Fiber laser light coherent combination system

A fiber laser light coherent combination system, comprising:

• a modulator module configured to receive a plurality of sub-beams and a reference beam split from a beam, perform a phase modulation on corresponding sub-beams according to pseudo-random sequences, and perform a frequency shift on the reference beam according to a set frequency, wherein each of the sub-beams is corresponding to one of the pseudo-random sequences, the pseudo-random sequences are orthogonally independent from each other, and a 2m-th item and a (2m−1)-th item in each of the pseudo-random sequences have different values, wherein m is a positive integer;
• a fiber laser light amplifier module configured to perform a power amplification on the plurality of sub-beams after the phase modulation;
• a laser light collimation emission module configured to collimate and output the reference beam after the frequency shift and the plurality of sub-beams after the power amplification;
• a combination sampling module configured to perform a coherent combination of all of the sub-beams and the reference beam which are collimated and outputted, and convert signal light obtained by the coherent combination into an electrical signal;
• and
• a digital phase modulation and demodulation module configured to receive the electrical signal, perform a phase demodulation on the electrical signal according to the set frequency and each of the pseudo-random sequences, obtain a phase difference between each of the sub-beams and the reference beam, and output a phase compensation control signal,
• wherein the modulator module is further configured to perform a phase compensation and locking on each of the sub-beams according to the phase compensation control signal, so that a coherence enhancement occurs during the coherent combination of all of the sub-beams in the combination sampling module;
• wherein the modulator module comprises:
• a signal source configured to generate a modulation signal of the set frequency;
• an acousto-optic modulator configured to perform a frequency shift on the reference beam according to the modulation signal;
• and
• a plurality of phase modulators configured to perform a phase modulation on the corresponding sub-beams according to the pseudo-random sequences, and perform phase locking on each of the sub-beams according to the phase compensation control signal.