Li Yuehua, Zhang Ziheng, Li Tiejun, Bian Wei, Niu Zhi, Liu Xiaohong, Zhou Jingbo
Opt Lett. 2025 Apr 1;50(7):2251-2254. doi: 10.1364/OL.553869.
We present a novel, to the best of our knowledge, design of a chromatic confocal displacement system (CCDS) based on spectral stripe. In this system, confocal light collected by the dispersive lens is shaped by a Powell lens and then diffracted onto a detector in the form of a thin straight stripe. The displacement variant is converted into the change of stripe positions on the detector. Unlike the spectral profile or the diffractive spot, the spectral stripe significantly increases the pixel number for analysis and effectively suppresses random noises. Simulation and experiment results show that the positional uncertainty of the spectral stripe is dramatically reduced and reaches less than 1‰ pixel. Measurement uncertainty is less than 14.3 nm within the whole measuring range of 4 mm. It provides a new way for developing large range CCDS with nanometer uncertainty.
据我们所知，我们提出了一种基于光谱条纹的新型彩色共焦位移系统（CCDS）设计。在该系统中，色散透镜收集的共焦光由鲍威尔透镜整形，然后以细直条纹的形式衍射到探测器上。位移变量被转换为探测器上条纹位置的变化。与光谱轮廓或衍射光斑不同，光谱条纹显著增加了用于分析的像素数量，并有效抑制了随机噪声。仿真和实验结果表明，光谱条纹的位置不确定性显著降低，达到小于1‰像素。在4毫米的整个测量范围内，测量不确定度小于14.3纳米。它为开发具有纳米不确定性的大范围CCDS提供了一种新方法。
