Fig. 1. (a)–(c) Three-band structure for a non-centrosymmetric direct-gap semiconductor: GaAs (111) inspired (a) dipole coupling strength, (b) energies, and (c) their gradients. (d) High-harmonic spectra generated by an SBE model for E=108  V/m, θ=100  fs FWHM pulse duration and long-, mid-, and near-infrared wavelengths λ.

Fig. 2. Spatiotemporal evolution of (a), (c) electric fields, (b), (d) averaged carrier densities inside the slab of (a), (b) 12 μm and (c), (d) 24 μm thicknesses. Laser irradiation parameters are E=108   V/m, θ=100  fs FWHM pulse duration, and λ=10.6  μm. k→ indicates the propagation direction of laser pulse. Solid lines in (a), (c) show the position of the slab.

Fig. 3. (a) Transmission spectra (solid lines) upon propagation on distances of compared to the emission spectra from point SBE model (dashed line). Comparison of transmission (red) and reflection (blue) spectra for slabs of (b) 12 μm and (c) 48 μm thickness; temporal evolution of the corresponding electric fields for (d) 12 μm and (e) 48 μm slabs. Incident pulses are marked by yellow boxes. Laser irradiation parameters are E=108   V/m, θ=100  fs FWHM pulse duration, and λ=10.6  μm.

Fig. 4. (a) Extinction cross section for GaAs nanoparticles of different radii. Magnetic dipole (MD), electric dipole (ED), and magnetic qudrupole (MQ) resonances are indicated. (b) 1D conduction band densities Ne at the distance from the nanoparticle center zero along propagation direction z. (c)–(f) Averaged intensity distributions in the propagation plane (2D) for GaAs nanoparticles excited by E=108   V/m incident field at fundamental wavelength λ=1.5  μm. Corresponding radii R are indicated above each sub-figure. Laser polarization E→ and propagation direction k→ are shown.

Fig. 5. (a) Transmission and (b) reflection spectra for GaAs nanoparticles of different radii. Laser irradiation parameters are E=108   V/m, θ=100  fs FWHM pulse duration, and λ=1.5  μm.