Aberration analysis of reflective and transmissive type optical spectrometer using Zemax

This study presents a detailed analysis of geometrical aberrations in reflective and transmissive optical spectrometers using Zemax optical design software. Wavefront aberration, a standard metric for assessing geometrical aberration in optical systems, is employed to evaluate performance. Spectrometers are designed in sequential mode and analyzed with the physical optics propagation (POP) algorithm. Key performance metrics, such as optical path difference (OPD), transverse ray plot, spot diagram, modulation transfer function (MTF), and geometric encircled energy, are used to assess the spectrometers. This analysis aims to study aberration effects that cause distorted and blurry spectra, ultimately impacting spectrometer accuracy and efficiency. A comparative analysis of both spectrometers in the visible range for zero and first-order diffraction grating is reported. Line and edge spread functions are simulated to examine the spectrometer’s resolution capability. This study comprehensively compares optical spectrometers, highlighting their applicability across various fields.