针对彩色共焦距测量系统中测量范围和分辨率的调制问题, 采用色散和聚焦功能分离的思路设计了一款色散物镜, 其色散功能由纯球面折射透镜组成的色散管镜来实现, 聚焦功能则采用商业物镜实现。使用ZEMAX软件对色散管镜的结构、材料及像差进行了设计及优化, 仿真结果显示所设计的色散管镜在可见光范围内能获得优于230 mm的轴向线性色散, 实际加工的成品管镜的轴向线性色散范围可达160 mm。实验测量了色散管镜及它结合不同聚焦物镜后的色散特性。实验结果表明, 色散管镜结合不同聚焦能力的物镜能够具有高线性度的轴向色散区域; 结合4倍和10倍放大倍率的商用物镜, 分别获得了1 300 μm和225 μm的测量范围, 其轴向分辨率分别为2 μm和0.4 μm, 实现了测量范围和分辨率的调制。

Aiming at the adjustment of measuring range and resolution in Chromatic Confocal Microscopy (CCM), a dispersive objective for chromatic confocal system was designed, which can realize chromatic dispersion and focusing function separately. The chromatic dispersion was achieved through a dispersion tube lens, which was composed of pure spherical refraction lens. The focusing function was accomplished by a commercial objective lens. The structure, material and aberrations of the dispersive tube lens were designed and optimized by ZEMAX software. The simulation shows that the axial linear chromatic dispersion is better than 230 mm in visible waveband. Moreover the axial linear dispersion range of the finished tube lens can be up to 160 mm. The dispersion characteristics of the tube lens combined with different focusing objective lenses were determined experimentally. The results show that the axial dispersion region with high linearity can be maintained in the case of different focusing objective lens. With commercial objective lens of 4x and 10x magnification, the measurement ranges of 1 300 μm and 225 μm are obtained with axial resolution of 2 μm and 0.4 μm respectively. Thus, the modulation of measurement range and resolution is achieved.