Abstract

Lenses designed and manufactured for use in optical projectors are often touted as diffraction-limited. However, small amounts of higher-order aberrations, which may appear negligible when standard lens-quality criteria are applied, can in practice significantly reduce image quality when the lens is used in an optical projector. We demonstrate, via computer simulation, how two wavefronts with so-called diffraction-limited modulation transfer functions and the same high Strehl ratio of 0.97 can have different imaging properties. We explore how the line ratio (the ratio of the sub-resolution-line image maximum normalized to the aberration-free case, in analogy to the Strehl ratio) can be used as a criterion for evaluating imaging performance in optical projectors.

© 1991 Optical Society of America