An all-fiber vortex laser based on orbital angular momentum mode resonance

Abstract

The invention discloses an all-fiber scroll optical laser based on the orbital angular momentum mode resonance, which has a ring cavity structure, and comprises a narrow linewidth pump laser, an optical amplifier, an orbital angular momentum mode generator, a first polarization controller, an optical fiber ring, an optical fiber coupler, a second polarization controller and a scroll optical fiber.The orbital angular momentum mode generator converts the fundamental transverse mode of a single-mode optical fiber into the orbital angular momentum mode of a specific topological charge in a vortexoptical fiber. The fiber coupler can realize the directional coupling of the orbital angular momentum mode in one scroll fiber to the orbital angular momentum mode in another scroll fiber. Vortex optical fiber is a kind of optical fiber which supports orbital angular momentum mode stable transmission. Based on Brillouin nonlinear gain of vortex fiber in ring cavity, the resonant amplification oforbital angular momentum mode in cavity is realized and vortex laser is output. The invention adopts an all-optical fiber structure, has good output vortex laser stability, narrow line width and highorbital angular momentum mode purity.

Description

technical field [0001] The invention relates to the technical fields of fiber lasers and optical communications, in particular to an all-fiber vortex optical laser based on orbital angular momentum mode resonance. Background technique [0002] The vortex beam is a ring-shaped hollow beam with a spiral phase distribution and zero central intensity, and its light field distribution contains a phase factor exp(ilφ) , each photon in the beam carries l The orbital angular momentum of l are called topological charges. different topological charges l The orbital angular momentum mode is orthogonal, which is a new dimension besides the four dimensions of frequency, amplitude, phase and polarization state of the traditional plane wave. Therefore, the use of vortex beams in the field of optical communication will greatly improve the communication System capacity and spectral efficiency. In addition, due to the unique spatial intensity and phase distribution of vortex beams, they ...

AI Technical Summary

Problems solved by technology

Since the mode generated by the fiber coupler is a degenerate linearly polarized (LP) mode, additional stress and adjustment of the polarization state are still required to generate the vortex beam, so the vortex beam generated by the all-fiber laser is completely limited The single-mode fiber-few-mode fiber coupler used has poor beam quality and low mode purity

In addition, the few-mode fiber used in this invention cannot support the stable transmission of the orbital angular momentum mode, resulting in poor stability of the generated vortex beam

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