Oscillating photocurrents are generated in a photorefractive iron-doped barium calcium titanate crystal (Ba<sub>0.77</sub>Ca<sub>0.23</sub>TiO<sub>3</sub>; BCT) by illumination with an oscillating interference pattern. Non-steady-state photocurrents arise usually from the interaction of a space-charge field with an oscillating photoconductivity pattern. However, a second-harmonic signal of the oscillating photocurrents is observed in BCT, which is present without any space-charge field. The main features of the new effect can be explained by consideration of a dynamic, i.e., time-dependent, bulk photovoltaic effect. The effect might be useful for optically addressed memories or optical correlators.
© 1999 Optical Society of America
(050.7330) Diffraction and gratings : Volume gratings
(100.4550) Image processing : Correlators
(160.2900) Materials : Optical storage materials
(160.5320) Materials : Photorefractive materials
(190.5330) Nonlinear optics : Photorefractive optics
N. Korneev, D. Mayorga, H. Veenhuis, K. Buse, and E. Krätzig, "Dynamic bulk photovoltaic effect in photorefractive barium calcium titanate," J. Opt. Soc. Am. B 16, 1725-1729 (1999)