Narrow-linewidth fiber laser spectrum broadening device based on periodic noise phase modulation

Abstract

The invention relates to a narrow-linewidth optical fiber laser spectrum broadening device based on periodic noise phase modulation. The narrow-linewidth optical fiber laser spectrum broadening devicecomprises a single-frequency seed laser device, a phase modulator, a programmable signal generator, a radio frequency amplifier, an optical fiber pre-amplifier, an optical fiber coupler, an optical fiber amplifier, a first optical power meter, a second optical power meter and a signal and data processing system. According to the invention, the single-frequency seed laser is subjected to phase modulation broadening based on the periodic noise signal, so that the modulated spectral fine structure characteristics can be controlled by optimizing the waveform and/or period of the noise signal; andfor different optical fiber amplifiers, by optimizing the waveform and/or period of a noise signal, the SBS threshold value can be effectively improved under the condition that the line width is as small as possible while random self-pulses can be prevented from being generated.

Description

technical field [0001] The invention relates to the technical field of laser spectrum broadening, in particular to a narrow-linewidth fiber laser spectrum broadening device based on periodic noise phase modulation. Background technique [0002] Limited by physical factors such as nonlinearity, mode instability, and thermal lens effect, the output power of a single fiber laser is limited. Using multiple fiber lasers for spectral synthesis or coherent synthesis can greatly increase laser power while maintaining good beam quality. However, both spectral synthesis and coherent synthesis require that the linewidth of the fiber laser sub-beams participating in the synthesis be controlled within a certain range, that is, the sub-beams participating in the synthesis are required to be narrow-linewidth fiber lasers. To achieve high-power narrow-linewidth fiber laser, a narrow-linewidth seed source power amplification structure is generally used. At present, commonly used narrow-line...

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Problems solved by technology

[0006] The object of the present invention is to provide a narrow-linewidth fiber laser spectrum broadening device based on periodic noise phase modulation, which can control the modulated spectral linewidth through modulation frequency and modulation depth, and can optimize the waveform and/or period of the noise sign

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