A Compact Setup of Saturated Absorption Spectroscopy for Diode Laser Frequency Stabilization

A novel setup of saturated absorption spectroscopy (SAS) is presented. It is based on laser reflections at surfaces of a sample vapor cell. It only needs one cell and one photodiode and is more compact than conventional setups of SAS. Its spectrum is similar to a conventional SAS. The frequency stabilization performance of an external-cavity diode laser with this setup is investigated. A frequency stability of 1.1×10^-11 is achieved at an averaging time of 60 s in the Allen variance measurements.