High resolution alignment interferometer

摘要

In an interferometer a beam-splitter reflector such as a compound prism is provided having an interface and a base normal thereto. An entrance face and exit face are aligned with respect to the interface to provide a zero order interface fringe along an axis of one face when a reflecting surface such as an autocollimating mirror is parallel to the base. Also, the zero order interference fringe is fixed at the apex of the prism and rotates as a function of angular misalignment of the reflecting surface with respect to a plane parallel to the prism base. Position of the fringe is measured to provide a high resolution indicaton of angular misalignment of the reflecting surface.