Adjustable bandwidth dispersionless bandpass FBG optical filter

Abstract

A bandpass optical filter, based on fiber Bragg gratings, is presented in which the bandwidth of a Gaussian spectrum can be continuously adjusted, whilst maintaining near zero group delay slope over the filter bandwidth. The device is also wavelength tunable and the spectral profile is selectable by appropriate grating design. This novel device is employed in a 2R-regenerator, enabling data rate reconfiguration and wavelength conversion, with negligible phase distortion. It will find application wherever a dispersionless reconfigurable bandpass optical filter is required.