Method for simultaneously achieving laser frequency doubling and line aggregation in optical superlattice

Abstract

The invention discloses a method for simultaneously achieving laser frequency doubling and line aggregation in an optical superlattice. The method comprises the following steps that 1, an upper inclined domain structure and a lower inclined domain structure with the same period are designed in the superlattice, and are distributed symmetric about the crystal light passing direction; 2, when fundamental waves are vertically shot into the superlattice in an incident mode, the upper half portion of the superlattice can generate laser frequency doubling waves bent downwards, the lower half portion of the superlattice can generate laser frequency doubling waves bent upwards, the laser frequency doubling waves generated by the upper half portion and the laser frequency doubling waves generated by the lower half portion are the same in bending angle and strength, and accordingly, a line focusing interference pattern similar to an axicon can be generated on the overlapped area of the upper half portion and the lower half portion; 3, after lasers enter the superlattice, reciprocal lattice vectors provided by the domain structures of the superlattice can compensate for wave vector mismatching between fundamental waves and the laser frequency doubling waves, and a triangle with matched wave vectors is formed. Frequency doubling of lasers and line aggregation are achieved simultaneously through the periodically-symmetric and inclined domain structures in the optical superlattice.

Description

technical field [0001] The invention relates to the intersection field of nonlinear optics and superlattice material technology, in particular to a method for simultaneously realizing laser frequency doubling and line gathering in an optical superlattice. Background technique [0002] In practical applications such as laser heat treatment, laser cutting, etc., line-focused beams are often required. In linear optics, an axicon is usually used to achieve line focusing of a light beam. The axicon bends the incident beam at an equal angle, and cancels the diffraction effect through the interference effect of light waves, so that the generated outgoing beam has the characteristics of approximately diffraction invariance within a certain distance, that is, the line focusing of the beam. However, because the axicon is a pyramidal structure, it has the disadvantages of high processing difficulty and high cost, and the frequency conversion of the laser cannot be realized. [0003] ...

AI Technical Summary

Problems solved by technology

Although it has the advantage of low cost, due to the inherent defects in the principle, there will be a large number of "void" areas with low light intensity in the interference area of ​​the Fresnel axicon, and the quality of the line focused beam is not as high as that of the traditional axicon.

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