| 1. |
- Kaltenecker, K. J., et al.
(author)
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Plasmonic Resonances Affecting Terahertz Generation in Laser-Induced Gas-Plasmas
- 2018
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In: International Conference on Infrared, Millimeter, and Terahertz Waves, IRMMW-THz. - : Book Series: International Conference on Infrared Millimeter and Terahertz Waves. - 2162-2027 .- 2162-2035. ; 2018-September
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Conference paper (peer-reviewed)abstract
- We demonstrate that plasmonic resonances can be used to broaden the terahertz emission spectrum from two-color laser-driven gas-plasmas. This effect can be controlled by changing the polarization properties of elliptically shaped driving laser-pulses.
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| 2. |
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| 3. |
- Martínez, P. González De Alaiza, et al.
(author)
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Modeling the time-dependent electron dynamics in dielectric materials induced by two-color femtosecond laser pulses: Applications to material modifications
- 2021
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In: Physical Review A. - 2469-9934 .- 2469-9926. ; 103:3
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Journal article (peer-reviewed)abstract
- Controlling the electron dynamics during laser-matter interactions is a key factor to control the energy deposition and subsequent material modifications induced by femtosecond laser pulses. One way to achieve this goal is to use two-color femtosecond laser pulses. In this paper, the electron dynamics in dielectric materials induced by two-color femtosecond laser pulses is studied by solving dedicated optical Bloch equations. This model includes photo- and impact ionization, the laser heating of conduction electrons, their recombination to the valence band, and their collisions with phonons. The influence of photon energies, laser intensities, and pulse-to-pulse delay is analyzed. Depending on the interaction process, colors cooperate to excite electrons or drive them independently. For the given laser parameters, an optimal pulse-to-pulse delay is found which enhances significantly the energy deposition into the material, in agreement with experimental observations.
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| 4. |
- Smetanina, E., et al.
(author)
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Modeling femtosecond laser-induced electron dynamics in dielectrics by means of optical bloch equations
- 2019
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In: 2019 Conference on Lasers and Electro-Optics Europe and European Quantum Electronics Conference, CLEO/Europe-EQEC 2019. - 9781557528209
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Conference paper (peer-reviewed)abstract
- Modern laser technologies provide high-intensity single- or few-cycle laser pulses which open new doors to study laser-matter interaction processes. To predict new routes towards their active control, advanced theoretical and numerical models are required. When approaching the highly non-linear interaction regimes close to the material damage threshold, the traditional perturbation expansion of the polarization response is not valid anymore and a quantum-mechanical modeling is essential [1-4]. A good candidate to model the electron dynamics within this framework is the Optical Bloch Equations (OBEs) approach, which provides all-order material response within a single self-consistent description. We develop a new OBEs-based model of laser matter-interaction including field-induced ionization, both linear and nonlinear polarization responses leading to high harmonics, impact ionization and various relaxation processes taking place in dielectric materials. Here, we apply our model to describe the electron dynamics induced by an intense femtosecond laser pulse in a dielectric.
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| 5. |
- Smetanina, E., et al.
(author)
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Optical Bloch modeling of femtosecond-laser-induced electron dynamics in dielectrics
- 2020
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In: Physical Review E - Statistical, Nonlinear, and Soft Matter Physics. - 2470-0053 .- 2470-0045. ; 101:6
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Journal article (peer-reviewed)abstract
- A model based on optical Bloch equations is developed to describe the interaction of femtosecond laser pulses with dielectric solids, accounting for optical-cycle-resolved electron dynamics. It includes the main physical processes at play: photoionization, impact ionization, direct and collisional laser heating, and recombination. By using an electron band structure, this approach also accounts for material optical properties as nonlinear polarization response. Various studies are performed, shedding light on the contribution of various processes to the full electron dynamics depending on laser intensity and wavelength. In particular, the standard influence of the impact ionization process is retrieved.
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| 6. |
- Thiele, Illia, 1989, et al.
(author)
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Terahertz emission from laser-driven gas plasmas: A plasmonic point of view
- 2018
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In: Optica. - 2334-2536. ; 5:12, s. 1617-1622
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Journal article (peer-reviewed)abstract
- We disclose an unanticipated link between plasmonics and nonlinear frequency down-conversion in laser-induced gas-plasmas. For two-color femtosecond pump pulses, a plasmonic resonance is shown to broaden the terahertz emission spectra significantly. We identify the resonance as a leaky mode, which contributes to the emission spectra whenever electrons are excited along a direction where the plasma size is smaller than the plasma wavelength. As a direct consequence, such resonances can be controlled by changing the polarization properties of elliptically shaped driving laser pulses. Both experimental results and 3D Maxwell consistent simulations confirm that a significant terahertz pulse shortening and spectral broadening can be achieved by exploiting the transverse driving laser beam shape as an additional degree of freedom.
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