Diode Laser Optically Injected by Resonance of a Monolithic Cavity

We demonstrate a self-injection locking extended cavity diode laser (ECDL) using resonant optical feedback from the p-polarization of a monolithic folded Fabry–Perot parallel cavity (MFC). The full width at half maximum of the MFC resonance is 31 MHz. With the help of a narrow-linewidth reference laser, the linewidth of the ECDL is measured to be about 7 kHz. The frequency of the laser could be tuned at 160 MHz with an amplitude of 40 V by a PZT mounted on the monolithic cavity and the voltage tuning coefficient is about 4 MHz/V.