Abstract

Traditionally, the Fraunhofer diffraction formulation has been considered to be an adequate approximation for the calculation of light distribution in the diffraction plane for most purposes. It has proved effective in the system design and those scientific applications where the intensities of two sources differ by up to a few orders of magnitude. Due to continued interest in detecting dim objects in the neighborhood of bright objects, a more nearly exact formulation of diffraction theory is needed to calculate the distribution of the diffracted light in the focal plane when the intensity ratio between the dim object and the bright object approaches 10 exp(−8). This is the case when an extrasolar planet is searched for in the presence of its star. The vector diffraction theory, geometrical diffraction theory, and Fraunhofer diffraction formulations are compared for their applicability to solving simultaneously two diffraction problems with intensity ratios of incident illumination varying from 10 exp(−3) to 10 exp(−8).

© 1989 Optical Society of America