Method for producing highly accurate frequency and FM of a laser

An apparatus for modulating the frequency and phase of a laser, comprising:

• a delay-line inteferometer for sampling the laser, the interferometer including a frequency offset in at least one leg of the optical path of the interferometer;
• an intermediate frequency processor for filtering and converting the output of the interferometer;
• a quadrature module for receiving an output of the intermediate frequency processor, and extracting quadrature components from the received output;
• an arctangent function module connected to convert the extracted quadrature components to a phase measure that is proportional to the frequency of the laser;
• a plurality of correlator circuits connected to extract a modulation peak deviation, an average frequency of the laser, and a modulation phase error from the phase measure;
• and
• at least one feedback loop for controlling the laser based on the extracted modulation peak deviation, the extracted average frequency of the laser, and the extracted modulation phase error.