Multi-color femtosecond laser generation device based on air-forming filaments

Abstract

The invention discloses a multi-color femtosecond laser generating device based on air filamentation. Two incident rays which participate in four-wave mixing are respectively a base laser pulse emitted from a titanium sapphire regenerating amplifier and a wide-spectrum laser pulse obtained by the filamentation of the femtosecond laser in air. The multi-color femtosecond laser generating device structurally comprises a beam splitting sheet on a main light path for dividing the incident rays into reflection rays and transmission rays, wherein the reflection rays are subjected to femtosecond filamentation in air to broaden spectrums, and are finally focused to a transparent nonlinear crystal; the transmission rays are finally focused on the nonlinear crystal; after intensity attenuation and time delay; two beams of incident rays are regulated to superpose in time and space, so that a plurality of beams of multi-color femtosecond laser can be obtained. The device disclosed by the invention has the characteristics of being convenient to regulate, compact in structure, economical and practical, adjustable in multi-color light center wavelength and strong in output power.

Description

technical field [0001] The invention relates to a femtosecond laser, in particular to a multicolor femtosecond laser generating device based on air-forming filaments. [0002] technical background [0003] Femtosecond lasers have important applications in many cutting-edge scientific experiments such as physical optics, chemical optics, and bio-optics. At present, the central wavelength tunable femtosecond laser is usually generated by using a non-collinear parametric amplifier based on the second-order nonlinear coefficient. However, the non-collinear parametric amplifier can only generate one beam of femtosecond laser at a time. If some experiments require multiple beams of central wavelength Different femtosecond lasers must use multiple non-collinear parametric amplifiers, which undoubtedly increases the experimental cost. Based on cascaded four-wave mixing, multiple femtosecond lasers with adjustable center wavelength and wide spectral bandwidth can be generated at one ...

AI Technical Summary

Problems solved by technology

In the past, some generation devices based on cascaded four-wave mixing multicolor femtosecond lasers used hollow-core fibers to expand the spectrum of the incident pump, which made the experimental devices take up more space and the adjustment of hollow-core fibers was complicated; some used non-collinear parameters Amplifiers are used to generate adjustable incident pump light, which leads to an uncompact arrangement of the experimental device and a relatively high cost of the experiment; some use gemstones to form filaments to broaden the spectrum, but the energy of the generated polychromatic light is relatively weak

In the past, the adjustment of the central wavelength of polychromatic light is usually to adjust the crossing angle or time delay of the incident light, but the operation of adjusting the crossing angle is relatively complicated, and the adjustment of the time delay makes the central wavelength of polychromatic light change, but the output power of polychromatic light is due to the incident light There will be obvious changes without good time coincidence

The above various factors limit the application of devices based on cascaded four-wave mixing polychromatic light

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