The APD modules are based on low-noise avalanche photodiodes made of InGaAs with a built-in pre-amplifier and high voltage supply.A temperature compensation function allows the APD to be operated at constant gain across a wide operating temperature range.
The PD610 is a photodetector with amplification circuitry for free-space optical systems. The unit includes a photodiode, transimpedance amplifier, and RF connector packaged in an aluminum housing.