Abstract

An initial attempt was made applying spatial filtering to the point image of the return wavefront. This image showed a pronounced bowtie diffraction pattern generated by the concentric circular arcs of the pupil function. By experimenting with circular pinholes of various sizes we were able to smooth the wavefront dramatically. Wavefront slope errors were reduced from 0.015 waves/mm to 0.005 waves/mm. Results of this experiment will be presented and other questions raised by this attempt will be discussed.

© 1990 Optical Society of America