GENERATION OF OVER 140-NM-WIDE SUPER-CONTINUUM FROM A NORMAL DISPERSION FIBER BY USING A MODE-LOCKED SEMICONDUCTOR-LASER SOURCE

The super-continuum (SC) spectrum flatly broadened over 140-nm 10-dB b andwidth is generated by using a mode-locked semiconductor laser as a pulse source at 1550 nm. In our SC generation system, nearly Fourier-t ransform limited 0.9-ps pulses obtained through linear and nonlinear p ulse compression are incident on a dispersion-flattened fiber having a small normal group-velocity dispersion. While the pulses pass through the normal dispersion fiber, the pulse waveform is adapted to suit th e accumulation of a Linear chirp, which leads to the flat and wide-ban d SC spectrum.