Optically controlled holographic beam splitter

We present the results of realization and study of a light beam splitting effect based on a full-optically controlled holographic diffraction grating. The high quality, light responsive, periodic structure, which is exploited as tunable beam splitter, is monitored by combining its zero and first diffracted orders in a Mach–Zehnder geometry interferometer. The interference pattern exhibits a dependence of the fringe visibility on the external optical pump power utilized to drive the splitting effect. The visibility, characterized by means of a standard pump-probe optical setup, reveals a strong dependence on the polarization of the probe radiation and on its incident angle as well. The effect is reversible and repeatable, and shows a continuously adjustable fringe visibility in the range 0.94–0.2, with response times in the millisecond range.