Chen Bao-Xue

As2S8 planar waveguide: refractive index changes following an annealing and irradiation and annealing cycle, and light propagation features

The refractive index of as-evaporated amorphous semiconductor As2S8 film upon an annealing and saturation irradiation and annealing cycle is reversible. Upon successive treatment with annealing and non-saturation irradiation and further annealing, the refractive index of the as-evaporated amorphous semiconductor As2S8 film reaches a maximum value and then its reversibility occurs upon annealing. The annealing of the amorphous semiconductor As2S8 films results in the stabilization of the structure through changes of the S-S bonds in the nearest environment, accompanied by a decrease of film thickness. The As2S8 planar waveguide after annealing (130 °C) and saturation irradiation and annealing (130 °C) shows a good propagation characteristic with ca. 0.27 dB/cm low propagation loss of the 632.8 nm guided mode.

Raman Spectra of Proton-Exchanged LiNbO3Optical 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.