Related papers: Ultrafast Energy Absorption in Silicon Controlled …
We investigate the non-linear response and energy absorption in bulk silicon irradiated by intense 12-fs near-infrared laser pulses. Depending on the laser intensity, we distinguish two regimes of non-linear absorption of the laser energy:…
We theoretically investigate the optical energy absorption of crystalline silicon subject to dual-color femtosecond laser pulses, using the time-dependent density functional theory (TDDFT). We employ the modified Becke-Johnson (mBJ)…
The development of high-intensity ultrashort laser pulses unlocks the potential of pump-probe spectroscopy in sub-femtosecond timescale. Notably, subcycle pump pulses can generate electronic states unreachable by conventional multicycle…
By combining genetic algorithm and a spatial light modulator we theoretically analyse how to improve a two-photon cascade absorption in atomic ensembles, inspecting the impact of various configurations and parameters in the optimized phase…
We investigate how the quantum control of a two-level system (TLS) coupled to photons can modify and tune the TLS's photon absorption spectrum. Tuning and controlling the emission and the absorption is of much interest e.g.\ for the…
We demonstrate and study the enhancement of intermediate-field two-photon absorption by shaped femtosecond pulses having spectral phases of antisymmetric nature. The intermediate-field regime corresponds to pulse intensities, where the…
The effect of ultrashort laser-induced morphological changes upon irradiation of silicon with double pulse sequences is investigated under conditions that lead to mass removal. The temporal delay between twelve double and equal-energy…
Coherent control of femtosecond two-photon absorption in the intermediate-field regime is analyzed in detail in the powerful frequency domain using an extended 4th-order perturbative description. The corresponding absorption is coherently…
The pronounced dependence of the nonlinear parameters of both dielectric and semiconductor materials on the wavelength, and the nonlinear interaction between the ultra-short laser pulse and the material requires precise control of the…
Nonlinear electronic excitation in laser-irradiated silicon at finite electron temperatures is numerically investigated by first-principles calculations based on the time-dependent density functional theory. In bulk silicon at finite…
We present a theoretical investigation of the yet unexplored ultrafast processes and dynamics of the produced excited carriers upon irradiation of Silicon with femtosecond pulsed lasers in the mid-infrared (mid-IR) spectral region. The…
We extend the powerful frequency-domain analysis of femtosecond two-photon absorption to the intermediate-field regime, which involves both two- and four-photon transitions. Consequently, we find a broad family of shaped pulses that enhance…
We apply the coupled dynamics of time-dependent density functional theory and Maxwell equations to the interaction of intense laser pulses with crystalline silicon. As a function of electromagnetic field intensity, we see several regions in…
Nonlinear optical phenomena in silicon such as self-focusing and multi-photon absorption are strongly dependent on the wavelength, energy and duration of the exciting pulse. Thus, a pronounced wavelength dependence of the sub-surface…
A study of damage and ablation of silicon induced by two individual femtosecond laser pulses of different wavelengths, 1030 and 515 nm, is performed to address the physical mechanisms of dual-wavelength ablation and reveal possibilities for…
The ultrafast time-dependence of the energy absorption of covalent solids upon excitation with femtosecond laser pulses is theoretically analyzed. We use a microscopic theory to describe laser induced structural changes and their influence…
We present and implement a new scheme for extended multi-channel selective femtosecond coherent control based on symmetry properties of the excitation channels. Here, an atomic non-resonant two-photon absorption channel is coherently…
The optical properties of silicon can be greatly tuned by applying strain and opening new perspectives, particularly in applications where infrared is key. In this work, we use a recent model for the indirect light absorption of silicon and…
Field enhancement of two-photon absorption from a 50-fs pulse on a silicon ridge waveguide is simulated for a varying energy downward propagating 800+/-9.42 nm wavelength plane-wave orthonormal to a waveguide in 2D FDTD using ANSYS…
The creation of well-thermalized, hot and dense plasmas is attractive for warm dense matter studies. We investigate collisionally induced energy absorption of an ultraintense and ultrashort laser pulse in a solid copper target using…