TY - JOUR T1 - Design of perfect null compensator, using a single lens, with capability to converting flat wavefront to parabolic wavefront for testing parabolic surfaces with interferometry methodر TT - طراحی جبران‌کننده‌ی کامل تک عدسی با قابلیت تبدیل جبهه‌ی‌موج تخت به سهموی، به منظور اندازه‌گیری دقت سطوح سهموی به روش تداخل‌سنجی JF - opsi JO - opsi VL - 23 IS - 0 UR - http://opsi.ir/article-1-1172-en.html Y1 - 2017 SP - 977 EP - 980 KW - perfect null compensator KW - Aspheric KW - Parabolic KW - Interferometry KW - Optical Design N2 - In this article, by design of a single lens, perfect optical null compensator, flat output wavefront of an interferometer is converted to parabolic wavefront and by that, parabolic surfaces can be tested. In method that is presented in this article, design of null compensator is done by using of one single lens that one side of that is aspherical. By using this single element null compensator, in comparing by two elements null compensators, it is not necessary to do accurate adjustment of distance between these two lenses and also it is not necessary to do accurate adjustment of alignment of them and according to these, accuracy of measurements is increased significantly. In addition, by reduction of number of lenses, surface error of lenses and also error of homogeneity of optical materials is reduced significantly. M3 ER -