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Abstract
It is a compact, eye-safe, coaxial Micropulse Lidar System, mainly for atmospheric aerosol and cloud profiling. A compact diode pumped frequency doubled Nd:YAG pulse laser is employed with high repetition rate (1KHz) and low pulse power (25 j) to obtain eye-safety through beam expanding. As a result, a high sensitive Avalanche Photo Diode (APD) photon counting detector is used to detect the very weak back-scattering signals. In order to avoid low energy efficiency of conventional coaxial lidar system (typically 55%), a specially designed micro-optical element (MOE) is designed. The MOE is used to shape the Gaussian laser beam into a hollow ring flattop beam profile before coupling into the telescope emitter, this will increase energy efficiency to a theoretically limit of 96%. This portable eye-safe mobile CMPL System can be applied for the full-time unattended routine measurement and vertical profiling of atmospheric aerosol concentration and cloud height. Apart from collaborating with the Environmental Protection Department of the HKSAR Government to measure the atmospheric aerosols in Hong Kong, the project team was also commissioned by the Macao Meteorological and Geophysical Bureau to develop a lidar system for monitoring the atmospheric aerosols in Macao.
Features
• Eye-safety for personnel near operation field
• Mono-static system design is employed to achieve a relatively simple and compact system for mobile measurement task and improvement in the complexity of data processing of current bi-static system
• A microoptical beamshaper for high energy efficiency and elimination of radiation damage of strong background upon high sensitive detector
Applications
• Atmospheric dynamics studies
• Environmental and pollution monitoring
• Climate modeling and prediction
Contact Information
Mr H Y Wong
Director, Technology Transfer Office
City University of Hong Kong
83 Tat Chee Avenue
Kowloon, Hong Kong
Tel : (852) 2788 8428
Fax : (852) 2788 9119
Email : hy.wong@cityu.edu.hk
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