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.
The APD12703 series photodetector uses a 3mm diameter large target APD photodetector with very high gain and UV enhancement at 355nm, very suitable for fluorescence detection and other scenarios.
The spatial resolution is related to your optical pulse parameter setting, which is set according to the monitoring length of the fiber optic cable. 40km distance we can achieve 5m spatial resolution.