Open AccessDirect design of high channel-count fiber Bragg grating filters with low index modulation
Author(s) -
Hui Cao,
Javid Atai,
Xuewen Shu,
Guojie Chen
Publication year - 2012
Publication title -
optics express
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.394
H-Index - 271
ISSN - 1094-4087
DOI - 10.1364/oe.20.012095
Subject(s) - fiber bragg grating , optics , modulation (music) , refractive index , materials science , channel spacing , channel (broadcasting) , reduction (mathematics) , modulation index , wavelength division multiplexing , optical fiber , physics , telecommunications , computer science , mathematics , acoustics , power (physics) , pulse width modulation , wavelength , geometry , quantum mechanics
a novel method for designing high channel-count fiber Bragg gratings (FBGs) is proposed. For the first time, tailored group delay is introduced into the target reflection spectra to obtain a more even distribution of the refractive index modulation. This approach results in the reduction of the maximum refractive index modulation to physically realizable levels. The maximum index modulation reduction factors are all greater than 5.5. This is a significant improvement compared with previously reported results. Numerical results show that the thus designed high channel-count FBG filters exhibit superior characteristics including 30 dB channel isolation, a flat-top and near 100% reflectivity in each channel.