Ultrafast polarization independent optical aperture gating based on tunable photonic nanostructures

The primary objective of this proposed project is to develop an ultrafast speed, polarization independent optical aperture gating device, which can be conveniently integrated into a high sensitivity photodetector so that the daytime performance of the LIDAR can be dramatically improved. To realize this goal, we will develop an innovative tunable photonic nanostructure, which can offer following unprecedented performances: (1) polarization independent operation, (2) less than 10 ns switching speed, (3) less than < 2 dB insertion loss, (4) OD 4 or better extinction ratio, (5) high out-of-band rejection, (6) large field of view (+/- 40 deg), (7) 1 KHz or higher repetition rate, and (8) compact size and small footprint. At the phase I stage, we will conduct both the theoretical and the experimental feasibility study of the proposed approach. A bench-top experimental system (with an aperture size 1 square millimeter or larger) will be fabricated and tested. At the phase II stage, we will collaborate with a major commercial partner in this field to develop a ready-to-use gating prototype device with an aperture size (1 square centimeter or larger) and integrate this device into a high sensitivity photodetector (e.g., a photomultiplier tube).