PHOTOREFRACTIVE PLANAR WAVE-GUIDES IN BATIO3 FABRICATED BY ION-BEAM IMPLANTATION

For the first time to our knowledge, photorefractive properties have been observed in planar waveguides fabricated by the technique of ion-beam implantation in BaTiO3 single crystals. The implantation was carried out by using 1.5-MeV H+ ions at a dose of 10(-16) ions/cm2. For a given input power, a decrease in the effective photorefractive two-beam coupling response time of greater-than-or-equal-to 10(2) has been observed, owing to a combination of optical confinement within the waveguide and possible modification of charge-transport properties induced through implantation. Experiments carried out on the two-beam coupling gain show that the gain direction has been reversed in the waveguide compared with that of the bulk crystal.