Abstract: In one general aspect, a non-transitory computer-readable storage medium can be configured to store instructions that when executed cause a processor to perform a process. The process can include producing a segment of a laser signal where the segment of the laser signal has a duration, and producing a first reference signal based on the laser signal. The process can include calculating a first phase deviation corresponding with a first portion of the duration based on the first reference signal, and producing a second reference signal based on the laser signal. The process can include calculating a second phase deviation corresponding with a second portion of the duration based on the second reference signal, and calculating a phase deviation of the segment of the laser signal based on a combination of the first phase deviation and the second phase deviation.