Open AccessInfluence of cladding-mode coupling losses on the spectrum of a linearly chirped multi-channel fiber bragg grating
Author(s) -
Hongpu Li,
Yuusaka Nakamura,
Kazuhiko Ogusu,
Yunlong Sheng,
Joshua E. Rothenberg
Publication year - 2005
Publication title -
optics express
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.394
H-Index - 271
ISSN - 1094-4087
DOI - 10.1364/opex.13.001281
Subject(s) - cladding (metalworking) , optics , cladding mode , fiber bragg grating , materials science , channel spacing , long period fiber grating , coupled mode theory , grating , refractive index , reflection (computer programming) , optical fiber , wavelength division multiplexing , physics , graded index fiber , polarization maintaining optical fiber , fiber optic sensor , wavelength , computer science , metallurgy , programming language
Influence of cladding-mode coupling losses on the spectrum of multi-channel fiber Bragg grating (FBG) has been numerically investigated on the basis of the extended coupled-mode equations. It has been shown that there exists a reflection slope in the spectrum of both the intra- and inter-channels due to the existences of the cladding modes. This slope could be larger than 1 dB when the induced index change is about 3x10-3, which makes the channels considerably asymmetric. For comparison, a 39-channel linearly chirped FBG with a channel spacing of 0.8 nm and a chromatic dispersion of -850 ps/nm has been designed and fabricated. The experimental results show good agreement with the numerical ones. Finally, one method to pre-compensate the reflection slope within the intra-channels has been proposed and successfully demonstrated.