Femtosecond pulse compressor based on two segments of quasi-phase-matching crystals

Abstract

The invention aims at providing a femtosecond pulse compressor based on two segments of quasi-phase-matching crystals. The compressor comprises a first segment of crystal, a second segment of crystal and a Pi / 2 phase-adjusting crystal. The length of the first segment of crystal is shorter than that of the second segment of crystal, the Pi / 2 phase-adjusting crystal is arranged between the first segment of crystal and the second segment of crystal, and the length of the Pi / 2 phase-adjusting crystal is half of the domain period of the first segment of crystal. The invention can realize femtosecond pulse compression without obvious base, in addition, energy transfer tends to be stable, and input intensity has lower threshold property.

Description

technical field [0001] The invention belongs to the technical field of lasers, and in particular relates to a femtosecond pulse compressor based on two-stage quasi-phase matching crystals. Background technique [0002] Femtosecond laser has the characteristics of extremely short duration and very high instantaneous power, which expands the research fields of femtosecond chemistry, femtosecond biology, quantum modulation and coherent spectroscopy. [0003] Solid-state femtosecond laser technology is becoming more and more mature and has been applied to many fields. The external compression technology can obtain shorter femtosecond or sub-femtosecond pulses by compressing, shaping and regeneratively amplifying the existing laser pulse output. Existing feasible compression technologies include the following: (1) Adiabatic compression based on Dispersion Decreasing Fiber (DDF), although this technology can obtain compressed pulses without obvious bases when the input power is n...

AI Technical Summary

Problems solved by technology

Existing feasible compression technologies include the following: (1) Adiabatic compression based on Dispersion Decreasing Fiber (DDF), although this technology can obtain compressed pulses without obvious bases when the input power is not high , but the compression ratio of this technology is small, and the required DDF is longer (above tens of kilometers); (2) the compression realized by the combination of optical fiber and grating, although the optical pulse with micron-level wavelength and femtosecond-level pulse width can be obtained Compression, but its disadvantage is that the large peak power of the pulse will destroy the fiber itself; (3) using supercontinuous white light as the signal light, using broadband non-collinear optical parametric amplification in the BBO crystal to obtain periodic pulses, And the energy of ~1uJ, but the application is very limited; (4) periodic QPM compression, the compressed pulse has an obvious base, and the oscillation is relatively large during energy transmission

[0004] The main disadvantage of the above compression method is that the energy transmission oscillation is large, causing the compressed pulse to have an obvious base, and the experimental device is complicated

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