Raman Spectra of Proton-Exchanged LiNbO₃ Optical Waveguides

Based on the Raman spectrum measurement, we investigate the mechanism of proton exchange, by which the optical waveguides are formed in the LiNbO₃ crystal which are proton doped. The proton source is formed by a mixture of benzoic and adipic acids. The experimental results show that there is a Raman formant peak of optical waveguide at 650 cm^-1, and the higher the relative percentage of the mol ratio of adipic acid dilution, the higher the intensity of the Raman formant peak.