Saturable Spectroscopy
Laser Lock Module

The AOSense Laser Lock Module (LLM) provides a compact, mechanically-robust laser frequency reference. An optional add-on for the AOSense Servo and Integrated Laser Controller (SILC), the LLM provides a convenient long-term frequency reference to stabilize a laser for atomic, molecular, or optical applications. Insensitivity to environmental magnetic field and temperature variations, a sturdy design, and fiber-coupled input enable its use in both field and laboratory systems. The LLM provides both a DC output to monitor power variations and an AC-coupled output that enables locking to a high-SNR error signal. Simply plug the LLM into an AOSense SILC and send in fiber-coupled light to view the absorption spectrum, with or without background subtraction; optionally modulate the laser polarization or frequency (for example, with an EOM) to create a high-quality error signal. The long-term frequency drift of the AOSense LLM has been characterized with a GPS-synchronized frequency comb, and has seen use in a variety of atomic physics applications that demand high performance in a small package. The LLM comes standard with either rubidium or cesium; other species are available on request.