INJECTION LOCKING OF AN ACTIVELY MODE-LOCKED SEMICONDUCTOR-LASER

We report what is to our knowledge the first observation of synchronou s coherent injection locking of an actively mode-locked extended cavit y semiconductor laser to an external light pulse train. In the tempora l domain, we observed experimentally and verified theoretically a sign ificant narrowing of the output pulse of the mode-locked laser. In the spectral domain, we demonstrated experimentally the narrowing of the output optical spectrum that was due to rejection of spectral componen ts outside the spectral band of the locking pulses. Locking ranges, in the time and the frequency domains, were measured to be similar to 20 0 ps and similar to 5 nm, respectively.