Active control of a diode laser with injection locking

Injection locking of a diode laser is essential in a majority of fields including laser spectroscopy, laser cooling and trapping and optical communication, and especially critical when the laser power budget is limited. However, the stability of injection locking is a major obstacle, since environmental variations and laser current drifts can frequently cause the injected slave laser out of lock. In this poster, we introduce a novel active stabilization scheme for injection locking by simply using a narrow laser-line filter and a photodiode. Based on characteristic response of the reflected power from the filter versus spectral modes, high spectral mode purity and low intensity noise can be simultaneously maintained by a proper feedback to the laser current. This method is already used in the daily production of Bose-Einstein condensates of erbium atoms in our lab. Besides, our method eliminates the usual need of complicated and bulky devices, such as Fabry-Perot interferometers or wavemeters, to monitor the state of injection locking. Moreover, it favors miniaturized and integrated modules for the active control of injection locking of diode lasers, which would greatly simplify versatile applications of laser injection locking.