  We discuss our recent progress in iimproving the phase noise of a
semiconductor laser using self-injection locking of to a mode of a high-Q
whispering gallery mode resonator. Locking efficiency is analyzed for
semiconductor distributed feedback (DFB) as well as Fabry-Perot (FP) lasers
operating at 690nm, 1060nm, 1550nm, and 2000nm. Instantaneous linewidth below
300 Hz is realized with telecom DFB lasers. Tunability of the lasers is
demonstrated. Commercially available packaged "plug-and-play" devices are
manufactured.
