Fast photorefractive response in B12SiO20 in the near infrared

The polarization self-modulation effect was applied for effective measurement of the characteristic response time of nominally pure Bi12SiO20 (BSO) at wavelengths of 810 and 980 nm. Owing to oxygen deficiency in the crystal lattice, the BSO crystals showed unusual photorefractive sensitivity and remarkable operation speed in the near-infrared spectral region. A response time of 130 ms was measured at 810 nm, and a response time of 540 ms was measured at 980 nm, with incident intensities of 110 and 200 mW/cm(2), respectively. To our knowledge, this is the first experimental evidence of a subsecond response in the infrared for a nonsemi-conductor photorefractive material. (C) 2000 Optical Society of America OCIS codes: 160.5320, 190.4400, 190.5330.