Abstract: An optical device and method for testing high reflectivity autostigmatic optical elements and systems is disclosed. A thin, partially transmissive optical element, e.g., a pellicle with an optical coating having a transmission factor determined by the nominal reflectivity of the test article, is placed in the measurement leg of a spherical wavefront Fizeau interferometer so that high contrast, two-beam interference fringes can be obtained from a high reflectivity autostigmatic optical element or system.

Abstract: An apparatus is disclosed which automatically measures the geometrical deviations of a reflecting surface from a reference surface, and which also can be used to automatically measure the deviations of some light beam deviating property of a transparent article from a reference in a non-contacting manner over a plurality of lines on the article being measured. A narrow beam of laser light is scanned simultaneously in a raster pattern over the test article and a reference surface. A uniformly rotating multi-faceted reflector device which has suitably chosen pyramidal angles and which is placed near the focal point of a collimating lens produces the scaning, collimated laser beam.

Abstract: An opto-mechanical apparatus is described which produces a scanning laser beam moving with a constant linear velocity, where velocity is used in the vector sense. The scanned beam can be either collimated or focused. By reflecting a laser beam from a uniformly rotating mirror to produce a rotationally scanned beam of uniform angular velocity, locating said mirror at the focus of a specially designed lens which follows the formula h=k.sup.. .theta., where h is the distance between the center of the linearly scanned beam emerging from the lens and the optical axis, .theta. is the angle between the center of the rotationally scanned beam and the optical axis, and k is a constant very nearly equal to the back focal length of the lens, a scanning laser beam is produced which moves with a uniform linear velocity.