线性色散设计的光谱共焦测量技术

研制了高精度的光谱共焦位移测量系统并完成相关测试。基于色差理论和材料优化选择设计一种色差与波长成线性关系的色散物镜,有助于平衡系统在全测量范围的灵敏度。理论分析了系统参数对系统的影响规律,计算了针孔尺寸与系统的分辨率和信噪比的关系,给出了参数优化结果。利用设计的线性色散物镜和参数优化结果,构建了光谱共焦测量系统,完成了系统的校准、测试和应用研究。结果表明,系统的轴向测量范围达到1 mm,分辨力优于0.5μm,全程测量误差小于2μm,符合设计要求。

Chromatic confocal microscope with linear dispersive objective

We built a chromatic confocal microscope for micro metrology. Based on dispersive aberration principle and optimization of lens glasses, a dispersive objective was designed, of which the dispersive aberration was linear to wavelength. The linear dispersive aberration could help to balance the sensitivity of chromatic confocal microscope. Designed dispersive objective is of large dispersive aberration, small longitudinal aberration and long working distance. Influence of system parameters on optical sectioning was analyzed and simulation results were exhibited. Chromatic confocal microscope was built, calibrated and tested. Experimental results show that the measuring range is 1 mm, the resolution is better than 0.5 m and the measuring error in full range is less than 2 m. To test the performance of microscope, profile of standard height was scanned and thickness of transparent plate was measured.