8-cavity orbital angular momentum mode mode-locked fiber laser device

Abstract

The invention discloses a 8-cavity orbital angular momentum mode mode-locked fiber laser device. The laser device includes a fundamental mode pump source, a first polarization controller, an orbital angular momentum mode generator, a wavelength division multiplexer, a vortex gain fiber, a second polarization controller, a first fiber coupler, a second fiber coupler, a polarization isolator, a third polarization controller and a vortex fiber. Based on fiber mode separation and optimization design, generation and stable transmission of a specific order orbital angular momentum mode in a resonantcavity and an output end can be guaranteed by the vortex fiber device; based on the same-order mode pumping mechanism and the filter mode effect of the resonant cavity, the gain of the signal light of the same-order orbital angular momentum mode in the resonant cavity is maximized, furthermore, the orbital angular momentum mode mode-locked laser output is obtained under the non-linear magnifyingring mirror mode-locking technology. The laser device is advantaged in that based on the single-mode direct resonance mechanism in the 8-shaped cavity, the outputted orbital angular momentum mode mode-locked laser has high mode purity and good beam quality.

Description

technical field [0001] The invention relates to the field of laser technology, in particular to an 8-cavity orbital angular momentum mode-locked fiber laser. Background technique [0002] A vortex beam is a field distribution with a helical phase term exp( ilφ ) of a beam in which each photon carries lh Orbital angular momentum ( l is the topological charge, φ is the azimuth angle, h is Planck's constant), and has the characteristics of annular light field distribution and spiral phase singularity. These unique properties make it widely used in the fields of material processing, optical tweezers, high-resolution imaging, fiber optic sensing, and fiber optic communication. However, these application prospects put forward higher requirements on the output peak power, stability, mode purity and bandwidth of the vortex beam. Mode-locked pulsed lasers can meet such requirements due to their advantages such as narrow pulse width, high peak power, and wide spectral width. A...

AI Technical Summary

Problems solved by technology

The traditional single-mode fiber only supports the transmission of the fundamental transverse mode. Due to the weak waveguide approximation in the traditional few-mode fiber or multimode fiber, the high-order vector transverse modes with similar propagation constants are degenerated into linear polarization modes, which cannot meet the requirements of the orbital angular momentum mode. Stable transmission in optical fiber

Therefore, the transmission of OAM mode-locked pulses converted from the output of traditional mode-locked fiber lasers is unstable

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