Abstract: A laser system provides a system output signal and a monitor signal with a predetermined phase and/or frequency relationship to the system output signal. The monitor signal is combined with a reference frequency to yield an optical beat-note. A telecom optical transceiver (e.g., an SFP or an SFP+ module) is used to convert the optical beat-note to an analog electrical beat-note. The transceiver can extract received-power information from the analog electrical beat-note and digitize the analog electrical beat-note to yield a digital electrical beat-note. The digital electrical beat-note can be used to stabilize the laser and the system output signal by phase or offset locking.

Abstract: A spectroscopy system is described. The spectroscopy system includes a cell, a photodiode, and mirrors. The cell has walls forming a chamber therein. The chamber is configured to receive laser signal(s) and retaining a vapor therein. The vapor fluoresces in response to the laser signal(s). The mirrors are configured to direct fluorescent light from the vapor toward the photodiode. In some embodiments, the spectroscopy system is incorporated with a photonic integrated circuit.