Method and device for generating ultrashort pulses based on single- and double-mode fiber lasers

Abstract

The application discloses a kind of based on single-double mode optical fiber laser's ultra-short pulse generation method and device, method includes: pump light enters erbium-doped optical fiber by double-mode wavelength division multiplexer, excitation erbium ion to upper level and form particle number inversion, produce stimulated emission, amplify laser signal;Pass through double-mode optical fiber coupler, a small amount of laser output to outside cavity and measure, remaining laser continues to oscillate in cavity;Remaining laser passes through polarization controller and adjusts the polarization state in resonant cavity, to ensure that laser is stably transmitted in cavity, utilize carbon nanotube saturable absorber to realize the mode locking of laser, ensure that stable ultra-short pulse is generated;Laser passes through double-mode isolator and ensures that optical pulse is unidirectional operation in resonant cavity, re-enters double-mode wavelength division multiplexer and forms circulation;After periodic mode coupling, finally form stable mode-locked pulse.The application is suitable for few-mode fiber mode-locked laser, with simple structure, easy to construct and maintain, with very high stability and reliability.

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