Abstract

Binary optics, which are capable of accurately generating arbitrary wavefront profiles in monochromatic light, can be very suitable for use as diffractive null correctors in the interferometric null test of an unusual aspheric surface. Unlike a computer-generated hologram, binary optics can be made with multiple levels causing them to resemble a blazed grating which concentrates energy into a single diffraction order such that order separation is not necessary. We will present a null test design which uses a binary optic as a null corrector for the test of an unusual non-symmetric aspheric surface. The selection of the test configuration, the design strategy, and the modeling/designing of the binary diffractive null corrector will be discussed. As a demonstration, we will show some interferograms from an experiment that uses a binary phase corrector to nullify the residual wavefront aberrations of a sphere tested at a conjugate other than its center of curvature.

© 1990 Optical Society of America