Method and apparatus for phase detection in a beam steering laser array

摘要

A method and apparatus for measurement of individual phases of beams from a beam steering laser array relative to a reference laser beam. The disclosed method and apparatus is based on the use of a partially reflecting ellipsoidal reflector or dual paraboloidal reflector having two focal areas to make an image of the laser array located in one of the focal areas appear at the other focal area. Illumination of this image with a phase modulated beam from a reference laser coherent with the laser array allows the application of dithering techniques to measure individual phases of beams from array. Any laser beam in the array or a separate laser coherent with the laser array can be used as a reference beam. In addition, the partially reflecting ellipsoidal reflector or dual paraboloidal reflector can provide protection for the beam steering laser array from environmental impacts or damage.

主权项

1. A method for collecting optical information for measurement of individual phases of beams from a laser array, the method comprising:
placing the laser array at a first area of a partially reflecting ellipsoidal or dual paraboloidal reflector to thereby image the laser array at a second area of the partially reflecting ellipsoidal or dual paraboloidal reflector; illuminating the image of the laser array at the second area with a phase modulated beam from another laser coherent with the laser array; disposing a photodetector array ordered in accordance with the image of the laser array outputs at the second area; and detecting the signals from the photodetector array and determining phase differences between beams from the laser array and from the reference beam.