title: Design and realization of an all-fiber broadband tunable gain equalization filter for DWDM signals.
abstract: 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.
authors: R K
authors: RK
authors: Varshney
authors: B
authors: B
authors: Nagaraju
authors: A
authors: A
authors: Singh
authors: B P
authors: BP
authors: Pal
authors: A K
authors: AK
authors: Kar