Open AccessDesign and realization of an all-fiber broadband tunable gain equalization filter for DWDM signals
Author(s) -
R. K. Varshney,
B. Nagaraju,
Aditya Singh,
Bishnu P. Pal,
A. K. Kar
Publication year - 2007
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.15.013519
Subject(s) - wavelength division multiplexing , optics , multi mode optical fiber , optical amplifier , broadband , materials science , optical filter , optical fiber , wavelength , physics , laser
Design and fabrication of a tunable gain equalization filter for dense wavelength division multiplexed (DWDM) signals through erbium doped fiber amplifiers (EDFA) is reported. It is based on a side-polished fiber (SPF) half-coupler block loaded with a displaceable tapered multimode overlay waveguide (MMOW). A simple and accurate normal mode analysis is employed to design this filtering device for its subsequent realization. Equalization of a typical EDFA gain spectrum in the C-band within +/-0.35 dB or even less in the presence of various ITU standard C-band DWDM signal channels is demonstrated under varied operating conditions like add/drop of signals. Tunability of the filter notch is achieved through displacement of the SPF relative to the MMOW.