The 2026 Optical Semiconductor Selection Guide puts CEL’s full optical lineup in one PDF. It covers LEDs, photodiodes, avalanche photodiodes (APDs), PD-TIA and APD-TIA receivers, phototransistors, 850 nm VCSELs and SWIR reflective sensors. Detector coverage runs from 200 nm (GaN UV sensors) to 1700 nm (InGaAs).
Each table lists wavelength, output power or responsivity, bandwidth or bit rate, and package, so you can narrow a part list before opening datasheets.
Download the Selection Guide (PDF)
What the Guide Covers
| Family | Spectral range | Examples from the guide |
|---|---|---|
| UV LEDs | 367 to 378 nm | KED373UH, KED365UH |
| Red and IR LEDs | 660 nm, 850 to 1650 nm | KED351RHD (660 nm), KEDE1652H (1650 nm) |
| Multi-wavelength LEDs | 660 nm with 880 or 940 nm | KED691DS3, KED530HDB |
| Parallel beam LEDs | 660 to 890 nm, 2 to 18 degree half angle | KED050-H23, KED358-H23 |
| GaN UV sensors | 200 to 320 nm | KPDU086SU27-H11Q, KPDU086SU31-H11Q |
| Si photodiodes | 400 to 1100 nm | KPD1801H, KPD30S |
| GaAs photodiodes | 650 to 880 nm, up to 4.0 GHz | KPDG008-H8 |
| InGaAs photodiodes | 900 to 1700 nm | KPDE086S-H8, KPDE300-H53 |
| Si and InGaAs APDs | 400 to 1000 nm, 900 to 1700 nm | KPDA020P-H8, KPDEA005-56F |
| PD-TIA and APD-TIA receivers | 650 to 880 nm (GaAs), 900 to 1700 nm (InGaAs) | KPDX10G-T, KPDXA10G-T |
| 850 nm VCSELs | 850 nm, 4 GHz bandwidth | KLD085VC-H32, KLD085VC-LTH32 |
| SWIR reflective sensors | 1300 to 1650 nm, plus 810 nm on dual parts | KPR15S6, KPR816DS6 |
Many photodiode and APD parts also appear with datasheets and distributor links on the Photodiodes page.
PD-TIA or APD-TIA
Both receiver types pair a detector with a transimpedance amplifier in one package. The choice comes down to how much optical power reaches the receiver.
| Bit rate | InGaAs PD-TIA sensitivity | InGaAs APD-TIA sensitivity |
|---|---|---|
| 10 Gbps | -19 dBm at 10.3 Gbps (KPDX10G) | -28 dBm (KPDXA10G) |
| 2.5 Gbps | -29 dBm (KPDX2GK) | -35 dBm (KPDXA2GK) |
| 1.25 Gbps | -32 dBm (KPDX1GK) | -38 dBm (KPDXA1GK) |
At 10 Gbps the APD-TIA receives about 9 dB less light. That margin pays for longer fiber, more connectors or a weaker source. The cost is bias. An APD needs a high reverse voltage, and its gain shifts with temperature, so the bias supply has to track it. If the PD-TIA meets your link budget, it is the simpler design.
Both come in pigtail and TO-can versions. The KPDXA10G-XMD adds an LC receptacle option. GaAs PD-TIA receivers cover 650 to 880 nm at 1.25 to 4.25 Gbps for short-wavelength links.
Matching Parts to Applications
Pulse Oximetry
Pulse oximeters compare red and infrared absorption through tissue. The KED691DS3 puts 660 nm and 940 nm emitters in one package, rated 5.5 mW red and 4.5 mW IR at 20 mA. A Si photodiode (400 to 1100 nm) covers both wavelengths on the receive side.
Photoelectric and Encoder Sensing
Through-beam and reflective object sensors pair an IR LED with a Si photodiode or phototransistor. For longer gaps or encoder disks, the parallel beam LEDs narrow the beam to half angles as small as 2 degrees, which puts more light on a small detector.
Smoke Detection
Scatter-type smoke detectors place an IR LED and a photodiode off-axis in a dark chamber. Smoke scatters light onto the detector and raises its current. Any of the 850 to 940 nm IR LEDs in the guide pairs with a Si photodiode for this.
Fiber and Free-Space Links
Use the table above for the receiver. On the transmit side, the KLD085VC-H32 VCSEL delivers 2.5 mW at 7 mA with 4 GHz bandwidth in a TO-can. The KLD085VC-LTH32 is the LC-TOSA version at 1 mW. 850 nm VCSELs are the usual source for short-reach multimode fiber.
Ranging and Proximity
Si APDs (400 to 1000 nm, 0.45 A/W at 850 nm with M=1) pair with 850 nm sources for time-of-flight distance sensing. Be realistic about range. The listed VCSELs are single emitters rated in milliwatts, suited to proximity, encoders and short-range sensing. Long-range automotive LiDAR emitters are not part of this guide.
NIR Material Analysis
SWIR reflective sensors put an LED and a photodiode side by side in one SMD package. Dual-wavelength parts pair an 810 nm reference with a SWIR line: the KPR816DS6 uses 810 and 1650 nm, the KPR815DS6 810 and 1550 nm. Comparing the two returns separates moisture, plastics and organic content in sorting and inline inspection.
Methane Sensing
Methane has an absorption band near 1650 nm. The KEDE1652H LED (1650 nm) with an InGaAs photodiode can measure it. CO2 is a different case. Its strong absorption band is near 4.3 µm, well past the 1700 nm limit of InGaAs, so CO2 NDIR sensors need detectors outside this lineup.
UV Monitoring
The GaN UV sensors respond from 200 to 290 nm (KPDU086SU27-H11Q, 0.095 A/W at 254 nm) or 200 to 320 nm (KPDU086SU31-H11Q, 0.075 A/W at 300 nm). That fits monitoring of 254 nm UV-C lamps. The UV LEDs at 365 to 378 nm suit fluorescence excitation and UV curing checks.
Reading the Tables
Check the test conditions before comparing parts. LED output is given at 20 mA or 50 mA depending on the family, and one IR LED is rated at 1 A. Photodiode bandwidth is quoted into 50 ohms at a stated reverse bias. Reflective sensor current is measured at 1 mm to the target. Compare at the same conditions, then confirm in the datasheet.
View the Full Selection Guide (PDF)
Need help pairing an emitter and detector? Use the form below and a CEL engineer will follow up.