Observation of phase boundaries in spontaneous optical pattern formation

Abstract

With measured optical images in spontaneous pattern formations, we observe the phase boundaries in the phase diagram, defining by the degree of coherence and biased voltage. Pattern transitions in the form of stripes, reoriented stripes, hexagons, and spots are revealed experimentally and theoretically for incoherent beams in noninstantaneous anisotropic photorefractive crystals, with demonstrations in the boundary of mixed-phase states.