Apparatus and method for enhanced beat note detection

A system, comprising:

• an optical processing system comprising a resonator loop closure optics system and a beat note pickoff system;
• wherein the resonator loop closure optics system is configured to be coupled to an optical resonator coil;
• wherein the optical processing system is configured to receive at least two optical signals;
• and
• wherein the beat not detector pickoff system comprises:
• a first beam splitter;
• a second beam splitter;
• a third beam splitter optically coupled to the second beam splitter;
• a first mirror optically coupled to the first beam splitter and the third beam splitter;
• and
• port optically coupled to the third beam splitter, and is configured to be coupled to an input of a photodiode.

A method, comprising:

• receiving a clockwise (CW) optical signal and the second optical signal includes a counter clockwise (CCW) optical signal;
• injecting the first optical signal and the second optical signal into a resonator loop closure optics system of the optical resonator;
• sampling a portion of the first optical signal and a portion of the second optical signal where the first optical signal and the second optical signal either enter or exit the optical resonator;
• combining the portions of the first optical signal and the second optical signal;
• converting the combined optical signals to an analog electrical signal;
• digitizing the analog electrical signal;
• storing an estimated frequency of a beat signal created by a combination of the CW optical signal and the CCW optical signal;
• and
• using the stored estimated beat signal frequency, digitally phase lock to a frequency of the beat signal.