论文部分内容阅读
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。
The principle of dual-wavelength single grating long-range nanometer displacement measurement system is expounded. And the characteristics of large-scale, high precision and good stability of the system are introduced. Due to the high accuracy of nanometer-scale displacement measurement, we must consider the error caused by various unfavorable factors. The errors caused by the non-ideal performance of dual-frequency laser are mainly analyzed and discussed, including the linear error caused by wavelength instability and the error of elliptic pole Nonlinear errors caused by polarization. Based on the theoretical modeling, the corresponding error expression is derived. Finally, the simulation calculation shows that the limit of linear error caused by wavelength instability is 2 nm. When the non-orthogonal angle is 1.1 °, the transmittances Tx and Ty of Wollaston prism are respectively 0.85 and 1, The polarization nonlinearity caused by the polarization extremum reaches 1.54 nm, and choose different non-orthogonal angle and Tx, Ty to study the variation of error.