Experimental evaluation of InGaAs photodetectors for two-micron coherent lidars

Summary form only given. In view of growing interest in eye-safe, solid-state coherent lidars using thulium- and holmium-based lasers, it has become necessary to investigate the properties of wideband two-micron detection devices and evaluate their performance as heterodyne detectors. For this purpose, a detector measurement system has been developed that is capable of measuring all the necessary detector parameters for optimal designs of optical heterodyne receivers and predicting their sensitivities. Several commercially available InGaAs IR photodetectors with different active area sizes have been characterized and their optimum operating and electronic interface parameters have been determined as a function of the signal IF bandwidth requirement.