The photorefractive reflection gratings recording in bismuth titanium oxide crystals

Photorefractive crystals are an interesting matter class due to the possible application of their photorefractive properties in optical data processing and phase conjugation of light beams as well as in holographic interferometry and optical sensors. We studied an undoped Bi/sub 12/TiO/sub 20/ (BTO) crystal grown from high-temperature melt. A typical feature of BTO crystals is a considerable light-induced absorption at /spl lambda/ = 633 nm that may lead to noticeable changes in the dynamics of two-beam coupling as well as in its steady-state value. We investigated the dynamics of two-beam coupling on a reflection grating and of light-induced absorption. The [100] cut BTO sample with optically polished [100] faces had thickness d = 3.46 mm and specific optical rotation p = -6.5/spl deg/ mm/sup -1/.