M.Subanya, D. Helena Margaret
A hybrid model is proposed in order to use the design of compensating semiconductor optical amplifiers (SOAs) nonlinearity by adjusting cavity dispersion in a SOA-fiber ring mode-locked laser. It is predicted that, once the cavity dispersion is correctly adjusted, the mode-locked pulses of 10 ps width will become distortion-free Gaussians, with their time-bandwidth product(TB)very close to the fundamental Gaussian limit(TB=1/2)using root mean-square definition. This effects related to band-pass filter are shown as well. Our results highlight the ambiguity of TB using full-width at half-maximum (FWHM) definition. As result, the generally adopted concept of transform-limited pulse in its FWHM description may be misleading. Keywords- Optical pulses, semiconductor fiber ring laser, transform-limited pulse, ultrafast optics, pulse generation.