Abstract: With the increasing application of laser, the quality measurement of laser beams with metersacle large-aperture is of important research value. To avoid the influence of atmosphere, the wavefront measurement method is gernerally used to directly measure the quality of laser beams with meter-scale large-aperture at the outlet of laser systems. In order to achieve accurate measurement, it is necessary to calibrate the zero point of the meter-scale large-aperture measurement system first. A scanning calibration method for the large-aperture measurement system is proposed in this work using a small aperture calibration light source. The errors of the beam spot centroid shift caused by residual errors of the parallelism of the calibration light source under different scanning mode are analyzed, and the influence of residual errors of the parallelism of the calibration light source on the measurement accuracy in different scanning mode is simulated and analyzed. According to the wavefront restoration results, the unidirectional scanning mode is selected, and it is specified that the residual error of the parallelism of the calibration light source is not greater than 5 μrad when the aperture of scale validation model system is 127 mm, while the residual error of the parallelism of the calibrated light source for the actual measurement system with 1.27 m aperture is not greater than 0.5 μrad.

Key words: laser technology, beam quality, measurement system of large - aperture meter-scale, zero calibration, parallelism residual error