Frequency Stabilization of the Zeeman Laser

The intensity crossover region with cavity tuning between oscillations on two orthogonally circularly polarized axial modes of a Zeeman laser has been used to stabilize these oscillation frequencies with respect to the center of the atomic transition. In contrast to previously proposed stabilization schemes this method allows operation over a wide range of frequencies off the center of the atomic transition, providing step and vernier tuning. The stabilization method has been successfully applied to the 0.633-μ and 1.153-μ He–Ne and 2.65-μ Xe lasers. A frequency stability of one part in 1010 was obtained with the 2.65-μ Xe laser.