PI at ArkLight proposes to implement photon counting detectors at near-IR (1-1.8 microns) and mid-IR (3-4 microns) with single photon sensitivity based on frequency up-conversion during Phase 2, representing an innovative Lidar technology for ASCENDS mission. By working with Prof. Ding at Lehigh University, PI will explore fundamental limits to quantum efficiencies for up-conversion detection at 1.57 microns. She will implement, characterize, and optimize single up-conversion device capable of detecting 1.57 microns and 1.27 microns. She plans to achieve detections of CO2 and O2 using implemented up-conversion device. She will investigate fundamental limits to noises for up-conversion detections. She will compare among PPLN, PPKTP, and PPLT as up-conversion media. She will expand detection wavelengths to cover ranges of 1-1.8 microns and 3-4 microns. She plans to introduce novel techniques for improving performances of up-conversion devices. She will investigate versatility of up-conversion devices under harsh environments. To achieve all these objectives, she has laid out a detailed work plan describing all the specific tasks necessary. Through optimizations, she will achieve the quantum efficiency of 50%, dark count rate of 50 Hz, bandwidth of GHz, electrical consumption of < 1 W, weight of < 1 lb, and dimension of 7x4x4 (all in inches).