Formation, decay, and erasure of photorefractive gratings written in barium titanate by picosecond pulses

• DOI: 10.1364/josab.6.000606
• Publication Date: 2008-12-01T15:29:33Z
• Authors: Arthur L. Smirl; George C. Valley; Ruth Ann Mullen; K. Bohnert; Thomas F. Boggess
• Keywords: 0103 physical sciences; 01 natural sciences; 7. Clean energy

Photorefractive gratings are written, read out, and erased with single 30-psec pulses at fluences of 1–15 mJ/cm2 and a wavelength of 0.532 μm in a BaTiO3 crystal. The gratings consist of one component that is fully formed 50 psec after the peak in the writing beams and a second component that grows for approximately 30 sec until it starts to decay by dark erasure. The photorefractive index change per absorbed photon for picosecond pulses is approximately the same as that obtained when a cw beam at 0.515 μm is used with the same crystal. The index change is approximately a factor of 30 smaller than that observed at the same fluence in GaAs at 1.06 μm when the same picosecond laser system is used.