Receiver for Long-distance, Low-backscatter LiDAR

The NASA receiver is specifically designed for use in coherent LiDAR systems that leverage high-energy (i.e., > 1mJ) fiber laser transmitters. Within the receiver, an outgoing laser pulse from the high-energy laser transmitter is precisely manipulated using robust dielectric and coated optics including mirrors, waveplates, a beamsplitter, and a beam expander. These components appropriately condition and direct the high-energy light out of the instrument to the atmosphere for measurement. Lower energy atmospheric backscatter that returns to the system is captured, manipulated, and directed using several of the previously noted high-energy compatible bulk optics. The beam splitter redirects the return signal to mirrors and a waveplate ahead of a mode-matching component that couples the signal to a fiber optic cable that is routed to a 50/50 coupler photodetector. The receiver’s hybrid optic design capitalizes on the advantages of both high-energy bulk optics and fiber optics, resulting in order-of-magnitude enhancement in performance, enhanced functionality, and increased flexibility that make it ideal for long-distance or low-backscatter LiDAR applications. The related patent is now available to license. Please note that NASA does not manufacturer products itself for commercial sale. Researchers at the NASA Langley Research Center have developed a new coherent LiDAR (light detection and ranging) receiver compatible with high-energy fiber lasers. The hybrid receiver incorporates robust bulk optics (i.e., dielectric, coated optics) to handle high pulse energy where needed and fiber optics where damage tolerance is not critical. Commercially available receivers leveraging fiber optic components for metrology and remote sensing are not compatible lasers above ~100 micro-J. This restriction limits measurement distances to only a few kilometers out and to the lower atmosphere where aerosols are abundant. The new NASA design allows full advantage to be taken of novel high-energy pulsed laser technology to enable Doppler LiDAR measurements out to longer distances (> 10 km) and/or in conditions of lower aerosol backscatter for applications in markets including wind energy, aerospace & defense, and meteorology & environmental sensing.