Power-insensitive Side Locking for Laser Frequency Stabilization

We present a simple modification of the traditional method of locking the laser frequency to the side of an atomic spectral line. We achieve first-order power insensitivity at arbitrary intensity and frequency and in this way eliminate one of the major drawbacks of the traditional method. A similar approach could also be used in locking a laser to a Fabry-Perot cavity.© 2005 Optical Society of America