SPECTROSCOPIC AND PHOTOREFRACTIVE PROPERTIES OF INFRARED-SENSITIVE RHODIUM-DOPED BARIUM-TITANATE

We have grown and characterized crystals of BaTiO3 doped with Rh. Thes e crystals have a blue-green color that is probably due to charge-tran sfer optical transitions involving Rh4+ and/or Rh3+. Electron paramagn etic resonance spectroscopy confirmed the presence of Rh4+ centers. Se lf-pumped phase-conjugation measurements were performed at wavelengths between 776 and 990 nm. Reflectivities near 80% were obtained through out this wavelength range. In addition, self-pumped phase-conjugation buildup times were measured as a function of input power at 851 nm and are significantly faster than in undoped or Co-doped crystals studied previously. BaTiO3:Rh is therefore a promising material for near-infr ared photorefractive applications.