A method for generating high-power mid-infrared ultrafast pulsed lasers

Abstract

The invention relates to a method for generating high-power intermediate-infrared ultrafast pulse laser. According to the method, first pumping light with a central wavelength being 1,020-1,040 nanometers is sent to a non-linear crystal for non-linear spontaneous parameter conversion after amplification, so that intermediate-infrared pulse seed light of 2.85-3.1 micrometers and following pulse pumping light of 1,580-,1600 nanometers are obtained; the seed light and the pumping light are coupled to one end of a Er<3+> fluoride-doped gain fiber, second pumping light with a central wavelength being 970-980 nanometers is input to the other end of the Er<3+> fluoride-doped gain fiber, the energy level and the ground state under intermediate-infrared transition are right corresponding to a radiation wavelength being about 1.6 micrometers, the accumulated particles by the energy lever under the intermediate-infrared laser can be rapidly fallen into the ground state by the introduction of thepumping light, so that the lifetime of the energy lever of the laser is reduced, the intermediate-infrared laser amplification efficiency can be remarkably improved, the damage of thermal effect to afluoride soft fiber is reduced, and stable high-power intermediate-infrared ultrashort pulse output can be obtained.

Description

technical field [0001] The invention relates to the field of laser technology, in particular to a method for generating high-power mid-infrared ultrafast pulse laser. Background technique [0002] The mid-infrared band not only covers multiple transparent windows of the earth's atmosphere (such as K, L, M, and N bands), but also covers the vibration-rotational absorption lines of many molecules (also known as the "molecular fingerprint" spectral region). Therefore, mid-infrared laser sources have important applications in many fields of science and technology, such as molecular spectrum analysis, optical frequency metrology, free space communication, infrared laser surgery, infrared ranging and countermeasures, etc. In particular, since the 3μm band corresponds to the resonant absorption peak of the symmetrical stretching vibration of the O-H chemical bond in liquid water, the mid-infrared laser in this band has a strong absorption in water, and can be used for the incision ...

AI Technical Summary

Problems solved by technology

Although this technology can alleviate the bottleneck of particle population concentration at the lower energy level of the laser, the transition processes involved in the excited state absorption, energy transfer up-conversion, etc. will increase the pumping threshold power of the laser, making the laser efficiency low, The output power is small, which greatly limits the practical application of mid-infrared lasers

Another commonly used method is to incorporate an appropriate amount of Pr 3+ Rare earth elements such as rare earth elements are used as deactivated ions to achieve the purpose of pumping the lower energy level particles of the laser through ion resonance energy transfer, thereby effectively reducing the life of the energy level, lowering the laser threshold, and finally improving the laser efficiency and output power. Although this technology is in a certain To a certain extent, the laser output power and efficiency have been improved, but there is still a lot of room for improvement

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