PULSED EXCIMER-LASER DEPOSITION OF POTASSIUM TITANYL PHOSPHATE FILMS

Nonlinear optical thin films of potassium titanyl phosphate (KTP) have been successfully fabricated by pulsed excimer laser deposition on substrates of sapphire and Si. The films deposited on sapphire substrates in the temperature ranges of 450-550 degrees C show good crystallinity with preferential (100) and (011) orientations; on silicon, the films are polycrystalline. The stoichiometry of the films has been found to be Ti rich (about 20% higher). The effective refractive index of the films has been evaluated by spectroscopic ellipsometry with values between 1.75 and 2.0 in the spectral region 0.3-0.9 mu m, consistent with the bulk value. The deposited films show a promising nonlinear optical response with high second-harmonic generation efficiency, comparable to that of single-crystal KTP