Optical accelerometer system

A method for measuring an external acceleration, the method comprising:

• generating a first optical beam and a second optical beam;
• providing the first optical beam in a variable optical cavity having a cavity length that changes in response to the external acceleration;
• providing the second optical beam in a fixed optical cavity having a fixed cavity length;
• combining the first and second optical beams to generate a beat optical beam;
• providing the beat optical beam to a photodetector to generate a beat voltage that is indicative of a frequency of the beat optical beam;
• and
• comparing the beat voltage with a stable frequency reference voltage to determine a magnitude of the external acceleration.

An optical accelerometer system comprising:

• an integrated optical cavity chip comprising:
• a variable optical cavity waveguide comprising a first gain medium, a first reflective Bragg grating, and a spring-mounted reflector configured to provide a variable cavity length for a first optical beam in response to an external acceleration;
• a fixed optical cavity waveguide comprising a second gain medium, a second reflective Bragg grating, and a reflector that is fixed to a housing of the integrated optical cavity chip to provide a fixed cavity length for a second optical beam;
• a waveguide combiner portion configured to optically combine the variable optical cavity waveguide and the fixed optical cavity waveguide to generate a beat optical beam that is a combination of the first and second optical beams;
• and
• a photodetector configured to monitor the beat optical beam to generate a beat voltage that is indicative of a frequency of the beat optical beam;
• and
• a detection system configured to compare the beat voltage with a stable frequency reference voltage to determine a magnitude of the external acceleration.