RAMAN INVESTIGATION OF THE NONLINEAR-OPTICAL PHENOMENON OF POLARIZATION ROTATION IN TILINBO3 CHANNEL WAVE-GUIDES

The nonlinear phenomenon of polarization rotation in Ti:LiNbO3 optical channel waveguides was investigated using Raman microprobe microscopy . Polarization sensitive Raman selection rules permitted the identific ation of polarization rotation of the propagating transverse electric or transverse magnetic waveguide mode. From an analysis of the Raman s cattered light collected orthogonal to the waveguide surface the thres hold power necessary to initiate the process of mode conversion could be determined. In addition, the Raman microprobe was used to determine waveguide loss coefficients by collecting inelastically scattered lig ht. The values obtained by this method were compared to those measured by collecting the elastically scattered light. A value for the asymme tric component, beta15, of the photovoltaic tensor was calculated to b e 7.8 x 10(-13) A/W for the X-cut, Y-propagating and 3.8 x 10(-14) A/W and 1.2 x 10(-14) A/W for the rapid thermally annealed Z-cut, Y-propa gating channel waveguides, respectively.