光学倍频影响激光外差干涉测量精度的机理

为了同时提高激光外差干涉测量的分辨力和精度,必须深入分析光学倍频对激光外差干涉测量精度的影响机理。在此基础上,建立了光学倍频相位测量模型,从理论上证明,光学倍频能够实现对激光外差干涉信号的细分,提高测量分辨力。光学倍频改变非线性误差的相位而使非线性误差减小,但同时改变了激光干涉多普勒频移的v/c平方项,使得残余累计误差增大。仿真结果表明,光学N倍频使非线性误差减小到原来的1/N,但使残余累计误差增大N2倍。因此,光学倍频仅适用于低速测量的场合。

Mechanism of optical multiplication frequency effect on laser heterodyne interferometry

In order to improve the measurement accuracy of a laser heterodyne interferometer, it is necessary to analysis the effect mechanics of optical multiplication frequency on the measurement accuracy of laser heterodyne interferometry. A measurement model based on optical multiplication frequency technology is set up. Theoretical analysis says that optical multiplication frequency can improve the measurement resolution and reduce the nonlinearity through modifying the phase of nonlinearity and improve the cumulative error by the increment of the (v/c)2. The emulation results show that N times of optical multiplication frequency can effectively reduce nonlinear error by a factor of N and increase the cumulative error for N2 times. Optical multiplication frequency is used in low velocity situation.