Mamyshev type laser oscillator with nonlinear loop filtering

Abstract

The present invention provides a Mamyshev type laser oscillator with nonlinear loop filtering. The Mamyshev type laser oscillator comprises a first nonlinear optical loop lens comprising a first coupler, a first optical amplifier, a first filter and a first phase shifter, a second nonlinear optical loop lens comprising a second coupler, a second optical amplifier, a second filter and a second phase shifter, and a broadening amplifier comprising a third optical amplifier and a fourth optical amplifier, wherein the central wavelength of the second filter is different from that of the first filter, an input end of the third optical amplifier is connected to an output port of the first nonlinear optical loop lens, an output end of the third optical amplifier is connected to an input port of the second nonlinear optical loop lens, an input end of the fourth optical amplifier is connected to an output port of the second nonlinear optical loop lens, and an output end of the fourth optical amplifier is connected to an input port of the first nonlinear optical loop lens. Pulse laser is continuously amplified, broadened, narrowed, and reshaped in the Mamyshev type laser oscillator until a stable pulse sequence is formed, and so the self-starting performance of the Mamyshev type laser oscillator is good.

Description

technical field [0001] The invention relates to the field of laser oscillators, in particular to a Mamyshev type laser oscillator with nonlinear loop filtering. Background technique [0002] Compared with traditional solid-state lasers, ultrafast fiber lasers have the advantages of high energy conversion efficiency, easy construction, convenient integration, beam quality close to the diffraction limit, low cost, and convenient maintenance. Laser oscillators are used to generate ultra-short pulse laser sources on the order of picoseconds or even femtoseconds, and are the core components of high-power fiber lasers. The Mamyshev-type laser oscillator based on pulse re-amplification and pulse reshaping can further increase the pulse energy of the fiber laser to the order of hundreds of nJ. Specifically, the Mamyshev-type laser oscillator relies on the spectral broadening effect caused by self-phase modulation in the fiber and The spectral selection effect of the filter element ...

AI Technical Summary

Problems solved by technology

[0003] However, the existing Mamyshev-type laser oscillators are usually difficult to achieve self-starting, which requires additional seed pulses or external electrical modulation pulses during start-up

In order to make the Mamyshev laser oscillator self-starting, it is necessary to introduce a saturable absorption mechanism in the Mamyshev laser oscillator to assist in the generation of ultrashort pulse sequences. At present, nonlinear optical loop mirrors are usually used in all-fiber laser oscillators to generate ultrashort Pulse, for example, patent document CN 103311780 A discloses a kind of laser with nonlinear optical loop mirror (the laser has a laser resonator, which is equivalent to a laser oscillator), the laser realizes self-starting by adopting nonlinear optical loop mirror, but , it is difficult for the laser to generate a stable ultrashort pulse laser sequence through a single nonlinear optical loop mirror, which makes the self-starting performance of the laser poor and low

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