2020 Volume 63 Issue 2 Pages 42-49
Three-dimensional (3D) image sensors have many applications, including enabling autonomous vehicles to avoid obstacles and providing guidance, navigation, and control for spacecraft immediately before landing on a celestial body. Flash LIDAR is a system that can acquire a 3D image by emitting a diffuse pulsed laser beam, and hence is suitable for both obstacle detection and terrain measurement. In the 3D image sensors used for Flash LIDAR, a photosensor array and time measurement integrated circuit are vertically bonded. Here, we report the results of a detailed evaluation of the principles, functions, sensitivity, and time measurement accuracy of a prototype 1-k pixel (32 × 32 pixels) 3D image sensor based on a multi-pixel photon counting avalanche photodiode. By counting photons, a 3D image sensor is realized that has both high sensitivity and the ability to measure light intensity.