Abstract

A design for a new diffractive focusing optic is presented. This device is a blazed phase optic having an order-of-magnitude fewer zones than a conventional kinoform of similar functional parameters, yet the theoretical Strehl ratio is shown to be very high (>98%). The reduction in the number of zones is achieved by varying the heights of the steps; this results in larger zones and an optic that is more easily manufactured. Several large aperture (50 mm), f/2 Superzone optics were fabricated using micromachining methods. These were measured with a commercial interferometer and point spread functions were determined.

© 1991 Optical Society of America