Refractive-index profiling of graded-index planar waveguides from effective indexes measured for both mode types and at different wavelengths

Author

Chiang, Kin Seng ; Wong, Chi Lai ; Chan, Hau Ping ; Yuk Tak Chow

Author_Institution

Dept. of Electron. Eng., City Univ. of Hong Kong, Hong Kong

Volume

14

Issue

5

fYear

1996

fDate

5/1/1996 12:00:00 AM

Firstpage

827

Lastpage

832

Abstract

It is well known that, under the WKB approximation, the refractive-index profile of a graded-index planar waveguide can be calculated from the corresponding effective-index function, which can be found approximately by least-squares fitting of a set of measured effective indexes. In the previous work, effective indexes measured for a particular type of modes (the TE or TM modes) at a single wavelength are used. This requires that the waveguide supports at least three modes of the same type. In this paper, techniques of combining the effective indexes measured for both mode types and at different wavelengths are proposed and demonstrated with examples. With these techniques, single-mode and two-mode waveguides can be profiled

Keywords

WKB calculations; gradient index optics; least squares approximations; optical planar waveguides; optical testing; refractive index; refractive index measurement; WKB approximation; effective index measurement; effective indexes; effective-index function; graded-index planar waveguide; graded-index planar waveguides; least-squares fitting; measured effective indexes; refractive-index profile; refractive-index profiling; single wavelength; single-mode waveguides; two-mode waveguides; Curve fitting; Light sources; Optical device fabrication; Particle measurements; Physics; Piecewise linear approximation; Piecewise linear techniques; Planar waveguides; Tellurium; Wavelength measurement;

fLanguage

English

Journal_Title

Lightwave Technology, Journal of

Publisher

ieee

ISSN

0733-8724

Type

jour

DOI

10.1109/50.495164

Filename

495164