title: Third-order coma-free point in two-mirror telescopes by a vector approach.
abstract: In this paper, two-mirror telescopes having the secondary mirror decentered and/or tilted are considered. Equations for third-order coma are derived by a vector approach. Coma-free condition to remove misalignment-induced coma was obtained. The coma-free point in two-mirror telescopes is found as a conclusion of our coma-free condition, which is in better agreement with the result solved by Wilson using Schiefspiegler theory.
authors.affiliation: Changchun Institute of Optics, Fine Mechanics and Physics, Chinese Academy of Sciences, Changchun, Jilin 130033, China. renbc@yahoo.cn
authors.forename: Baichuan
authors.initials: B
authors.lastname: Ren
authors.forename: Guang
authors.initials: G
authors.lastname: Jin
authors.forename: Xing
authors.initials: X
authors.lastname: Zhong