Abstract

An adaptive optics system that utilizes a segmented mirror as the active component is described and discussed. The mirror is a 10-in. diam spherical mirror composed of 13 independently controllable segments of equal area. The system linearity and control laws are discussed assuming a modal wavefront expansion. Two approaches to modal aberration expansion are briefly outlined using (1) Zernike polynomials as the basis set and (2) a modified set of Zernike polynomials. Both approaches allow calculation of the coefficient vector with a matrix–vector multiplication if a fixed sampling geometry is used. Assuming the employment of Zernike polynomials in the wavefront expansion, the feedback matrix G which governs actuator movement in the presence of measured aberration is computed. The mirror fitting errors to the Zernike polynomials are then estimated, and a finite number of polynomials are chosen which can be adequately corrected.

© 1987 Optical Society of America