2-5 [mu] m wave band cascade soft glass optical fiber intermediate infrared broadband spectrum laser

Abstract

The invention provides a 2-5 [mu] m wave band cascade soft glass optical fiber mid-infrared broadband spectrum laser, which obtains 2 [mu] m wave band seed laser by adopting a passive mode locking mode, amplifies laser power through a multi-stage amplifier, performs pulse broadening by utilizing an optical fiber pulse broadening device, and obtains a wide spectrum of 2 [mu] m wave band seed laser by managing the nonlinear effect of each stage of amplification and the thermal effect of a gain optical fiber. The light conversion efficiency can be improved, the obtained pump light source with the waveband of 2 microns further pumps the cascaded soft glass optical fibers, heat dissipation treatment is carried out on the melting point and the soft glass optical fibers through refrigerated nitrogen, heat accumulation at the melting point is effectively relieved, and the average power output of tens of watts can be obtained. Based on an all-fiber structure, the fiber laser has the advantages of being compact in structure, high in integration degree, good in stability, high in conversion efficiency and the like, is not sensitive to interference factors such as vibration in a working environment, greatly improves the stability and reliability of operation of the laser, is suitable for industrial mass production, and is more beneficial to construction of a large laser system.

Description

technical field [0001] The invention belongs to the field of laser technology, and in particular relates to a mid-infrared wide-spectrum laser with 2-5 μm band cascaded soft glass optical fibers. Background technique [0002] Mid-infrared ultrashort pulse fiber laser has the advantages of high light conversion efficiency, good beam quality, simple and compact structure, etc. It is known as a new generation of high-performance industrial lasers, medical lasers and military lasers. In particular, the 2-5μm mid-infrared band is an atmospheric window with high transmittance, and it is also a common response spectrum band of various detectors in photoelectric countermeasures, which has a major strategic demand in the field of national defense security. In order to generate mid-infrared SCs, nonlinear optical fibers with low transmission loss in the mid-infrared region, such as soft glass fibers composed of tellurates, sulfides, and fluorides, are usually obtained by pumping nonli...

AI Technical Summary

Problems solved by technology

However, the average power, spectral width, and spectral flatness of mid-infrared ultrashort-pulse fiber lasers are still limited by nonlinear soft glass fiber transmission loss and splicing efficiency.

At the same time, due to the large difference in glass softening temperature between mid-infrared soft glass fiber and ordinary quartz glass fiber (for example, the glass softening temperature difference between ZBLAN fiber and quartz fiber is nearly 1000 ° C), resulting in a large fusion loss between the two, which is very important for realizing high-power all-fiber Broad-spectrum laser output in the mid-infrared band poses challenges

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