雙縱模雙頻激光干涉儀的非線性對測量精度的影響

楊春生[1,2] 張濤[1] 成俊康[1] 劉國棟[1][1]四川大學制造科學與工程學院,成都610065 [2]中國測試技術研究院,成都610021摘　要:對具有特殊后續(xù)電信號處理系統的雙縱模雙頻激光干涉儀的非線性誤差進行了研究。根據理論分析推導出了存在非線性時輸出信號的表達式，并據此給出了非線性誤差的表現形式是使混頻輸出信號產生漂移起伏，主要影響因素是偏振分光鏡分光偏振度及光路調整理想程度。根據分光偏振度可計算信號最大漂移幅度及其帶來的測量誤差，計算出的漂移幅度值與實際觀測值相近，該值可作為判斷光路調整精度的一個標準，也是確定后續(xù)信號處理環(huán)節(jié)（細分辨向計數）中最大細分數的依據。[著者文摘]

Influence of nonlinearity on measuring precision of dual-frequency laser interferometer with two longitudinal modesYang Chun-sheng, Zhang Tao, Cheng Jun-kang, Liu Guo-dong 1. School of Manufacturing Science and Engineering, Sichuan University, Chengdu 610065, China; 2. National Institute of Measurement and Testing Technology, Chengdu 610021, ChinaAbstract:The nonlinearity error of the dual-frequency laser interferometer with two longitudinal modes and special subsequent electrical signal processing system was studied. The expressions for the output signal pair were desired based on the theoretical analysis when the nonlinearity exised. From the above it was given that the nonlinearity makes the frequency-mixing output signals shift and undulate, and its main factors are the perfection degree of the optical system adjustment and the polarization splitting degree of the polanzation beam splitter. The maximum signal shift amplitude was close to that observed on oscillograph and it could be used to estimate the perfection degree of the optical system adjustment and determine the maximum interpolation number in the subsequent signal processing stage.[著者文摘]

Key words:technology of instrument and meter;longitudinal mode; dual-frequency laser interferometer; nonlinearity; shift; polarization splitting degree