Spectrum regulating and controlling device for mid-infrared pulse lasers

Abstract

The invention discloses a spectrum regulating and controlling device for mid-infrared pulse lasers. In the spectrum regulating and controlling device, near-infrared pulse lasers emitted by a near-infrared pulse laser device and mid-infrared pulse lasers jointly enter an aperiodicity poled crystal through an optical coupling mirror, and are subjected to nonlinear frequency conversion, the near-infrared pulse lasers serve as pump light, different spectrum components of the mid-infrared pulse lasers are subjected to differentiation amplification so that spectrum regulating and controlling can be achieved. According to the spectrum regulating and controlling device for the mid-infrared pulse lasers, the I-type quasi-phase matching technology is adopted, the working temperature of the aperiodicity poled crystal is adjusted, and group velocity mismatching between the near-infrared pump light and mid-infrared signal light in the crystal is eliminated. In this way, the spectrum regulating and controlling device is suitable for femtosecond-magnitude-order mid-infrared ultra-short pulse lasers, and does not need to be chirped and broadened, spectrum shaping can be directly carried out through the near-infrared pulse lasers, and the complex degree of the spectrum regulating and controlling device based on nonlinear frequency conversion is greatly simplified.

Description

technical field [0001] The invention relates to the field of laser technology, in particular to a spectrum control device for mid-infrared pulsed laser. Background technique [0002] Mid-infrared pulsed lasers are used in many different fields, from basic research in strong-field physics to medical and industrial applications. However, due to the lack of suitable laser gain media and effective detection methods, commercialized femtosecond lasers are still dominated by titanium sapphire (Ti:sapphire) solid-state lasers and erbium-doped (Er) fiber lasers, and the laser wavelength is generally less than 2 μm. [0003] Based on existing pulsed lasers, through nonlinear frequency conversion, pulsed lasers of any wavelength can be obtained, such as the mid-infrared band (3-5 μm), which is difficult to generate directly. After years of development, quasi-phase matching (QPM) has become a mature technology for phase matching for nonlinear frequency conversion. By periodically chan...

AI Technical Summary

Problems solved by technology

Group Velocity Mismatch Causes Laser Pulse Timing Desynchronization

Among them, the walk-off between the pump light and the signal light will cause the signal light to be unable to continuously amplify, resulting in the inability of the non-periodically polarized crystal to complete the originally set goals, such as adjusting the output spectrum

In order to reduce the influence of time walk-off, in the past, non-periodically polarized crystals were mainly used for chirped pulsed lasers, or only very short non-periodically polarized crystals could be used

This greatly increases the complexity of nonlinear frequency conversion systems and creates an insurmountable barrier to their potential applications

Especially in the mid-infrared band of 3-5 μm, due to the lack of effective detection methods, pulse stretching and compression of ultrashort pulse lasers in this spectral region is still a difficult engineering task

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