Real-time detector for laser beam quality factor M2

Abstract

The invention relates to a laser beam quality M2 factor real time tester, which is formed by a focusing lens, a grid group, a light path adjuster and a CCD, wherein the output end of the CCD is connected with the computer by signal wire; the focus of the focusing lens is f; the dilemma is D; the grid group is a grid light-dividing system which is formed by two oppressed blocks of grid; the grid light-dividing system can divide a beam laser into 3í‡3 strips light beam groups with isocandela; the light path adjuster includes a lens array which is formed by nine reflecting lenses with the corresponding micro-adjusting screw; the distance from the grid group, the light path adjuster to the receiving side of the CCD of the zero-grade diffracted beam of the focusing lens equals to the focus of the focusing lens.

Description

technical field [0001] The invention relates to a detector, in particular to a laser beam quality M 2 Factor real-time detector. Background technique [0002] Laser beam quality M 2 The factor is an important technical index describing the characteristics of the laser, which is directly related to the application efficiency of the laser. m 2 The factor describes the difference between the actual beam and the ideal fundamental mode Gaussian beam, which is defined as [0003] M 2 = π 4 λ d w θ f [0004] Among them, d w and θ f represent the beam waist width and far-field divergence angle of the actual beam, respectively, and 4λ / π is the product of the beam waist width and the far-field divergence angle of the ideal Gaussian beam. Beam quality M 2 The measurement methods of factors ca...

AI Technical Summary

Problems solved by technology

Beam quality M 2 The measurement methods of factors can be divided into two categories according to the principle: one is the Fourier transform method, which simultaneously measures the light field intensity distribution and phase distribution on the beam waist section, and then obtains the spatial spectrum by Fourier transform. Difficult, this method is seldom used; the other is more commonly used, which is the beam width measurement method based on the beam propagation equation, which is also the recommended method of the current ISO standard. There are many ways to use this method to measure the beam quality of the laser beam. However, most methods need to accurately find the beam waist position, and must perform multi-point measurement, so real-time detection cannot be realized

The beam quality M can be measured in real time by using the method of eccentric Fresnel lens group 2 factor, but its design is complicated and the operation is cumbersome. At the same time, different lenses need to be designed for laser beams with different beam qualities, and all measurements cannot be completed by a single lens group.

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