Analysis of image quality requirements for multispectral mirror systems

Abstract

The paper presents an analysis of changes in image quality that occur in optical system with a spectral range shift. A basic system was designed for the visible range with the prospect of receiving objectives operating in the range from UV to IR. In the process of transition from the wavelength of 0,55 μm to 0,2 μm, a dramatic drop for initially diffraction quality system in the Strehl number by 1,5 times was found. However, since this criterion does not represent the features of the image quality drop, both Strehl and other computed image quality parameters (Rayleigh and Marechal criteria) cannot be recommended as universal requirements for systems with an unspecified spectral range. An assessing the multispectral system image quality by MTF is proposed. Based on this, conclusions about the initial requirements for image quality of multispectral systems can be acquired. The conclusions are made based on the experience of designing a Schwarzschild mirror objective with a numerical aperture of 0.8 for the range of 0,21-2 µm. © 2023 Elsevier B.V., All rights reserved.