Rewritable filter in a photorefractive BCT crystal

Waveguiding structures in photorefractive materials attract attention due to possible applications in optical information processing like splitting, switching or filtering of light beams. In this work we present a rewritable filter (REFIL) based on a waveguide (1D spatial soliton) and a grating in this structure. The experiments were carried out with a BCT crystal, whereas different writing methods of the grating in the soliton were applied. First, the grating and afterwards the waveguide were written. In a second case the waveguide and afterwards the grating were generated, and, third, the waveguide and the grating were written simultaneously by counter propagating solitons. The maximal diffraction efficiency of the grating was about 3%.