Method for producing highly accurate frequency and FM of a laser

A method for controlling the frequency and phase of a laser, comprising:

• sampling an output of the laser;
• providing the sampled output to a first modulator;
• modulating the sampled output with a first frequency in the first modulator;
• delaying the modulated output from the first modulator;
• combining the delayed modulated output from the first modulator with the sampled output, to generate a combined output;
• developing quadrature components based on the combined output;
• applying an arctangent function to the quadrature components;
• correlating the output of the arctangent function with a first reference signal to obtain a measure of peak frequency deviation of the laser;
• correlating the output of the arctangent function with a second reference signal to obtain a measure of phase offset, wherein the second reference signal is 90 degrees out of phase with the first reference signal;
• integrating the output of the arctangent function to obtain a mean frequency of the laser;
• comparing the obtained peak frequency deviation and the obtained phase offset, with respective set point values to generate frequency deviation error and phase offset error signals;
• and
• adjusting a control signal for modulating the laser, with the frequency deviation error signal, the phase offset error signal, and the obtained mean frequency.

A method for controlling the frequency and phase of a laser, comprising:

• sampling an output of the laser;
• providing the sampled output to a first modulator;
• modulating the sampled output with a first frequency in the first modulator;
• delaying the sampled output;
• combining the modulated output from the first modulator with the delayed sampled output, to generate a combined output;
• developing quadrature components based on the combined output;
• applying an arctangent function to the quadrature components;
• correlating the output of the arctangent function with a first reference signal to obtain a measure of peak frequency deviation of the laser;
• correlating the output of the arctangent function with a second reference signal to obtain a measure of phase offset, wherein the second reference signal is 90 degrees out of phase with the first reference signal;
• integrating the output of the arctangent function to obtain a mean frequency of the laser;
• comparing the obtained peak frequency deviation and the obtained phase offset, with respective set point values to generate frequency deviation error and phase offset error signals;
• and
• adjusting a control signal for modulating the laser, with the frequency deviation error signal, the phase offset error signal, and the obtained mean frequency.