Lidar Technology Based on Fiber System and its Application

Xuewu Cheng,Yuan Xia,Xin Lin,Yong Yang,Yulian Yang,Faquan Li,Linmei Liu,D Liu,Y Wu,B Gross,F Moshary,Y Wang

doi:10.1051/epjconf/202023707019

Xuewu Cheng, Yuan Xia + Show 10 more

Open Access

https://doi.org/10.1051/epjconf/202023707019

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Abstract

The sodium atom existed in the metal layer of the earth’s atmosphere has a high atomic number density and a large scattering cross section. Sodium layer can act as a good tracer for atmospheric detection in the middle and lower-thermosphere (MLT) region. The sodium fluorescence lidar uses ultrashort pulsed laser to excite sodium atoms, which enabling simultaneous detection of wind and temperature in the middle and upper atmosphere. This paper reports on the development of sodium fluorescence laser radar in recent years, especially the integration of fiber-coupled optical switches and fiber-coupled acousto-optic frequency modulation technologies, which greatly improved the stability and reliability of lidar system and reduced the maintenance of lidar operation, laying a good foundation for the application of lidar observations under harsh environments. This technology has been applied to the sodium wind/temperature lidar in Yangbajing, Tibet and has been running stably for a long time.

Highlights

A layer of metal atoms exists at a height of 80-120 km of the earth's atmosphere
In the late 1990s, ultra-narrow bandwidth optical filtering technology was applied to the sodium lidar receiver, which enabling the full diurnal observation capability of sodium lidar permitting sodium layer wind and temperature measurement under sunlit conditions [6]
In the early studies of sodium wind temperature lidar, in order to realize the threewavelength laser emission for simultaneous wind and temperature measurement, a ring-cavity dye laser, a free-space acousto-optic frequency modulation unit are usually used in the laser transmitter, so the optical path of the laser system is complex, and the adjustment and maintenance are difficult, greatly limiting the lidar application

Summary

Introduction

A layer of metal atoms exists at a height of 80-120 km of the earth's atmosphere. The metal layer contains several kinds of metal atoms and ions, such as iron, sodium, potassium, calcium, and calcium ions [1]. In 1990s, the simultaneous detection of wind and temperature of the sodium layer was carried out using narrow linewidth laser and multi-wavelength transmitter

Results

Conclusion