The effect of proton exchange carried out using benzoic and pyrophosphoric acid on the nonlinear optical coefficient (d) of LiNbO3 and LiTaO3 was studied using a second-harmonic generation reflectance technique. Significant degradation in the d coefficient of LiNbO3 and LiTaO3 was observed as a result of proton exchange with either benzoic or pyrophosphoric acid under the conditions studied. Some recovery only in the short time proton-exchanged sample (0.5 h at 180°C) of LiNbO 3 was observed under thermal annealing at 350°C for 1 h. Results of in situ measurement of second-harmonic signal recovery under thermal annealing are reported. Results are also presented on theoretical and experimental variations of second-harmonic generation intensity with an incident polarization angle.
All Science Journal Classification (ASJC) codes
- Physics and Astronomy (miscellaneous)