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 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 is generally detuned less than 100 pm away from the water vapor line. Its spectral requirements are much less stringent.

© 1995 Optical Society of America