sealed | — | ||
Ratings: as the ODD-APD-002 above — supply 0.95 × VBR maximum; operating −45 °C to +85 °C; storage −45 °C to +100 °C; forward current 5 mA maximum; lead soldering 260 °C (0.080″ from case, 10 seconds).
Applications listed on the datasheet: target designators and laser spot trackers; remote sensing and LiDAR; industrial laser instrumentation; spaceborne LiDAR; optical communication at 1064 nm; scientific pulsed laser detection.
ODD-APD-001 — InGaAs APD for 1550 nm and the SWIR
Model ODD-APD-003-1550-IGA-T46. This is the bandwidth part: a −3 dB cut-off frequency of 0.6 GHz minimum and 1.25 GHz typical, specified at a gain of 10 into a 50 Ω load — quote those conditions with the figure, because the bandwidth depends on both. Unity-gain responsivity is 1.0 A/W typical at 1550 nm.
| Parameter | Test conditions | Min | Typ | Max | Units |
|---|---|---|---|---|---|
| Active area | Φ0.2 mm | — | 0.031 | — | mm² |
| Spectral response | — | 900 to 1700 | nm | ||
| Responsivity | λ = 1550 nm, M = 1 | 0.9 | 1.0 | — | A/W |
| VOP (gain = M) | λ = 1550 nm, M = 10 | 32 | — | 50 | V |
| VOP (gain = M) | λ = 1550 nm, M = 30 | 34 | — | 50 | V |
| Dark current, Id | M = 10 | — | 8.0 | 50.0 | nA |
| Dark current, Id | M = 30 | — | 8.0 | 50.0 | nA |
| −3 dB cut-off frequency (BW) | M = 10, RL = 50 Ω | 0.6 | 1.25 | — | GHz |
| Capacitance, C | M = 10, f = 1 MHz | — | 1.8 | 2.0 | pF |
| Temperature coefficient | IR = 10 µA, −55 °C to 85 °C | 0.07 | 0.11 | 0.15 | V/°C |
| Package | — | TO-46, hermetically sealed | — | ||
Ratings: APD supply voltage VBR maximum; operating temperature −40 °C to +85 °C; storage −55 °C to +125 °C; forward current 5 mA maximum; reverse current 3 mA maximum; lead soldering 260 °C (0.080″ from case, 10 seconds).
Applications listed on the datasheet: LiDAR (light detection and ranging); laser range finder; particle sizing; DNA sequencer; spectrometers; free space communication.
Bias, gain and temperature
Everything an APD gives you comes from operating close to breakdown, which is what makes bias the hard part of the receiver. Gain is a steep function of reverse voltage, so a stable, adjustable, temperature-aware supply belongs in the detector specification.
- There is no single operating voltage. Each datasheet specifies VOP against a stated gain, and as a min–max window rather than a number: 95–209 V for the ODD-APD-002 at M = 100, and 332–437 V for the ODD-APD-003 at M = 100. Expect to trim the bias per device to land on a target gain.
- Respect the supply ceiling. The silicon parts cap APD supply voltage at 0.95 × VBR; the InGaAs part caps it at VBR. Breakdown is published for the silicon devices (100–220 V and 350–460 V), but the ODD-APD-001 datasheet lists no VBR value in its characteristics table — confirm that ceiling before setting a supply limit.
- Compensate for temperature. The coefficients differ by an order of magnitude across the family: 0.11 V/°C typical for the InGaAs ODD-APD-001, 0.9 V/°C typical for the ODD-APD-002, and 2.4 V/°C typical (3.0 V/°C maximum) for the ODD-APD-003. Across a wide operating range the silicon parts need substantial correction to hold constant gain.
- Confirm the operating point for your gain. Each part’s VOP is specified at one headline gain condition; design the ODD-APD-002 supply around its M = 100 window, and verify any other operating point with Opto Diode’s applications engineers before committing a supply design.
Compare parts only at the gain you will use: dark current is quoted per gain condition — 0.4 nA typical at M = 100 for the ODD-APD-002 against 8.0 nA typical at M = 10 for the ODD-APD-001. With 1.2–2.5 pF typical capacitance across the family, the transimpedance stage and layout parasitics, not the diode, usually set the bandwidth you achieve.
Request a quote or talk through your receiver design
Send us your wavelength, pulse width, signal level and operating temperature range, and our applications engineers will help you choose between the silicon and InGaAs parts. Standard response to an online request is within 1–2 business days; direct orders must meet a $3,000 minimum.
Frequently Asked Questions
Should I choose a silicon or an InGaAs APD?
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Choose on wavelength. Opto Diode’s silicon APDs respond from 400 nm to 1100 nm, covering the 905 nm and 1064 nm laser lines; the InGaAs APD responds from 900 nm to 1700 nm for shortwave-infrared and 1550 nm work. Where the two bands overlap between 900 nm and 1100 nm, compare responsivity at your exact wavelength, the active area you can illuminate, and the bias voltage your design can supply.
What gain and bias voltage do these APDs operate at?
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There is no single answer, because operating voltage is specified against a gain condition and given as a range. The silicon ODD-APD-002 is specified at 95 V to 209 V for a gain of 100, the silicon ODD-APD-003 at 332 V to 437 V for a gain of 100, and the InGaAs ODD-APD-001 at 32 V to 50 V for a gain of 10. Supply voltage is limited to 0.95 times the reverse breakdown voltage on the silicon parts and to the reverse breakdown voltage on the InGaAs part, and the bias needs temperature compensation because breakdown drifts with temperature.
Which Opto Diode APD suits a 905 nm time-of-flight LiDAR?
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The ODD-APD-002, sold as model ODD-APD-020-905-SI-T46. It is the silicon device characterized at 905 nm, with 0.55 A/W typical responsivity at unity gain, 0.5 ns typical rise time into a 50 ohm load, and 0.4 nA typical dark current at a gain of 100. Its datasheet lists time of flight LiDAR systems, laser rangefinders, autonomous vehicle obstacle detection and safety scanners among its applications. The active area is a 500 micrometre circle, so plan the receiver optics accordingly.
Are these APDs hermetic, and can they be used in space or defense programs?
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All three ship in a hermetically sealed TO-46 package, and the ODD-APD-003 datasheet lists spaceborne LiDAR, target designators and laser spot trackers among its applications. The datasheets do not publish a space or military qualification level for these catalog parts. Opto Diode is ISO 9001:2015 certified and ITAR registered, and describes its high-reliability capability, including MIL-PRF-19500 screening to JANTX through JANS classes, separately from the catalog line, so specific screening requirements are quoted case by case.
Related
Specifications from the controlled Opto Diode datasheets: ODD-APD-001 Revision September 11, 2025; ODD-APD-002 and ODD-APD-003 Revision October 28, 2025. Reviewed and updated August 2026.