Acta Optica Sinica, Volume. 40, Issue 17, 1706002(2020)
Quasi Single Mode Design and Implementation of Doppler Lidar Frequency Discrimination System Based on Multimode Fiber Mach-Zehnder Interferometer
The Doppler lidar has been widely used in the detection of atmospheric wind field. An optical fiber Mach-Zehnder interferometer (MZI) used as a new frequency discrimination system for the Doppler lidar, has the advantages of small size, light weight, and high stability. To address the problems of serious energy coupling loss and low coupling efficiency when the commonly used single-mode fiber MZI is directly coupled with the multimode fiber of the telescope receiving system, the multimode fiber MZI is proposed as a frequency discrimination system to improve the coupling efficiency and increase the energy and detection height. In order to solve the problem of interference quality degradation caused by the multimode fiber MZI, the quasi single mode output of the multimode fiber is realized by adjusting the incident angle and disturbing mode. Theoretical calculation results show that the incident angle of the quasi single mode output of the multimode fiber used in the experiment is 0.8° and the diameter of the disturbed mode is 2.2 cm, which are experimentally verified. Through the simulation and comparative analysis of the signal-to-noise ratio of Doppler lidar wind measurement, we find that the multimode fiber MZI used as a frequency discriminator will effectively improve the system detection performance.
Get Citation
Copy Citation Text
Li Wang, Yang Chen, Jianping Suo, Rui Pan, Dong Wang, Fei Gao, Dengxin Hua. Quasi Single Mode Design and Implementation of Doppler Lidar Frequency Discrimination System Based on Multimode Fiber Mach-Zehnder Interferometer[J]. Acta Optica Sinica, 2020, 40(17): 1706002
Category: Fiber Optics and Optical Communications
Received: Apr. 23, 2020
Accepted: May. 29, 2020
Published Online: Aug. 25, 2020
The Author Email: Hua Dengxin (dengxinhua@xaut.edu.cn)