System for inhibiting unstable thermotropic mode in ytterbium-doped optical fiber amplifier with high brightness and narrow linewidth

Abstract

The invention provides a system for inhibiting an unstable thermotropic mode in a ytterbium-doped optical fiber amplifier with high brightness and narrow linewidth. The system comprises a narrow-linewidth optical fiber laser seed source of which the center wavelength is lambda 1, an optical fiber laser of which the center wavelength is lambda 2, an all-optical fiber high-power wavelength divisionmultiplexer, a ytterbium-doped main amplifier, an optical fiber end cap, a collimator, a dichroscope, a power receiver I, a high reflectivity mirror, a power receiver II, a beam splitter, a photoelectric signal acquisition and display module and a light beam quality monitoring module. A beam of short-waveband laser of which the center wavelength is lambda 2 and a beam of narrow-linewidth and long-wavelength laser of which the center wavelength is lambda 1 are simultaneously injected in the narrow-linewidth ytterbium-doped optical fiber amplifier, wherein the lambda 2 is less than the lambda 1.By forming gain competition in a gain optical fiber, effective inhibition of the unstable effect of the thermotropic mode and effective output of single-wavelength and narrow-linewidth laser are realized.

Description

technical field [0001] The invention belongs to the field of strong laser technology, in particular to a system for suppressing thermally induced mode instability in a high-brightness narrow-linewidth ytterbium-doped fiber amplifier. Background technique [0002] High-brightness narrow-linewidth fiber laser has a wide range of application requirements in many application fields such as coherent synthesis, spectral synthesis, nonlinear frequency conversion, earth science, atomic and molecular physics, etc. However, as the power continues to increase, the mode will be suddenly distorted due to the existence of heat in the narrow linewidth fiber amplifier, that is, thermally induced mode instability. Since the phenomenon of thermally induced mode instability was first reported in 2010, as an important factor limiting the further brightness improvement of current fiber lasers, it has attracted widespread attention from many units at home and abroad. [0003] The research result...

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Problems solved by technology

[0006] However, despite the various suppression methods mentioned above, the thermally induced mode instability effect is still one of the key factors limiting the current high-brightness narrow-linewidth fiber amplifiers.

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