Laser far-field focal spot high-precision dynamic diagnosis device and method

Abstract

The invention provides a laser far-field focal spot high-precision dynamic diagnosis device and method, and aims to overcome the defects that the prior art is low in resolution ratio and large in error.The dynamic diagnosis device comprises a single mode fiber laser device, a collimating mirror, an iris diaphragm, a beam splitter, a sampling mirror, a beam shrinking and expanding system, a reflective mirror, a multi-channel binary optical element and a CCD detector which are sequentially arranged on the same optical path.The dynamic diagnosis device further comprises a reference integrating sphere power meter arranged on the reflecting optical path of the beam splitter, a measurement integrating sphere power meter arranged on the reflecting optical path of the reflective mirror and a control computer connected with the reference integrating sphere power meter, the measurement integrating sphere power meter and the CCD detector at the same time.Far-field focal spot diagnosis of laser beams in different calibers can be achieved; the dynamic diagnosis device has the advantages of being high in accuracy and stability, and measurement results are high in confidence coefficient.

Description

technical field [0001] The invention belongs to the field of optics, and relates to a high-precision dynamic diagnosis device and a diagnosis method for a laser far-field focal spot based on a multi-channel binary optical technology and a phase recovery method. Background technique [0002] The intensity distribution of the laser far-field focal spot is an important indicator of the quality of the laser beam, and it is also the main parameter that characterizes the ability of the laser beam to enter the hole in the high-energy laser system. The far-field distribution of the laser determines the focusability of the beam and indirectly reflects the wavefront condition. Accurate measurement of the far-field focal spot is crucial to the correct evaluation of beam quality evaluation parameters such as beam quality β factor and encircling energy ratio. There are two main difficulties in the measurement of the high-energy laser far-field focal spot: (1) the intensity distribution ...

AI Technical Summary

Problems solved by technology

The disadvantages of this method are: (1) The calculation of the wavefront slope uses a first-order linear approximation, that is, sinθ≈tanθ≈θ, which affects the accuracy of wavefront measurement; (2) Since the average slope of the distorted wavefront in the sub-aperture is measured, the It is considered that the measured wavefront is approximately composed of plane waves in many sub-apertures, the detailed information of the distorted wavefront in the sub-aperture is ignored, and the resolution of the wavefront measurement is not high; (3) using the Shack-Hartmann wavefront sensor The obtained laser near-field light intensity distribution is also limited by the number of microlens arrays, and the resolution is not high; (4) The laser far-field focal spot reconstruction accuracy is affected by the Shaker-Hartmann wavefront sensor system error

Although it is generally believed that the solution of phase recovery is unique, different algorithms will have a great impact on the accuracy and convergence speed of the solution.

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