Abstract

In the DIAL technique, the water vapor concentration profile is determined by analyzing the lidar backscatter signals for laser wavelengths tuned "on" and "off" a water vapor absorption line. Desired characteristics of the on-line transmitted laser beam include: pulse energy ≥100 mJ, high-resolution, continuous tuning capability (uncertainty < 0.25 pm), good spectral stability (jitter <0.5 pm about the mean), and high spectral purity (>99%).¹ The off-line laser, whose spectral requirements are much less stringent, is generally detuned less than 100 pm away from the water vapor line.

© 1997 Optical Society of America