Beat-note stabilized laser with received-power tracker
AssigneesColdQuanta, Inc., Coldquanta UK Limited
InventorTimothy George Ballance
Life of this patent
Estimating the term…
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.
Claims12
A laser system comprising:
- a laser subsystem having a system optical output to be frequency stabilized and a monitor optical output having a predetermined relationship with the system optical output;
- a frequency reference for providing an optical reference having a reference frequency, the frequency reference comprising:
- a quantum reference;
- a reference laser for directing a reference monitor signal onto the quantum reference, and for providing the optical reference having a reference frequency;
- a photodetector for tracking fluorescence emitted by the quantum reference and producing a corresponding electrical signal;
- and
- a reference frequency controller for receiving the electrical signal from the photodetector and adjusting the reference frequency of the optical reference based on the electrical signal;
- an optical coupler for coupling the monitor optical output and the optical reference to yield an optical beat-note;
- a beat-note detector including:
- a photodetector for converting the optical beat-note to an analog electrical beat-note;
- a digitizer for converting the analog electrical beat-note to a digital electrical beat-note;
- a received-power tracker for extracting received-power data from the analog electrical beat-note, the received-power data corresponding to optical power received by the photodetector;
- and
- a housing enclosing each of the photodetector, the digitizer, and the received-power tracker;
- and
- a frequency controller for regulating a frequency of the system optical output based on the digital electrical beat-notes.
A laser stabilization process comprising:
- generating, using a laser, an output signal and a monitor signal having a predetermined relationship with the output signal;
- directing a reference monitor signal generated by a reference laser onto a quantum reference;
- tracking, in response to directing the reference monitor signal onto the quantum reference, fluorescence emitted by the quantum reference using a photodetector to produce a corresponding electrical signal;
- receiving, using a reference frequency controller, the electrical signal;
- generating, by the reference laser, an optical reference signal based on the electrical signal;
- coupling the monitor signal with the optical reference signal to yield an optical beat-note;
- converting the optical beat-note to an analog electrical beat-note;
- extracting, from the analog electrical beat-note, power-received data regarding optical power received from the optical beat-note;
- digitizing the analog electrical beat-note to yield a digital electrical beat-note;
- and
- frequency stabilizing the output signal based on the digital electrical beat-note.
Dependencies are inferred from the claim text.