Related papers: Saturable absorption in highly excited silicon and…
We employ ultra-broadband terahertz-midinfrared probe pulses to characterize the optical response of photoinduced charge-carrier plasmas in high-resistivity silicon in a reflection geometry, over a wide range of excitation densities…
We demonstrate that absorption saturation of a mid-infrared intersubband transition can be engineered to occur at moderate light intensities of the order of 10-20 kW$.$cm$^{-2}$ and at room temperature. The structure consists of an array of…
Quantitative analysis of slow light experiments utilising coherent population oscillation (CPO) in a range of saturably absorbing media, including ruby and alexandrite, Er3+:Y2SiO5, bacteriorhodopsin, semi-conductor quantum devices and…
It is shown experimentally that the photodetachment yield of surplus electrons created by plasma-induced charging of non-conductive surfaces of dielectric materials depends on the initial surface charge density and do not correlate with the…
The interaction of intense light with matter gives rise to competing nonlinear responses that can dynamically change material properties. Prominent examples are saturable absorption (SA) and two-photon absorption (TPA), which dynamically…
Theory of optical absorption of linearly and circularly polarized light in surface and edge states in topological insulators is developed for a nonlinear in light intensity regime. The absorbance for surface states and the absorption width…
Photonic nanocavities are a key component in many applications because of their capability of trapping and storing photons and enhancing interactions of light with various functional materials and structures. The maximal number of photons…
The ultrashort pulse laser operation is crucially defined by engaging explicit modulators. Conventionally, they are laborious to incorporate into an all-fibre design or involve the design of sophisticated cavities. We exploit Thulium-doped…
In atomically thin semiconductors based on transition metal dichalcogenides, photoexcitation can be used to generate high densities of electron-hole pairs. Due to optical nonlinearities, which originate from Pauli blocking and many-body…
I theoretically investigate the response of bulk semiconductors to excitation by twisted light below the energy bandgap. To this end, I modify a well-known model of light-semiconductor interaction to account for the conservation of the…
We report on the response of graphene to high intensity mid-IR radiation and show that graphene exhibits saturable absorption and significant two-photon absorption in the spectral region from 1.55 $\mu$m to 3.50 $\mu$m (0.35 eV to 0.80 eV).…
Saturation effects affecting absorption and fluorescence spectra of an atomic vapor confined in an Extremely Thin Cell (cell thickness $L < 1 \mu m$) are investigated experimentally and theoretically. The study is performed on the $D_{2}$…
The nonlinear absorption of two-dimensional molybdenum disulfide was analyzed using the Z-scan technique. Sample size corresponding to a number of layer determines the band gap in the materials which play the key role for nonlinearity.…
We generate silicon vacancy related defects in high-quality epitaxial silicon carbide layers by means of electron irradiation. By controlling the irradiation fluence, the defect concentration is varied over several orders of magnitude. We…
Self-consistent simulations of the ultrafast electron dynamics in thin metal films are performed. A regime of nonlinear oscillations is observed, which corresponds to ballistic electrons bouncing back and forth against the film surfaces.…
We investigate the non-thermal material dynamics of strongly excited silicon during ultra-fast laser ablation. In contrast to metals, silicon shows strongly excitation-dependent interatomic bonding strengths, which gives rise to a number of…
The nonlinear absorption of laser radiation of relativistic intensities in the underdense plasma by a mechanism of stimulated bremsstrahlung of electrons on the ions/nuclei is investigated in the low frequency approximation. Coefficient of…
Polaronic effects involving stabilization of localized charge character by structural deformations and polarizations have attracted considerable investigations in soft lattice lead halide perovskites. However, the concept of polaron…
We employ a silicon dielectric waveguide to confine and concentrate terahertz pulses, and observe that the absorption saturates under strong terahertz fields. By comparing the response between lightly-doped and intrinsic silicon waveguides,…
The photo-induced desorption and oxidation of CO on Ru(0001) is simulated using ab initio molecular dynamics with electronic friction that accounts for the non-equilibrated excited electrons and phonons. Different (O,CO) coverages are…