2D－SROP－1型光学轮廓仪中调制误差的分析与抑制

Analysis and Decreasing of the Micro-displacement Modulation Error in Optical Profilometer

应用ＰＺＴ作为微位移驱动机构，研制成２Ｄ－ＳＲＯＰ－１型光学轮廓测量仪，它的垂直分辨率可达１ｎｍ，可测量Ｒｎ＜０．１ｕｍ的表面。本文分析了微位移调制误差对仪器的影响，导出了测量相位偏差４ψ与调制误差△β的关系，考查了串联电容对微位移特性的影响。结果表明，在微位移调制器上串联一适当电容，使在仪器工作频率范围内响应线性度达到１．０８％，保证了仪器的测量精度。

By using PZT as micro-displacement actuator,the vertical resolution of an optical profilometer developed can reach to 1nm. The instrument can perform precision measurement of surface with roughness Ra less than 0.1um.This paper analyzes the influence of the micro-displacement modulation error on the measuring accuracy of the instrument,and gives the method of improving the linearity of displacement-capacitance dynamic response of the micro-displacement modulator to guarantee the accuracy of the instrument.