双波长单光栅纳米测量中激光器性能非理想的影响  

Effect of non-ideal performance of lasers in dual-wavelength single-grating nanometer measurement

作　　者：王国超[1] 颜树华[1] 周卫红[1] 牛正一[1] 谢学东[1] 

机构地区：[1]国防科学技术大学机电工程与自动化学院,湖南长沙410073

出　　处：《红外与激光工程》2011年第6期1119-1124,共6页Infrared and Laser Engineering

基　　金：国家自然科学基金(50875258)

摘　　要：阐述了双波长单光栅式大量程纳米级位移测量系统的基本原理,并对系统具有的量程大、精度高、稳定性好等特点进行了介绍。由于系统进行的是高精度纳米级的位移测量,必须考虑各种不利因素造成的误差影响,主要分析讨论了双频激光器性能非理想所造成的误差,包括波长不稳定造成的线性误差及椭圆极化偏振所造成的非线性误差。并在理论建模的基础上,导出了相应的误差表达式。最后通过仿真计算,指出波长不稳定造成的线性误差的极限值为2 nm,在非正交角为1.1°,渥拉斯顿棱镜的透过率Tx、Ty分别为0.85、1时,椭圆极化偏振所造成的非线性误差极值达到1.54 nm,并选取不同的非正交角及Tx、Ty对误差变化规律进行了研究分析。Principles of the dual-wavelength single grating nanometer displacement measurement system were presented,and its characteristics of long range,high precision and good stability were introduced.As a result of the nano-level high-precision displacement measurement,the errors caused by all sorts of adverse factors must be taken into account.The errors due to non-ideal performance of the dual-frequency laser were mainly discussed and analyzed,including linear errors caused by wavelength instability and non-linear errors caused by elliptic polarization of the laser.On the basis of theoretical modeling,the corresponding error formulas were derived as well.The simulation result shows that the limit value of linear errors caused by wavelength instability is 2 nm,and the limit value of nonlinear-errors caused by elliptic polarization is 1.54 nm on condition that Tx=0.85,Ty=1 of the WLS and the size of the non-orthogonal angle is 1.1°.Moreover,the law of the error change was analyzed and researched by choosing different values of Tx and Ty.

关 键 词：位移测量 光栅 外差干涉 波长不稳定 非正交角 

分 类 号：TH744.3[机械工程—光学工程]