Development of a differential-absorption lidar system for measurement of atmospheric atomic mercury by use of the third harmonic of an LDS-dye laser

摘要

A differential-absorption lidar system that uses a long-life transmitter for monitoring of atomic-mercury concentrations in the atmosphere has been developed. The third harmonic of a tunable dye laser with LDS 765 dye pumped by the second harmonic of a Nd:YAG laser was used as the emitted beam from the transmitter. By use of this system, atmospheric concentrations of atomic mercury of less than 0.4 part in 10~(12) were measured. The time trend of the measured concentration agreed with that obtained by a conventional gold amalgamation method combined with atomic absorption spectroscopy on the ground.