957 research outputs found
Transport of quantum noise through random media
We present an experimental study of the propagation of quantum noise in a
multiple scattering random medium. Both static and dynamic scattering
measurements are performed: the total transmission of noise is related to the
mean free path for scattering, while the noise frequency correlation function
determines the diffusion constant. The quantum noise observables are found to
scale markedly differently with scattering parameters compared to classical
noise observables. The measurements are explained with a full quantum model of
multiple scattering
Scattering Lens Resolves sub-100 nm Structures with Visible Light
The smallest structures that conventional lenses are able to optically
resolve are of the order of 200 nm. We introduce a new type of lens that
exploits multiple scattering of light to generate a scanning nano-sized optical
focus. With an experimental realization of this lens in gallium phosphide we
have succeeded to image gold nanoparticles at 97 nm optical resolution. Our
work is the first lens that provides a resolution in the nanometer regime at
visible wavelengths.Comment: 4 pages, 3 figure
Control of light transmission through opaque scattering media in space and time
We report the first experimental demonstration of combined spatial and
temporal control of light trajectories through opaque media. This control is
achieved by solely manipulating spatial degrees of freedom of the incident
wavefront. As an application, we demonstrate that the present approach is
capable to form bandwidth-limited ultrashort pulses from the otherwise randomly
transmitted light with a controllable interaction time of the pulses with the
medium. Our approach provides a new tool for fundamental studies of light
propagation in complex media and has potential for applications for coherent
control, sensing and imaging in nano- and biophotonics
Процес «Спілки Визволення України» та зростання селянського опору в умовах суцільної колективізації
Мета даної роботи полягає у з’ясуванні механізму використання матеріалів
процесу «СВУ» на території сучасної Чернігівщини, пропагандистських цілях та
реакції на нього з боку як населення, лояльного до влади, так і селян, які вперто
чинили опір політиці колективізації
Social Obstetrics: Addressing inequalities in perinatal healthcare
Research with the aim to investigate the effectiveness of preventive strategies. These strategies were implemented during different phases in reproductive healthcare, to reduce adverse perinatal health outcomes and low empowerment particularly among women with a low socioeconomic status and their offsprin
Inhibited spontaneous emission of quantum dots observed in a 3D photonic band gap
We present time-resolved emission experiments of semiconductor quantum dots
in silicon 3D inverse-woodpile photonic band gap crystals. A systematic study
is made of crystals with a range of pore radii to tune the band gap relative to
the emission frequency. The decay rates averaged over all dipole orientations
are inhibited by a factor of 10 in the photonic band gap and enhanced up to 2?
outside the gap, in agreement with theory. We discuss the effects of spatial
inhomogeneity, nonradiative decay, and transition dipole orientations on the
observed inhibition in the band gap.Comment: 5 figures, update author lis
Determination of the diffusion constant using phase-sensitive measurements
We apply a pulsed-light interferometer to measure both the intensity and the
phase of light that is transmitted through a strongly scattering disordered
material. From a single set of measurements we obtain the time-resolved
intensity, frequency correlations and statistical phase information
simultaneously. We compare several independent techniques of measuring the
diffusion constant for diffuse propagation of light. By comparing these
independent measurements, we obtain experimental proof of the consistency of
the diffusion model and corroborate phase statistics theory.Comment: 9 pages, 8 figures, submitted to Phys. Rev.
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