Locking range and stability of injection locked 1.54 micron InGaAsP semiconductor lasers.

Measurements of the intensity of an injection locked 1.54 micron InGaAsP laser are reported. The change in intensity of the locked laser across the locking range is quite asymmetric, with a shape that agrees well with the theory of Lang. A linewidth parameter of alpha = 6 +- 1 was determined from magnitude of the locking range. The injection locked laser was found to be unstable on the high frequency end of the locking range. The physical origin of this instability is explained in terms of a laser intensity change altering the phase of the laser field relative to that of the injected field.