SBN thin film growth by pulsed laser deposition and study of nonlinear optical properties

Strontium barium niobate (SrxBa1-xNb2O6) thin films were grown by PLD and c haracterized as to their structure, composition, and both linear and nonlin ear optical properties. Attempted composition of very nearly x=0.61 was ach ieved, as shown within experimental error of RES and PIXE techniques. Films deposited with high growth rates and at 700 degrees C substrate temperatur e resulted polycrystalline on (001)-cut MgO and amorphous on fused silica, while those grown on MgO at lower growth rates were very well oriented with the substrate. A considerable blue shift in the absorption band edge was o bserved for the disordered SBN:61 films, compared to that for bulk SBN:61 c rystal. A broad luminescence band was observed to occur, similar to that fo r bulk SBN. Degenerate four-wave-mixing techniques were used to study the n onlinear optical response of the amorphous films. A considerable enhancemen t, by 2 orders of magnitude, of the third order nonlinear susceptibility ch i((3)) in transverse alignment was found to occur with respect to bulk valu es. A significant squeezing of the coherent response signal was observed in the SBN films.