Effect of Nonlinearity by the Amplitude Variation in coherent transmission in Laser Heterodyne Interferometric
To reduce the nonlinearity of nanometer measurement in laser heterodyne interferometric, the influence mechanics of the amplitude variation in coherent transmission upon nonlinearity must be confirmed. Based on the mechanics of nonlinearity, the models about how first-harmonic and second-harmonic nonlinearity caused by the amplitude variation in coherent transmission are proposed. The emulation result shows that different amplitude between measurement arm and reference arm increases the first-harmonic nonlinearity when laser beams nonorthogonality errors exist, but it doesnt change the relationship between nonlinearity and half wavelength. When the rotation angle error p of polarizing beam splitter (PBS) exists, amplitude variation only affects the first-harmonic nonlinearity. With a constant rotation angle of PBs β=4°, when the amplitude factor of measurement arm reduces from 1 to 0.6, the nonlinearity increases from 0.25 nm to 3.81 nm, and the nonlinearity is simple superposition of first-harmonic and second-harmonic. Theoretic analysis and emulation show that the reduction of amplitude variation in coherent transmission can reduce influence on nonlinearity.
H F Chen X M Ding Z Zhong Z L Xie H Yue
Institute of Ultra-precision Optoelectronic Instrument Engineering Harbin Institute of Technology, H Department of Communication Engineering, Harbin Institute of Technology, Harbin 150001, China
国际会议
第四届仪器科学与技术国际会议( 4th International Symposium on Instrumentation and Science and Tcchnology)
哈尔滨
英文
828-832
2006-08-08（万方平台首次上网日期，不代表论文的发表时间）