FIBER-COUPLED OPTICAL CHANNEL WAVEGUIDE ARRAY ALLOWING FOR TEMPERATURE INDEPENDENT OPERATION AND SIGNAL TRANSFORMATION

The analytical derivation of the dispersion characteristics of arbitrarily-shaped inhomogeneous waveguides by using the finite element technique has been carried out. The techniques of prism-film coupling and ellipsometry in characterizing the film thickness and refractive index of optical waveguides have been introduced. Fabrication techniques including wet chemical etching, dry plasma etching and lift-off techniques have been introduced. A novel lift-off technique used in the fabrication of the glass channel waveguide has been successfully demonstrated.;The concept of having the effective refractive index of an optical waveguide mode be independent of temperature is introduced. It is shown that this concept should be realizable with a Corning 7059 glass thin-film waveguide supported on a SiO(,2)-Si substrate for a waveguide thickness of 0.37 (mu)m. Measurements of effective refractive index as a function of temperature confirm this prediction of temperature independence in that they show a very small variation with temperature for a 0.35 (mu)m thick waveguide in comparison with that for a 0.98 (mu)m thick waveguide.;A thin-film beam splitter fabricated by using glass channel waveguides has been introduced. The experimentally-measured splitting ratios of the light beam agree well with the SEM-measured beam splitter extent to channel waveguide width ratios. Due to the absence of total reflection of the V-shaped reflector, the sum of the output light intensity and the deflected light intensity is 0.34 dB less than the input light intensity.;Curved channel waveguide with zero slopes at the two ends have been first designed by using cubic Hermitian interpolation. A 32 element fiber-coupled tapered channel waveguide array has been designed and successfully operated using the preferential etching technique. A 13.3% coupling efficiency and average loss of 7 dB having deviation of less than 3.5 dB was measured. A novel tapered fiber to channel waveguide coupling structure was the designed and fabricated. An improved coupling efficiency of 59.5% was obtained. Four 90(DEGREES) curved channel waveguides with radii of 2.5, 5.0, 7.5 and 10 mm and CO(,2) laser-tapered optical fibers have been used to examine the curvature and tapering losses experimentally. The experimental results of the curvature and tapering losses have been shown to agree well with theoretical predictions.