A system for compensating for phase variance of a laser source comprising: a laser output path comprising: a delay line configured to delay an output of the laser source, and a phase modulator configured to receive an output of the delay line and an output of a phase corrector; and a phase error path comprising: an optical phase detector configured to determine an estimated phase error of the laser source, wherein the optical phase detector comprises: a splitter configured to receive the output of the laser source and output a first output and a second output; a delay line configured to delay the first output, wherein the delay line has a length less than one third of the coherence length of the laser source; and a phase detector configured to determine a phase difference between the delayed first output and the second output, wherein the optical phase detector outputs the phase error derived from the phase difference as the estimated phase error, and the phase corrector configured to receive the output of the optical phase detector and determine a phase correction as the output of the phase corrector, wherein the phase modulator outputs a phase corrected laser output. a laser output path comprising: a delay line configured to delay an output of the laser source, and a phase modulator configured to receive an output of the delay line and an output of a phase corrector; and a delay line configured to delay an output of the laser source, and a phase modulator configured to receive an output of the delay line and an output of a phase corrector; and a phase error path comprising: an optical phase detector configured to determine an estimated phase error of the laser source, wherein the optical phase detector comprises: a splitter configured to receive the output of the laser source and output a first output and a second output; a delay line configured to delay the first output, wherein the delay line has a length less than one third of the coherence length of the laser source; and a phase detector configured to determine a phase difference between the delayed first output and the second output, an optical phase detector configured to determine an estimated phase error of the laser source, wherein the optical phase detector comprises: a splitter configured to receive the output of the laser source and output a first output and a second output; a delay line configured to delay the first output, wherein the delay line has a length less than one third of the coherence length of the laser source; and a phase detector configured to determine a phase difference between the delayed first output and the second output, a splitter configured to receive the output of the laser source and output a first output and a second output; a delay line configured to delay the first output, wherein the delay line has a length less than one third of the coherence length of the laser source; and a phase detector configured to determine a phase difference between the delayed first output and the second output, wherein the optical phase detector outputs the phase error derived from the phase difference as the estimated phase error, and the phase corrector configured to receive the output of the optical phase detector and determine a phase correction as the output of the phase corrector, wherein the phase modulator outputs a phase corrected laser output. <EOS>