Advanced SWIR APDs for multimode applications

Abstract

Recent short-wave infrared (SWIR) sensors have demonstrated in-pixel multimode capabilities. One of the additional modes is range finding. High resolution range finding is increasingly becoming vital functionality in high precision targeting and imaging systems. Highly precise and accurate range-to-target information is essential for many modern commercial and military applications. With the recent advances in LiDAR (Light Detection and Ranging) technology, range measurement accuracies as low as a centimeter at kilometer ranges. Sensors Unlimited Inc. (SUI), a Raytheon Technologies (RTX) Company, has been developing these multimode sensors using traditional PIN-based InGaAs detector technology. However, the capability of these sensors has been extended through the introduction of Avalanche Photodetector (APD) InGaAs sensors. This APD technology has been developed onshore to better serve the onshore community requiring simultaneous laser tracking, ranging, and imaging applications. In this work, SUI offers an update on previously presented, PDA-specific development, most specifically related to the advancement of Geiger Mode Avalanche Photodetectors (GMAPD). SUI’s APD technology is in direct response to the challenging SWaP and NEI performance requirements of active imaging and tracking applications. This update includes 2D and 3D TCAD simulation results with a comparison with measured performance results. Finally, initial results related to the advanced development of Geiger Mode Avalanche Photodetectors (GMAPD) themselves as well as supporting electronics is given. The revitalization of SUI’s APD development is a direct response to the challenging SWaP and longer-range with higher accuracy performance requirements of active imaging applications. SUI’s most recent APD design improvements facilitates greater signal to noise ratio at the pixel, which subsequently enables a supporting ROIC pixel design with improved performance.