Narrow linewidth fiber laser generating device and method based on distributed feedback

Abstract

The invention belongs to the field of fiber laser, and particularly relates to a narrow linewidth fiber laser generating device and method based on distributed feedback. The laser generating device comprises a first semiconductor pumping laser source, a first wavelength division multiplexer, an active phase shift grating, an optical circulator, a second semiconductor pumping laser source, a second wavelength division multiplexer, a doped optical fiber, a filter, a beam splitter and an optical isolator. The first wavelength division multiplexer, the active phase shift grating, the second wavelength division multiplexer, the doped optical fiber, the filter and the beam splitter jointly form an annular cavity structure through the optical circulator for injection. In the annular cavity, the signal light continuously and circularly passes through the doped optical fiber, and once amplification can be realized by stimulated radiation when the signal light passes through the doped optical fiber once, so that the output power is improved in the circular reciprocating process of the laser in the annular cavity.

Description

technical field [0001] The invention belongs to the field of fiber laser, and in particular relates to a device and method for generating narrow-linewidth fiber laser based on distributed feedback. Background technique [0002] Narrow-linewidth fiber lasers use wavelength selectors (such as F-P standards, tunable filters, or Bragg gratings, etc.) to limit the number of longitudinal modes that start to oscillate in the gain spectrum, and only allow a few modes that meet specific conditions to oscillate. Lasers have the advantages of low noise and narrow linewidth, and are widely used in optical communication, optical fiber sensing, remote sensing, spectroscopy and other fields. Narrow-linewidth fiber lasers can be used to generate narrow-linewidth lasers. Common narrow-linewidth laser generation methods include DBR, DFB, and circular cavity plus FBG structures. There are related mature products at home and abroad. For example, if a ring cavity structure is adopted, a polariz...

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Problems solved by technology

For example, if a ring cavity structure is adopted, a polarization-dependent isolator is used to polarize and select a polarization mode inside the cavity, and a grating is used to select a frequency outside the cavity. , although a bandwidth output of about 6pm can be obtained at an output power of 30mW, if the output power is required to increase to 70mW when the linewidth remains unchanged, it needs to be amplified, and the amplification will inevitably lead to widening of the linewidth, which limits its practical application

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