Description: A reduction in space and power requirements for each channel of a LiDAR system would allow for a system with significantly more channels and/or a system small enough to fly on CubeSat scale vehicles. The primary method by which the CoDLiR will accomplish this goal is the integration of feature extraction, digital processing, and bias control onto one single low-power chip. For a full-scale detector, multiple channels (up to 64) would be serviced by a single chip. NSL has extensive experience with single-photon detection with extremely high timing resolution through our work with HEP collider and astrophysics experiments. We are currently developing a range of application specific integrated circuits (ASICs) for DOE Office of High Energy Physics (HEP) projects that have channel counts ranging from 4 to 64 per ASIC, which could be modified for this task specifically. These system on chip (SoC) ASICs implement built-in digital signal processing (DSP) and control interfaces that can enable precise time of flight (ToF) measurements of back-scattered laser light pulses with low light for use in orbiting or aerial LiDAR applications. Conventional LiDAR requires hundreds of coincident detectable reflected photons for a ranging measurement. However, current LiDAR technologies for long-distance ranging, backscatter, or differential absorption are increasingly moving towards single-photon sensitive (SPS) technology. Single-photon detection has become increasingly attainable. Recent advances in SiPM technology have rendered them a desirable choice here as devices have become smaller (1mm x 1mm pixel size), faster (100ps rise time) more radiation hard while requiring only 30-90V bias voltages. Enhanced sensitivity to single reflected photons for long baseline measurements will reduce required laser system power and allow for more compact optical focusing lenses and mirrors.

Benefits: Future NASA scientific missions will require remote sensing equipment with lower power, smaller form factors, increased robustness, and higher sensitivities. Integration of LiDAR systems into a system-on-chip ASIC would achieve these goals and be of interest in numerous applications. Possible uses range from high-beam-count orbital LiDAR imaging systems to high-precision and low-power imaging sensors for planetary missions (e.g. surface mapping, altimetry and navigation assist).

A lightweight, power efficient, highly accurate LiDAR system is of interest to markets such as autonomous vehicles and aerial systems, which would benefit significantly from reduced power and size made possible by increased integration, lower return signal power requirements, and increased precision. Our product could be also utilized by various industries interested in orbital geospatial mapping.