Digital holographic fractal speckle

It has been shown in previous studies that fractal speckles can be produced in an image plane by using as a pupil filter in the imaging system a spatial light modulator with an intensity transmittance obeying a negative power-law. However, this method has a disadvantage in that the intensity distributions of such speckles are very low due to the pupil filter giving a lower total transmittance. To overcome this disadvantage, we propose here the use of digital holography to generate fractal speckles. The theoretical background is explained briefly, and experimental results are shown.