Device and method for realizing multi-wavelength mode-locked bright and dark pulses

Abstract

The invention provides a device and a method for realizing multi-wavelength mode-locked bright and dark pulses, and belongs to the field of laser technology and nonlinear optics. The device comprises an NALM ring, a one-way ring and a four-port coupler, the NALM ring comprises a laser pumping source input end, a beam combiner, a gain optical fiber, a first polarization controller and a single-mode optical fiber as an annular main body of the NALM ring; the one-way ring comprises a second polarization controller, an isolator and a three-port coupler which are annular main bodies of the one-way ring; the four-port coupler connects the NALM ring and the one-way ring. The device utilizes an NALM structure as an equivalent saturable absorber to realize mode locking, can output multi-wavelength mode locking bright and dark pulses, and has the advantages of low pumping power, stable mode locking, simple structure and stable and reliable system mode locking. The method can be used in the field of secret communication systems, and is of great significance to research on pulse nonlinear dynamics of fiber lasers.

Description

technical field [0001] The present invention relates to the field of laser technology. Specifically, it relates to a device and method for realizing multi-wavelength mode-locked bright and dark pulses, which is of great significance to the study of nonlinear dynamics of fiber lasers. Background technique [0002] So far, there have been many reports on mode-locked fiber lasers. By managing the parameters of the fiber resonator, conventional solitons, dissipative solitons, dissipative soliton resonances, and noise-like pulses are experimentally observed in passively mode-locked fiber lasers. However, the above pulses are all bright pulses. In addition, there is a dark pulse. Compared with bright pulses, dark pulses have the advantages of more stability and lower transmission loss, and have broad application prospects in communication and precision measurement. In addition to bright and dark pulses, bright-bright, dark-dark, bright-dark or dark-bright pulses have been theo...

AI Technical Summary

Problems solved by technology

However, real saturable absorbers have the disadvantage of low damage threshold, and it is difficult to withstand higher pulse energy; at the same time, the spectra of bright and dark pulses generated by existing fiber lasers are mostly typical single-peak wide spectra and double-peak wide spectra. And the time interval between bright and dark pulses is not adjustable

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