Diffractive analysis of limits of an occulter experiment

Abstract

An external occulter is a specially-shaped spacecraft own along the line-of-sight of a space telescope to block starlight before reaching its entrance pupil. Using optimization methods, occulter shapes can be designed to most effectively block starlight. A full-scale occulter cannot be tested on the ground and its performance must be predicted; therefore the fidelity of the optical propagation models used for design and performance prediction must be verified under scaled conditions. In this paper we present both contrast and suppression laboratory measurements for a scaled occulter, and perform a diffractive analysis to determine the factors limiting performance of the laboratory occulter.