Related papers: Modeling upconversion of erbium doped microcrystal…
A very promising approach to obtain efficient upconversion of light is the use of triplet-triplet annihilation of excitations in molecular systems. In real materials, besides upconversion, many other physical processes take place -…
The upconversion process for the $Er^{3+}$ ion, when irradiated with IR photons at 980 nm, strongly depends upon the presence of the sensitizer $Yb^{3+}$ ions. There is a good correlation between the relative and absolute concentrations of…
Solar photons possessing energy less than the band-gap of a single-junction solar cell can be utilized via the up-conversion (UC) of two or more photons, resulting in the emission of a single above-bandgap photon. Due to the non-linear…
We present a theoretical study of the ultrafast electron dynamics in transition metals using ultrashort pulsed laser beams. The significant influence of the contribution of the dynamics of produced nonthermal electrons to electron…
In this work I summarize some of the recent work carried out by our group on the upconversion dynamics of Er3+-doped potassium lead halide crystals, which possess very small phonons and present very efficient blue and green upconversion.…
Efficient conversion of photons to electrical energy has a wide variety of applications including imaging, energy harvesting, and infrared detection. The coupling of electromagnetic radiation to free electron oscillations at a metal…
We propose a novel scheme of photon upconversion based on harnessing the energy of plasmonic hot carriers. Low-energy photons excite hot electrons and hot holes in a plasmonic nanoparticle, which are then injected into an adjacent…
We calculate the photoionization with excitation-to photoionization ratios for atomic helium and heliumlike ions at intermediate values of the photon energies. The final state interactions between the electrons are included in the lowest…
We propose a device for the reversible and quiet conversion of microwave photons to optical sideband photons, that can reach 100% quantum effciency. The device is based on an erbium doped crystal placed in both an optical and microwave…
Upconversion luminescence consists of the absorption of low-energies photons followed by the emission of a higher energy photon. The process has mainly been studied in lanthanides to upconvert monochromatic near-infrared excitation to…
The motion of electrons under homogeneously applied electric fields in low-dimensional systems with non-zero off-diagonal effective mass (ODEM) is studied. The equation describing the time evolution of a probability coefficient of finding…
In this work, we illustrate the recently introduced concept of the cavity Born-Oppenheimer approximation for correlated electron-nuclear-photon problems in detail. We demonstrate how an expansion in terms of conditional electronic and…
This paper describes the effects of electronic nonequilibrium in a simulation of ultrafast laser irradiation of materials. The simulation scheme based on tight-binding molecular dynamics, in which the electronic populations are traced with…
Frequency conversion process is studied in a medium of atoms with a $\Lambda$ configuration of levels, where transition between two lower states is driven by a microwave field. In this system, conversion efficiency can be very high by…
Interfacial ultrafast electron migration processes are simulated in finite cluster models of dye-sensitized solar cells within a single active electron approach. Initially, three different donor-acceptor $\pi$-conjugated dyes supported on…
The efficiency of the frequency conversion process at the heart of Raman heterodyne spectroscopy was improved by nearly four orders of magnitude by resonant enhancement of both the pump and signal optical fields. Our results using an erbium…
Purpose: A novel approach using nano technology enhanced radiation modalities is investigated. The proposed methodology uses antibodies labeled with organically inert metals with a high atomic number. Irradiation using photons with energies…
Free electrons are unique tools to probe and manipulate nanoscale optical fields with emerging applications in ultrafast spectromicroscopy and quantum metrology. However, advances in this field are hindered by the small probability…
We present an experimental characterization of the statistics of multiple photon pairs produced by spontaneous parametric down-conversion realized in a nonlinear medium pumped by high-energy ultrashort pulses from a regenerative amplifier.…
We study the dynamics of charge-transfer insulators after a photo-excitation using the three-band Emery model which is relevant for the description of cuprate superconductors. We provide a detailed derivation of the nonequilibrium extension…