Design of a freeform curved prism imaging spectrometer based on an anastigmatism
- Received Date: 2019-03-12
- Rev Recd Date: 2019-04-03
- Available Online: 2020-06-29
- Publish Date: 2020-08-01
Abstract: In this paper, an algorithm for calculating the initial structure of the Offner freeform curved prism imaging spectrometer with secondary mirror external reflection is designed. The ray tracing method is used to obtain the formula for the propagation of light on the optical surfaces of an Offner spectrometer with secondary mirror external reflection. The formula can determine the structural parameters of the optical component. The off-axis beam astigmatism theory commonly used in the analysis of off-axis systems is used to analyze image quality, and a reasonable threshold is set to judge the structure algorithm. The initial structure that meets the design requirements is obtained through iterative optimization in Matlab and the initial structure is optimized in Zemax. To verify the performance of the proposed algorithm, the initial structure of a free-form prism spectrometer with a spectral range of 380~780 nm, a numerical aperture of 0.15 and a spectral resolution of 6 nm is designed. After being optimized in Zemax, the system reached the design index and the spectral line bending and color distortion are both less than 0.1 pixels. The algorithm proposed in this paper can quickly calculate the initial structure such that the requirements are satisfied, and can simplify its complexity.
|Citation:||ZHANG Jia-lun, ZHENG Yu-quan, LIN Chao, JI Zhen-hua. Design of a freeform curved prism imaging spectrometer based on an anastigmatism[J]. Chinese Optics, 2020, 13(4): 842-851. doi: 10.37188/CO.2019-0049|