Title :
Investigation of optical losses in photoelastic and ridge waveguides in GaAs-AlGaAs heterostructures
Author :
Liu, Q.Z. ; Yu, L.S. ; Lau, S.S. ; Zappe, H.P. ; Epler, J.E.
Author_Institution :
Dept. of Electr. & Comput. Eng., California Univ., San Diego, La Jolla, CA, USA
fDate :
6/1/1996 12:00:00 AM
Abstract :
Two approaches have been used to fabricate stable photoelastic waveguides with planarized surfaces on GaAs-AlGaAs heterostructures. The first approach uses tensile Ni3GaAs stressors formed by metal-semiconductor reactions. The second approach uses inert, refractory and compressive stressors, such as RF sputtered W and RF co-sputtered WNi films. For comparison purposes, ridge waveguides have also been fabricated using the same heterostructure by a dry etching technique. Optical losses of photoelastic waveguides, measured by Fabry-Perot (FP) method at a wavelength of 1.53 μm, are comparable to or better than those of the ridge waveguides. Material loss appears to be the primary loss mechanism in both photoelastic and ridge waveguides. These results indicate that the photoelastic waveguide processing technique reported in this study is a promising alternative to commonly used dry etching techniques for planarization.
Keywords :
III-V semiconductors; aluminium compounds; etching; gallium arsenide; optical fabrication; optical losses; optical planar waveguides; optical testing; photoelasticity; ridge waveguides; semiconductor heterojunctions; sputter deposition; 1.53 mum; Fabry-Perot method; GaAs-AlGaAs; GaAs-AlGaAs heterostructures; Ni/sub 3/GaAs; RF co-sputtered WNi films; RF sputtered; W; WNi; compressive stressors; dry etching technique; loss mechanism; metal-semiconductor reactions; optical losses; photoelastic waveguide processing technique; photoelastic waveguides; planarized surfaces; refractory stressors; ridge waveguides; stable photoelastic waveguides; tensile Ni/sub 3/GaAs stressors; Dry etching; Optical films; Optical losses; Optical planar waveguides; Optical refraction; Optical waveguides; Photoelasticity; Planar waveguides; Radio frequency; Surface waves;
Journal_Title :
Photonics Technology Letters, IEEE