a method of reducing the appearance of speckle resulting from a coherent light beam , includes the steps of : providing an electro - optic device having , an electro - optic substrate , an electrode array arranged on the surface of the electro - optic substrate , at least one electrode located on the opposite surface of the electro - optic substrate , and means for applying voltage to the electrodes to generate a variation in a refractive index profile within the substrate ; and directing the light beam through the electro - optic device while applying voltage to the device , whereby the temporal and spatial phase of a light beam passing through the substrate is altered , thereby reducing the appearance of speckle .