High-precision laser divergence angle parameter calibration device

Abstract

The invention discloses a high-precision laser divergence angle parameter calibration device. A to-be-tested laser (1) is focused through a lens (6) after being reflected through an optical flat (3) and a spectroscope (2); a converge light is divided into two testing light paths of transmission and reflection after passing through a beam splitter (7); when a focus light spot not exceeds a photosurface of a CCD camera (8), the testing light path is the transmission light path; the CCD camera (8) is located at a lens focal plane position, and the focal spot diameter is calculated by a formula (2); conversely, the testing light path is reflecting light path; a ground glass screen (9) is located at the lens focal plane, an imaging system (10) images the light spot on the ground glass screen (9); the focal spot diameter is calculated by the formula (2). A calibration parameter fn is substituted; a formula (3) is used for calculating the divergence angle of the to-be-tested laser; according to the established confusion disc model base, the collected focal spot is performed with confusion disc spreading and superposition; thus the measurement uncertainty introduced by aberration and light path imbalance of the lens (6) is evaluated.

Description

technical field [0001] The invention belongs to the field of measurement and measurement of laser divergence angle parameters, and relates to a high-precision calibration device for laser divergence angle parameters. Background technique [0002] The divergence angle is the core parameter of the laser, and it is also an important parameter to evaluate the beam quality. The general definition of the far-field divergence angle of the Gaussian beam is: in the far field (the transmission distance tends to infinity), the amplitude of the Gaussian beam decreases to the center maximum value 1 / The angle between e and the central axis of transmission. [0003] The mainstream measurement devices for laser divergence angle parameters are as follows: image 3 As shown, the laser to be measured is focused with a focusing lens, and the spot diameter d on the focal plane of the lens is measured by a detector. The spot diameter is usually calculated according to the definition of 86.5% of ...

AI Technical Summary

Problems solved by technology

[0011] The purpose of the present invention is to provide a laser divergence angle parameter that can measure 0 to 20mrad in view of the shortcomings of existing laser divergence angle parameter measurement technology equipment, such as many measurement uncertainty components and incomplete uncertainty component analysis. The degree of certainty is less than 5%, and a measuring device that can realize high-precision measurement of laser divergence angle parameters at a low cost

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