35-GHz intrinsic bandwidth for direct modulation in 1.3-/spl mu/m semiconductor lasers subject to strong injection locking

Significant enhancement in modulation bandwidth of semiconductor lasers subject to strong optical injection is experimentally and theoretically studied. At least two folds of improvement is achieved under study. By using an optical probing method, a modulation bandwidth of 35 GHz that is free from electrical parasitic effects is observed in the injection-locked laser system. The achieved bandwidth approaches the maximum modulation bandwidth set by the K factor for the free-running laser. Discussions are presented for an even larger modulation bandwidth using the injection-locking technique.