A dispersionless and bandwidth-adjustable FBG filter for reconfigurable 2R-regeneration

We present a bandwidth-adjustable filter that enables reconfiguration of the bit rate of optical subsystems. This filter is bandwidth-adjustable, wavelength-tunable, and maintains zero dispersion as the bandwidth and wavelength are varied. It also has a transmission spectrum which is Gaussian, to shape Gaussian pulses in the time domain. The ability of the bandwidth-adjustable filter to enable bit-rate reconfiguration is demonstrated in an optical regenerator based on self-phase modulation. The bandwidth-adjustable filter replaces the fixed-bandwidth filter usually used in this kind of regenerator, and enables optical regeneration at both 40 and 80 Gb/s.