Development of 1.6 μm DIAL using an OPG/OPA transmitter for measuring atmospheric CO₂ concentration profiles.

An experiment for the measurement of atmospheric CO₂ vertical profiles up to a 7 km altitude was successfully conducted using a 1.6 μm ground-based differential absorption Lidar developed by Tokyo Metropolitan University. To achieve a high pulse repetition rate, large power output, and high frequency stabilization, we developed a new 1.6 μm Lidar system using an optical parametric generator (OPG) transmitter. Unlike the previous system's transmitter, OPG does not need a resonator. We amplified its output with two optical parametric amplifiers. We validated our system against an in situ sensor and found the difference between their CO₂ concentration measurements to be 0.06 ppm.