Optical detector for measuring respective phases of multiple beams apparatus and method

A method for measuring phases of beams from a laser/laser amplifier array relative to a reference beam, comprising:

• illuminating a mask defining apertures therein with the reference beam to create reference beams as the reference beam passes through the mask;
• modulating one of (a) beams from the array and (b) the reference beams;
• combining the beams from the array with the reference beams on a photodetector to generate a signal;
• measuring the signal from the photodetector;
• calculating the respective beam phases for beams in the array relative to the reference beam in response to the measured signal from the photodetector.

In a system comprising a source of coherent laser beams forming an array, a source of a reference laser beam coherent with the array laser beams, and an optical detector for measuring respective phase differences between the array laser beams and the reference laser beam, comprising:

• a mask defining apertures therein and positioned in the reference laser beam to create reference laser beams as the reference beam passes through the mask;
• a photodetector receiving the beams from the laser array and the beams from the mask to generate a composite signal;
• and
• processing circuitry responsive to the composite signal from the photodetector for generating respective signals representing the phase differences of the individual laser beams from the reference laser beam.

A method for measuring phases of beams from a coherent laser/laser amplifier array relative to a reference beam, comprising:

• illuminating a mask defining apertures therein with the reference beam to produce reference beams emanating through the apertures in the mask;
• modulating one of (a) the beams in the array of laser beams and (b) the reference laser beams emanating through the apertures in the mask;
• combining the array beams with the reference beams on a photodetector to develop a signal;
• measuring the signal from the photodetector;
• calculating the beam phases for beams in the array relative to the reference beams in response to the measured total signal from the photodetector.