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The physics of solid-state nanostructures is governed by the fact that materials properties change drastically when spatial dimensions are reaching the deBroglie wavelength of electrons. During the last decade, completely new functionalities have been achieved by exploiting these effects. On the other side, a comparable control in the fourth dimension, time, is still missing since it demands to manipulate...
Recent studies on ultrafast dynamics of solids and nanostructures using few-cycle electromagnetic transients in the far and mid infrared spectral regions are presented. We are able to excite with phase-locked wave forms reaching peak amplitudes beyond 1 V/Å which are comparable to inner-atomic fields. At the same time, a quantum-limited sensitivity is approached in electro-optic detection. Such capabilities...
In a three-level lambda system, a destructive interference between excitation pathways at laser excitation can provide the resonant reduction of fluorescence and absorption (“dark resonance”). The dark resonances in rubidium vapor excited by a femtosecond laser or laser with frequency shifted feedback have been studied theoretically and experimentally.
We show that photon quantum correlations can be measured by two photon absorption in semiconductors. Hanbury-Brown Twiss experiments can thus be performed with genuine blackbodies with a time resolution in the femtosecond range.
Terahertz (THz) emissions of an isolated atom in an ultrashort (100 fs) laser field are simulated by solving the time-dependent Schroumldinger equation. From numerical calculations with one- and three-dimensional hydrogen atom models and a short-range shallow potential model, it can be concluded that continuum THz emissions occur more readily following transitions involving intermediate states above...
Using numerical method, the authors investigate various features of the closed four-level system in the ultrafast regime. The probe absorption changes upon the phases of the fields to exhibit EIT, dispersion-like absorption, or enhanced absorption.
By using field-free molecular alignment, we demonstrate the multi-filaments of ultrashort laser pulse with input spatial ellipticity can be suppressed to be a single core, or be controlled to various structures with modulated spectra.
Quantum information science has shown that harnessing quantum mechanical effects can dramatically improve performance for certain tasks in communication, computation and measurement. Already a number of photonic quantum circuits have been realized for quantum metrology, lithography and quantum logic gates. However, these demonstrations have relied on large-scale (bulk) optical elements bolted to large...
Using femtosecond pump probe spectroscopy with sub-20 fs resolution, we probe fundamental properties of the En exciton in (6,5) single walled carbon nanotubes, prepared by density gradient ultracentrifugation. From the initial photobleaching (PB) signal, measured faster than any relaxation process, we obtain the one- dimensional electron-hole correlation length ("exciton size") of the excitonic...
We report on experimental measurements of coincidence and single particle spectral shapes of biphoton signals when frequency entangled states are generated by SPDC crystals pumped by short pulses. It is shown evidence for biphoton coincidence spectrum narrower and single-particle one wider than the pump spectrum, with a large contrast between coincidence and singles distributions. The investigation...
We have developed the technique of two-photon joint temporal density measurements for temporal state characterization, thus facilitating two-photon generation with high temporal entanglement or nearly factorizable outputs by controlling the ultrafast pump bandwidth.
The second-order coherence properties of highly-incoherent cw sources (true blackbody and amplified spontaneous emission) are directly evidenced at femtosecond timescales by use of an interferometric autocorrelator based on a two-photon absorption in a GaAs phototube.
We use attosecond angular streaking to place an intensity-averaged upper limit of 12 attoseconds on the tunneling delay time in strong field ionization of helium. This is far shorter than most tunneling times discussed before.
This paper presents the concepts of metal nanoantennas and dielectric microresonators for solid-state quantum optics. For the microresonators, the concept is extended into the ultraviolet region and the first dielectric pillar microcavity with colloidal ZnO quantum dots is demonstrated. On the other hand, a tunable bowtie optical nanoantenna which consists of two gold nanotriangles is fabricated and...
On basis of numerical simulations we have forward a way to realize high-stable noise-proof information sequences of ultrashort pulses, whose unique properties are caused by properties of the bound structural solitons. Coding of the information in such sequences is carried out through a distribution along the soliton train of various types of bonds between neighboring solitons. For pair bound solitons...
A photonic crystal cavity with a strongly coupled quantum dot is coherently driven using short laser pulses. Depending on the driving frequency, photon blockade or photon induced tunneling is observed. These nonlinear phenomena at single photon level are used for on-chip generation of nonclassical light.
The nonresonant scattering of an electron by a muon in the field of a pulsed light wave in the frame of the Born approximation is investigated theoretically. The approximation when a pulsewidth is considerably greater than the characteristic time of the wave oscillation is considered. The analytical expressions for the amplitude and cross-section of mentioned process are derived in case of moderately...
We discuss characterization of single-photon wave packets by measuring Hong-Ou-Mandel interference with a weak coherent pulse. A complete multimode calculation is presented and effects of multiphoton terms in the coherent field as well as the impact of source and detection imperfections are discussed.
We demonstrate a new technique of efficient, time-resolved, infrared single-photon detection using non collinearly phase-matched frequency upconversion by an ultrafast pump, allowing nearly background-free sub-picosecond characterization of 1582-nm time anti-correlated entangled photons.
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