Design of Dispersive Objective Lens of Spectral Confocal Displacement Sensor

According to the working principle of the spectral confocal displacement sensor, four kinds of glass materials SKIO, H-ZLAF52A, N-LAK34 and SFL6 for dispersive lens are selected. 4 single lenses and one doublet lens are components of the initial structure of the linear dispersion objective lens. Optical design software is used to optimize the tolerance of the initial structure of the dispersive objective lens. The results show that the spot diagram of each wavelength is much smaller than the Airy disk. in the wavelength range of 450-700nm, the measurement range of the dispersive objective lens can reach 3.454 mm, and the linear determination coefficient R2 between the axial dispersion diatance and the wavelength is 0.972.