Photoinduced absorption in a planar BTO/BSO waveguide

We present the results of experimental observation of the dynamics of the absorption coefficient changing in the planar photorefractive waveguide Bi/sub 12/TiO/sub 20/ formed on Bi/sub 12/SiO/sub 20/ substrate. The Bi/sub 12/TiO/sub 20/ film with high optical quality was grown on a substrate of single-crystal Bi/sub 12/SiO/sub 20/ by crystallization from the melt. The radiation of helium-neon laser with the wavelength /spl lambda/=0.63 /spl mu/m was propagated through the waveguide, the light of red and green light-diode was used as background illumination. We investigate the photoinduced effect for low-number (1-3) and high-number (7-10) waveguides modes with background illumination and without one.