Multi-wavelength synchronous output fiber laser based on nonlinear polarization rotation mode locking

Abstract

The invention relates to a multi-wavelength synchronous output fiber laser based on nonlinear polarization rotation mode locking, which comprises a semiconductor laser, a wavelength division multiplexer, a gain fiber, a first collimating mirror, a first half wave plate, a first quarter wave plate, a first polarization beam splitter, a Faraday isolator, a glaring grating, and a silver mirror. According to the first half wave plate, a nonlinear polarization rotation technology is adopted for mode locking, a saturable absorber which is likely to be damaged can be prevented from being used, and the stability of the laser is enhanced. According to the same laser gain fiber and the nonlinear polarization mode locking device, the distance between two wavelengths under mutual cross phase modulation effects in the laser cavity is increased, and thus, a cavity length misadjustment range for two laser cavities in the case of synchronous mode locking can be increased. Through changing the angle of a beam-splitting grating, the output wavelength of the laser can be tuned, the gap between the two wavelengths can be changed through changing the position of the collimator in the spectral space, and through changing the position of the collimator away from the beam-splitting grating, the pulse spectral width and the pulse width of laser output pulses can be changed.

Description

technical field [0001] The patent of the present invention relates to a fiber laser, in particular to a passive mode-locked fiber laser structure with passive laser pulse synchronization, variable pulse width, tunable pulse wavelength, dual wavelength, and ultrashort optical pulse output, and each wavelength of the laser can be freely converted. Background technique [0002] Fiber lasers that can switch adjacent wavelengths and synchronize dual-wavelength mode-locked laser output can be used in many scientific and technological fields, including pump-probe ultrafast laser spectroscopy, dual-comb spectroscopy, optical sensing and measurement, optical communication etc. At present, there are mainly two methods of active mode-locking technology and passive mode-locking technology to realize fiber laser with dual-wavelength mode-locked output. Among them, the active mode-locking technology can provide high repetition rate, stable mode-locked laser pulse output, but the cost of...

AI Technical Summary

Problems solved by technology

However, dual-wavelength mode-locked lasers based on nonlinear polarization rotation technology are generally obtained by comb filters caused by intracavity birefringence to filter the intracavity laser gain, so the interval between the two wavelengths cannot be tuned in a wide range. And can't get synchronous dual wavelength pulse output

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