Sidelobe-free angle-selection laser filter

Abstract

The invention discloses a sidehole-free angle-selection laser filter. The filter comprises a first volume Bragg grating for diffracting incident light for the first time and a second volume Bragg grating for diffracting diffracted light from the first volume Bragg grating for the second time, wherein vectors of the first and second volume Bragg gratings are parallel, and a large diffraction level of the first volume Bragg grating corresponds to the diffraction zero value of the second volume Bragg grating. The sidehole-free angle-selection laser filter of the invention can effectively overcome the sidehole defect of a common angle-selecting laser filter, and can realize space filtering in a higher quality; the structure is compact; and low-pass filtering can be excellently carried on different spectral components, and bearable laser power is higher.

Description

technical field [0001] The invention relates to the technical field of optical filtering, in particular to a sidelobe-free angle-selective laser filter with diffraction sidelobe suppression and angle-selective filtering capabilities. Background technique [0002] Volume Bragg gratings have revolutionized beam transmission and spatial filtering techniques due to their excellent angular and spectral selectivity. The two-dimensional angle-selective spatial filtering technology based on the volume Bragg grating is different from the traditional spatial filtering technology. Since the spatial filtering is implemented directly in the near field of the strong laser beam transmission, the focusing process is omitted, so many inherent defects of the traditional spatial filtering are fundamentally resolved. . At the same time, it can effectively eliminate the influence of medium and high frequency modulation on the beam, reduce the cut-off frequency and low frequency loss of traditio...

AI Technical Summary

Problems solved by technology

The residual spatial frequency is negligible at low power, but it is a great defect in the field of advanced high power laser devices

This means that these medium and high frequency modulations may still be amplified due to nonlinear effects during the amplification process, which will damage the beam quality and threaten the safety and stability of the entire laser system.

On the other hand, due to the mutual limitation among the structural parameters of the volume Bragg grating, the first-order diffraction null width of a single volume Bragg grating is usually not small enough, which seriously limits the cut-off frequency of the angle-selective filter.

Images