Dual-wavelength locking technique for coherent 2-mu m differential absorption lidar applications

摘要

Y A dual-wavelength locking technique for coherent 2-mu m differential absorption lidar (DIAL) applications has been developed for simultaneously measuring water vapor (H2O) and radial wind velocity profiles. The two wavelengths for DIAL measurement were stabilized by sidebands of an electro-optic modulated laser, which was locked to the CO2 R30 absorption line. We selected wavelengths of 2050.550 and 2051.103 nm to minimize the effects of height-dependent temperature and pressure variations. The long-term wavelength stability of the two locked lasers of <0.2 pm, which corresponds to 14 MHz, was achieved. The DIAL instrument using the developed technique meets the requirement of measuring the H2O concentration with a systematic error <5% below an altitude of 5 km. (C) 2021 Optical Society of America