Optics and Photonics Society of Iran

In this article a baffle is designed for Cassegrain telescopes based on combination of the results of ray tracing in zemax optical design software and iterative method. The method finds the exact solution for baffle parameters of a Cassegrian telescope by iteratively solving the analytical relations using the actual ray coordinates of the cassegrain telescope computed with the aid of optical design software. For example, the baffle parameters in the Iranian National Observatory (INO340) telescope are calculated. In Cassegrain telescopes image plane is located behind the primary mirror so stray light directly reaches the image plane. This stray light reduces image quality of the telescope system. In these systems by designing baffles near the primary and secondary mirrors, direct stray light could be eliminated. In the Cassegrain telescopes secondary mirror causes the central obscuration and the baffle creates additional obscuration for the imaging light. In this method, the minimum obscuration is provided.