Optimum linear pulse compression of a gain-switched 1.5 μm DFB laser

We report on pulse compression measurements of a 1.5 μm gain-switched strained multi-quantum well distributed feedback semiconductor laser. Experiments with eight normal dispersion fiber lengths show that the optimum compression may be achieved at a dispersion value about half of the one usually calculated using a gaussian pulseshape model. Pulse compression measurements are well reproduced by a simple model involving rate equations. Effective linewidth enhancement factors, /spl alpha//sub eff/, deduced from this model reveal increasing values with pumping conditions. We show that this nonlinear behaviour is in agreement with an intensity dependence of /spl alpha//sub eff/.