Two-dimensional angle selecting laser filter

Abstract

The invention discloses a two-dimensional angle selecting laser filter. The two-dimensional angle selecting laser filter comprises a first volume Bragg grating for performing first-time diffraction on incident light and a second volume Bragg grating for performing second-time diffraction on the diffracted light emerging from the first volume Bragg grating, wherein grating vectors of the first volume Bragg grating and the second volume Bragg grating are mutually orthogonal. The two-dimensional angle selecting laser filter is completely different from a traditional spatial filter provided with a lens and a pin hole, and the high-quality spatial filtering is directly achieved in a laser transmission near field. The two-dimensional angle selecting laser filter is compact in structure, has excellent lowpass filtering capacity on spectral components and is high in bearable laser power.

Description

Technical field [0001] The invention relates to the technical field of optical filtering, in particular to a two-dimensional angle selective laser filter with both angle selective filtering capability and low frequency loss rate. Background technique [0002] Many boundary conditions in the overall design and construction of advanced laser devices directly limit their output capabilities. One is the "power limited condition" of advanced laser devices; the second is the energy limited condition of advanced laser devices, that is, the damage threshold of optical components under long pulse (≥3ns) working conditions. The light intensity distribution of an actual beam cannot be completely uniform and smooth, and it always has more or less irregular modulation and fluctuations. Usually before the light beam self-focusing occurs, because some small self-induction lenses are formed at these modulations and fluctuations, these modulations and fluctuations make the beam self-focusing loc...

AI Technical Summary

Problems solved by technology

However, the application of traditional spatial filters in advanced laser devices has great limitations: in addition to the difficulty of alignment and high cost, high-power laser focusing may cause "hole blocking effect" or even damage and produce a new needle. The hole can also ionize the air in the external optical path, affect the beam quality, and even destroy the laser system; there is also the growth of nonlinear effects after focusing, etc.

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