Simple laser frequency locking based on Doppler-free magnetically induced dichroism

We present a simple and reliable optical setup for active stabilization of a diode laser. The method combines Doppler-free spectroscopy and magnetically induced dichroism in atomic vapor. The long- and short-term stability is achieved using a simplified optical and laser setup. We apply the setup to stabilize an external-cavity diode laser to the D2 atomic resonance in potassium vapor. With the laser locked we attain long-term stabilization to the atomic line with the reduction of laser frequency jitter down to 0.5 MHz on a 50 ms timescale.