Experimental Study of Interference in Optical Fibers

Abstract

Feasibility of fiber optics for the measurement of the degree of coherence was confirmed experimentally. A diffraction pattern of the light from optical fibers was recorded on a photographic film and the pattern was analyzed in terms of spatial frequency by the diffraction method. The degree of coherence was evaluated from the diffraction powers associated with the interference between fibers. Despite the complex behavior of photographic emulsions, experimental results assure the feasibility of the method. The spatial and temporal coherence of a helium-neon laser are presented, which were obtained by this method.