Measurement method of beam quality factor β for high energy laser

The high energy laser beam quality factor measurement system is used for state debugging as well as comprehensive performance parameters diagnosis of laser system, while these parameters can evaluate the laser output performance and the far-field spot focusing ability of the laser system. Aiming at the defect that the beam quality factor close to the diffraction limit occupies too few pixels in the area array detectors, a measurement method was proposed based on microscopic magnification with scanning slit. In addition, a verification scheme using the combination of fixed phase and colimator light source was designed to verify beam quality factor accuracy, the scheme proves the measurement uncertainty of our device is less than 10%.