基于波动光学模型的光谱共焦色散物镜像差分析及校正

Analysis and Correction of Aberrations in Spectral Confocal Dispersive Objectives Based on Wave Optics Model

摘要:

基于波动光学模型分析了像差存在时光谱共焦系统的光谱响应，并提出了像差校正方法。首先，介绍了系统的工作原理和色散物镜的色散模型，并建立了基于波动光学模型的光谱响应模型，研究并分析了像差对轴向光谱响应的影响；仿真结果表明，球差、彗差及像散会引起峰值高度降低；球差和像散会引起峰值波长发生偏移；而像散会使信号产生次峰现象，且导致边缘信号产生畸变。其次，基于计算像差理论，提出了对像差影响的峰值误差校正方法。最后，利用光谱响应信号的半高全宽验证了像差校正方法的有效性。结果表明，校正后的光谱响应峰值位置更加准确，信号更集中，分辨率提高。本文的研究内容对提高光谱共焦系统的测量精度和分辨率有一定的指导意义。

Abstract:

Based on the wave optics model, the spectral response of the spectral confocal system in the presence of aberrations is analyzed and an aberration correction method is proposed. The working principle of the system and the dispersion model of the dispersive objective are introduced, and a spectral response model based on the wave optics model is established, with the influence of aberrations on the axial spectral response being studied and analyzed. It is shown by the simulation results that the decrease in peak height is caused by spherical aberration, coma and astigmatism, the shift in peak wavelength is led by spherical aberration and astigmatism, and the secondary peak phenomenon of the signal as well as the distortion of the edge signal is resulted from astigmatism. Then, based on the computational aberration theory, a peak error correction method for the influence of aberrations is proposed. Finally, the effectiveness of the aberration correction method is verified by utilizing the full width at half maximum of the spectral response signal. It is indicated by the results that after correction, the peak position of the spectral response is made more accurate, the signal is made more concentrated and the resolution is improved. The research content of this paper is of certain guiding significance for the improvement of the measurement accuracy and resolution of the spectral confocal system.