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Invitation to a talk by Valentina Shumakova

09.01.2020

Self-compression and nonlinear propagation of multi-mJ fs mid-IR pulses

Valentina Shumakova

Photonics Institute Vienna University of Technology, Gusshausstraße 27-38, 1040 Vienna

 

Friday, January 10th , 2020, 10:15

Seminarroom 3510, 5th floor Boltzmanngasse 5, 1090 Vienna

Fakultät für Physik

Fakultätszentrum für Nanostrukturforschung

Self-compression and nonlinear propagation of multi-mJ fs

mid-IR pulses

Hosted by: Oliver Heckl

The physics of the strong-field applications, such as filamentation, laser-driven particle acceleration, generation of high harmonics and intense THz radiation, requires driver laser pulses that are both energetic and extremely short. Moreover, since these applications benefit from extending the oscillation period of the driving electromagnetic field, a longer carrier wavelength is often desirable. Due to the absence of broadband laser gain materials, the common approach for the generation of multi-mJ femtosecond mid-infrared pulses is optical parametric (chirped pulse) amplification (OP(CP)A). However, the peak power of the pulses from OP(CP)A systems is limited by the maximum energy of pump lasers and restricted by phase-matching bandwidth, as well as the nonlinear phase accumulation in crystals during the amplification. Therefore, external spectral broadening and pulse compression, leading to a corresponding peak power increase, are required. Furthermore, a delivery of the generated few- cycle pulses on the remote target is often complicated due to the dispersion, random fluctuations of the material refractive index and nonlinear self-actions.

This work explores the methods of generation of sub-TW multi-mJ fs mid-IR pulses and investigates their nonlinear propagation in transparent dielectric media. We validate, that high peak-power few-cycle pulses can be generated through a nonlinear soliton-like self- compression in mm-long bulk solids and in the ambient air. Furthermore, we show how spectral, temporal, spatial and energetic characteristics of the mid-IR pulse, depend on multiple parameters, such as environmental conditions, focusing strength and temporal chirp of the pulses.