A New Method of Anti-Jamming Ability Improvement for Michelson Interferometer
LI Yang-jun1, LIAN Su-jie2, SHI Jia1, GUO Ya-fei1, WANG Gao1
1. National Key Laboratory for Electronic Measurement Technology, Key Laboratory of Instrumentation Science & Dynamic Measurement, North University of China, Taiyuan 030051, China 2. Baicheng Ordnance Test Center, Baicheng 137001, China
Abstract：In order to improve anti-jamming capability of Michelson interferometer system, replace the traditional structure of the moving mirror scanning was replaced, an interference system based on electro-optic modulation of crystal refractive index was designed to achieve optical path scanning. The system modulated voltage signal on the variable refractive crystal, to generate cyclical changes, changed the refractive index to control optical path difference in the original optical path system. Using electronic scanning to replace of mechanical scanning, improved the system’s noise immunity was improved. In the electro-optic modulation process, computed the maximum optical path difference of the system was computed, and analyzed of the crystal thickness and crystal diffraction efficiency of the modulation process were analyzed. The simulation experiment shows that, with the modulation voltage range increasing, the available range of the optical path is also increased, and the system spectrum resolving power will also increase accordingly. Meanwhile, in the modulation process set the modulation range was set to make the energy of diffraction energy losses less than 10% of the total energy, so as to ensure a better signal to noise ratio. Experimental results show that, as the modulation voltage changes, interference fringes occurred continuously moved. When the voltage is further increased, the nonlinear error appears. After non-linear error correction for the system, spectrum resolution reached to 7.2 cm-1, slightly lower than the original system. But its anti-jamming capability is greatly enhanced, as in the absence of experimental platform for seismic conditions, conventional interferometer relative error is more than 20%, while the relative error of the system is less than 5%, in line with the design requirements. It was proved that the anti-jamming capability of the system was enhanced greatly, when the static electro-optical modulation was used.
Key words：Michelson interferometer;Refractive index modulation;Anti-jamming ability;Spectrum resolution
李仰军1，莲素杰2，石 佳1，郭亚飞1，王 高1 . 一种提高迈克尔逊干涉系统抗干扰能力的新方法 [J]. 光谱学与光谱分析, 2014, 34(05): 1425-1428.
LI Yang-jun1, LIAN Su-jie2, SHI Jia1, GUO Ya-fei1, WANG Gao1 . A New Method of Anti-Jamming Ability Improvement for Michelson Interferometer. SPECTROSCOPY AND SPECTRAL ANALYSIS, 2014, 34(05): 1425-1428.
