FIELD: optics. SUBSTANCE: device includes first structure that carries out phase shifts for individual photons of laser beam having coherence L in correspondence with preset distribution. Root-mean-square value of difference obtained as result of phase shift in length of path is longer than length of coherence L multiplied by coefficient 1/(12)1/(12)1/2. First structure can be fabricated from clear material with some particles having higher refractive index included into it. Device can incorporate second structure that includes elements enabling length of coherence of laser beam to be shortened. EFFECT: reduction of speckles. 19 cl, 10 dwg
