Adjustable EDFA Gain Equalization Filter for DWDM Channels Based on a single LPG excited by Flexural Acoustic Waves
; Oliveira, R.A.
; Pohl, A.
Optics Communications Vol. 285, Nº 18, pp. 3770 - 3774, August, 2012.
ISSN (print): 0030-4018
Journal Impact Factor: 1,552 (in 2008)
Digital Object Identifier: 10.1016/j.optcom.2012.05.045
A fast adjustable gain equalization filter for dense wavelength division multiplexing (DWDM) system is reported. The method is based on a single long period fiber grating (LPG) which is excited by means of flexural acoustic waves. The equalization of a typical erbium doped fiber amplifier (EDFA) gain spectrum with a gain flatness of <0.3 dB over a 32 nm bandwidth is demonstrated. The filter adjustment is obtained by choosing different acoustic loads applied to the acousto-optic modulator, which presents a switching time of ∼17 μs. A maximum power penalty of 0.84 dB, relatively to the back-to-back signal, was achieved.