A direct calculation of the normalized variance of irradiance for a beam wave of arbitrary aperture and focus in strong saturation employs a generalized function interpretation of the spherical-wave coherence function with the extended Huygens-Fresnel principle. The asymptotic limit is unity, and the limit of the probability distribution for the irradiance is exponential when the amplitude perturbation terms are neglected. Higherorder terms in the asymptotic series for a focused beam wave extend previously published results.
© 1976 Optical Society of America
M. H. Lee, R. A. Elliott, J. F. Holmes, and J. R. Kerr, "Variance of irradiance for saturated scintillations," J. Opt. Soc. Am. 66, 1389-1392 (1976)