激光功率变化引起的非线性误差对纳米测量精度的影响

Effect of the Nonlinear Error of Laser Power on Nanometer Measurement in a Heterodyne Interferometer

拍频干涉法可用于纳米、亚纳米级精度的位移测量，其测量不确定度主要取决于单位频差─—位移当量的非线性。本文对影响非线性的因素进行了试验分析和理论计算，结果表明，非线性范围为０．０７～１．５ｎｍ。

A heterodyne interferometer may be used in the displacement measurement with an accuracy of nanometer or subnanometer order. The accuracy mainly depends on the nonlinearity of the ratio of displacement to frequency difference. The factors of causing nonlinearity are discussed and calculated in this paper. They may cause a nonlinear error in the range of 0.07￣1.5nm.