Fiber-Laser-Based Water Vapor Differential Absorption Lidar System

72741S03-I The concentration and transport mechanism of water vapor in the atmospheric boundary layer are important parameters in the modeling of climatic processes and weather forecasting. Understanding these mechanisms will require the continuous monitoring of vertical water vapor profiles, and differential absorption lidars (DIAL) are well suited for this task. Although the DIAL technique has been well established, the associated instrumentation is research-oriented and expensive; therefore, it is not suitable for routine measurements. This project will adapt fiber lasers and fiber amplifiers, based on recent advances in the optical telecommunications industry, to develop a compact, field-deployable lidar system. Phase I will develop a pulsed, narrow-line laser source at 1500 nm using fiber-based components such as fiber amplifiers and modulators. Water vapor absorption characteristics in the 1500 nm region will be evaluated to identify suitable water vapor lines for both on-line and off-line operating wavelengths. Finally, a fiber amplifier design for an optical receiver will be developed to complete the full DIAL system design. Commercial Applications and Other Benefits as described by awardee: An inexpensive, autonomous water vapor DIAL should allow the commercialization of a meteorological tool that provides valuable data for improved weather tracking and forecasting. The DIAL system also could be deployed at airports to monitor frontal passes causing local turbulence patterns.