Jun UOZUMI, Katsuhiro UNO and Toshimitsu ASAKURA

Research Institute for Electronic Science, Hokkaido University, Sapporo, 060 Japan

(Received January 17, 1995; Accepted March 20, 1995)

Some first-order statistics of speckle fields obeying the complex Gaussian probability density are investigated with the special emphasis on a possibility for the speckle contrast to exceed unity. It is shown that such enhanced fluctuations of speckle fields are generated when the probability density of the complex amplitude is non-circular with the vanishing mean. This means that Gaussian speckles having the contrast of unity are not necessarily fully developed speckles. Some practical situations producing such enhanced fluctuations in speckle fields are discussed.

Key words : Gaussian speckle, contrast enhancement, non-circular statistics, circularity, gamma density