Tunable, UV Solid-State Lidar for Measurement of Nitric Oxide Distribution

A solid-state differential absorption lidar (DIAL) system was developed for nitric oxide monitoring. The ultraviolet (UV) light was generated through second-harmonic generation, subsequent to the sum-frequency mixing of the pulses from a Ti:sapphire laser, pumped by a frequency-doubled Nd:YAG laser, and from the fundamental of another Nd:YAG laser. The output pulse energy achieved in this way was 4 mJ at 226.8 nm with 2 pm linewidth. This DIAL system made it possible to measure the spatial distribution of nitric oxide emitted from a diesel engine installed at a distance of 130 m from the lidar for demonstration of stack plume, with the detection accuracy of 0.065 ppm with a range resolution of 10 m. We also measured the background nitric oxide of the order of 10 ppb in the urban atmosphere.