A new concept for spatially resolved coherent detection with vertically illuminated photodetectors targeting ranging applications

Abstract

A novel approach for coherent detection with double-side vertically illuminated photodetectors is presented. Signal and local oscillator (LO) are injected collinearly from opposite sides of the photodetector chip. As a result, no optical combiners are required and the concept inherently provides angular selective detection, as the relative angle between signal and LO has a strong influence on the generated RF power. These properties can be exploited for developing compact, solid-state receiver modules in single-channel and arrayed configurations for different sensing and imaging applications, e.g., coherent light detection and ranging (LiDAR).