<title>Defining mirror quality: a global approach</title>

Abstract

We investigate the problem of defining the quality of a mirror from a global point of view, wherein both the low and high frequency errors are taken into account. We compute their effects on the MTF, EE and the PSF. It is found that there is a critical value of the rms wavefront error due to high frequency errors (about 30 nm), beyond which the EE profiles flatten out considerably. We conclude that the quality of a mirror has to be defined taking account the rms wavefront errors of the high frequency errors as well.