Maréchal condition and the effect of aberrations on Strehl intensity.

The effect of aberrations on the Strehl intensity is analyzed. The aberrations are assumed to be random and normally distributed. A variety of different correlation coefficients for the aberration variation are discussed, including Gaussian correlation and Kolmogorov turbulence. For weak aberrations, the Strehl ratio is independent of the correlation function. The Strehl ratio for a given root-mean-square aberration is greater for a smaller number of correlation areas. For Kolmogorov turbulence, the Strehl ratio is lower than for Gaussian correlation.