Measurement of depolarization ratio and ultimate limit of polarization crosstalk in silica-based waveguides by using a POLCR

Author

Takada, Kazumasa ; Mitachi, Seiko

Author_Institution

NTT Opto-Electron. Labs., Ibaraki, Japan

Volume

16

Issue

4

fYear

1998

fDate

4/1/1998 12:00:00 AM

Firstpage

639

Lastpage

645

Abstract

A polarization optical low coherence reflectometer (POLCR) is described that enables us to excite only the transverse electric (TE) mode of a test waveguide and to measure its Rayleigh backscatter signal distributions in the TE and transverse magnetic (TM) modes at a spatial resolution of 0.3 mm. The depolarization ratios of silica-based waveguides with relative refractive index differences of Δ=0.45 and 0.75% are obtained as 0.14 and 0.10, respectively, by measuring the bias in the ratio between the distributions in the TM and TE modes of each waveguide. By using the depolarization ratios and the Rayleigh backscatter signal levels, we calculate the ultimate polarization crosstalks to be -53 and -51 dB over 1 km, respectively. The actual polarization crosstalks of previously fabricated waveguides are about 50 dB higher than their ultimate limits for the same length of fiber

Keywords

Rayleigh scattering; backscatter; light polarisation; measurement theory; optical crosstalk; optical planar waveguides; optical testing; optical time-domain reflectometry; refractive index; silicon compounds; 1 km; POLCR; Rayleigh backscatter signal distributions; Rayleigh backscatter signal levels; TE mode; actual polarization crosstalks; depolarization ratio measurement; depolarization ratios; polarization crosstalk; polarization optical low coherence reflectometer; relative refractive index differences; silica-based waveguides; spatial resolution; test waveguide; ultimate polarization crosstalks; Backscatter; Coherence; Crosstalk; Electric variables measurement; Optical polarization; Optical refraction; Optical variables control; Optical waveguides; Tellurium; Testing;

fLanguage

English

Journal_Title

Lightwave Technology, Journal of

Publisher

ieee

ISSN

0733-8724

Type

jour

DOI

10.1109/50.664076

Filename

664076