Optical fiber detection modules immunity to high-power interference with photosensitive electronics

When the photodetector sensor is associated to incident peak power densities of the order of 1kW/cm
²
or more, in the silicon band of absorption (~500 to 1100nm), such as for laser range finding and LiDAR applications at 1064nm, the peripheral electronic components to the avalanche or PIN photodiode, such as transimpedance amplifier circuit elements, can be affected in an harmful manner due to their photosensitivity. It has long been known that integrated circuits composed of silicon devices are sensitive to light. In order to avoid this behavior, window photodetector sensors have to be associated to complex light shielding configurations for the electronic circuit. Using optical fiber coupling to the photodetector offers such shielding, if the optical fiber interface is designed properly.