Optimization of deep-etched, single-mode GaAs-AlGaAs optical waveguides using controlled leakage into the substrate

Author

Heaton, John M. ; Bourke, Michelle M. ; Jones, Sylvia B. ; Smith, Brian H. ; Hilton, Keith P. ; Smith, Gilbert W. ; Birbeck, Jeremy C H ; Berry, Graham ; Dewar, Susan V. ; Wight, David R.

Author_Institution

Defence Evaluation & Res. Agency, Malvern, UK

Volume

17

Issue

2

fYear

1999

fDate

2/1/1999 12:00:00 AM

Firstpage

267

Lastpage

281

Abstract

This paper presents a detailed experimental and theoretical study of the properties of deep-etched GaAs-AlGaAs optical waveguides designed using a version of the spectral index method which predicts mode losses due to leakage through the lower cladding into the high index GaAs substrate. By predicting and measuring the mode losses due to this mechanism as a function of guide width, we show that waveguides formed by reactive ion etching through the core to the lower cladding layer can be both low-loss (0.2 dB/cm) and single-mode even with core thicknesses and guide widths as large as 4.8 and 5.6 μm, respectively. We demonstrate the advantages of this type of guide for making compact integrated optic devices

Keywords

III-V semiconductors; aluminium compounds; claddings; etching; gallium arsenide; integrated optics; optical design techniques; optical losses; optical waveguide theory; optical waveguides; optimisation; refractive index; substrates; 4.8 mum; 5.6 mum; GaAs-AlGaAs; compact integrated optic devices; controlled leakage; core thicknesses; deep-etched GaAs-AlGaAs optical waveguide design; deep-etched single-mode GaAs-AlGaAs optical waveguide optimisation; guide width; high index GaAs substrate; lower cladding; mode loss measurement; mode losses; reactive ion etching; spectral index method; substrate; Etching; Gallium arsenide; Light scattering; Optical control; Optical crosstalk; Optical scattering; Optical waveguide theory; Optical waveguides; Semiconductor waveguides; Substrates;

fLanguage

English

Journal_Title

Lightwave Technology, Journal of

Publisher

ieee

ISSN

0733-8724

Type

jour

DOI

10.1109/50.744237

Filename

744237