Title :
Proton-exchanged optical waveguides in Z-cut LiNbO3 using phosphoric acid
Author :
Pun, Edwin Y B ; Loi, Kwok Kwong ; Chung, Po Shuen
Author_Institution :
Dept. of Electron. Eng., Chinese Univ. of Hong Kong, Shatin, Hong Kong
fDate :
2/1/1993 12:00:00 AM
Abstract :
Proton-exchanged Z-cut LiNbO3 planar waveguides formed using phosphoric acid were characterized optically. The refractive index profile and the diffusion parameters were studied systematically. These waveguides have propagation losses of less than 1 dB/cm and exhibit properties that are different from those obtained using benzoic acid. The index profile is not a simple step function and can be modeled accurately by a polynomial expression. A maximum surface index increase of 0.145 was measured at a 0.633-μm wavelength. The diffusion constant D0 and the activation energy Q for the proton-exchange process using this acid were found to be 6.43×108 μm2/h and 82.91 kJ/mol, respectively. The annealing properties of these waveguides were also established, and the effects of annealing on surface index change and waveguide depth increase were found to follow a power-law relationship
Keywords :
diffusion in solids; integrated optics; ion exchange; lithium compounds; optical waveguides; refractive index; 0.633 micron; LiNbO3; Z-cut; activation energy; annealing properties; diffusion constant; diffusion parameters; maximum surface index increase; optical constants; optical waveguides; phosphoric acid; planar waveguides; polynomial expression; power-law relationship; propagation losses; refractive index profile; waveguide depth; Annealing; Optical planar waveguides; Optical refraction; Optical surface waves; Optical variables control; Optical waveguides; Planar waveguides; Refractive index; Surface waves; Waveguide transitions;
Journal_Title :
Lightwave Technology, Journal of
