Method for suppressing stimulated Raman scattering, high-power fiber laser and all-solid-state microstructured fiber

Abstract

The invention provides a method for suppressing stimulated Raman scattering, a high-power fiber laser and an all-solid-state microstructure fiber. The all-solid-state microstructure fiber comprises a core and a microstructure cladding, wherein the core is a solid core and the microstructure The cladding is wrapped around the periphery of the fiber core, and the microstructure cladding is located on the germanium rod and the solid substrate in the regular hexagonal lattice. The regular hexagonal lattice is distributed with multiple layers from the inside to the outside. The center spacing of any two adjacent points is equal, the fiber core is located at the center of the regular hexagonal lattice, and a plurality of germanium rods are arranged in a sparse structure on each layer of the regular hexagonal lattice, and a solid substrate is filled between the germanium rods. . When the propagation constant is constant, by adjusting the diameter and refractive index of the germanium rod, when the all-solid-state microstructure fiber transmits high-power fiber laser, the high-power laser quasi-single-mode long-distance transmission can be realized and stimulated Raman scattering can be suppressed.

Description

technical field [0001] The invention mainly relates to the technical field of laser fibers, in particular to a method for suppressing stimulated Raman scattering, a high-power fiber laser and an all-solid-state microstructure fiber. Background technique [0002] High-average power lasers have been widely used in various fields such as metal cutting, material cladding, laser welding, and laser ignition due to their natural advantages such as energy concentration, flexible transformation, and small heat-affected zone. In recent years, thanks to the development of high-brightness pump sources, key optical components, laser materials, pump coupling, beam synthesis and other technologies, various types of lasers such as high-power fiber lasers, gas lasers, solid-state lasers, and semiconductor lasers Remarkable progress has been made in power improvement. Taking high-power fiber laser (HPFL) as an example, kilowatt-level fiber oscillator and amplifier technologies at home and ab...

AI Technical Summary

Problems solved by technology

However, the use of LMA fiber will inevitably cause multimode operation of the fiber, resulting in a decrease in output beam quality

In order to ensure the single-mode operation characteristics of the fiber as much as possible, it is usually required that its numerical aperture (NA) decreases with the increase of the core size, and too small NA will cause the fiber mode field area to be more sensitive to bending. , which is not conducive to its practical application

At the same time, the emergence of some microstructured fibers such as photonic crystal fibers, leaky channel fibers, multi-core fibers, and hollow-core fibers can make the fibers have the characteristics of large mode area, low NA, and constant single-mode operation. The cost of optical fiber preparation is high, the transmission loss and bending sensitivity are large, and it is generally not suitable for flexible transmission in industrial applications

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