Browse
Submit Data
Databases
API
Help

Dataset Information

0 Views

0 Connections

0 Citations

0 Reanalyses

0 Downloads

Omics score: 0

Superoscillations without sidebands: power-efficient sub-diffraction imaging with propagating waves.

ABSTRACT: A superoscillation wave is a special superposition of propagating electromagnetic (EM) waves which varies with sub-diffraction resolution inside a fixed region. This special property allows superoscillation waves to carry sub-diffraction details of an object into the far-field, and makes it an attractive candidate technology for super-resolution devices. However, the Shannon limit seemingly requires that superoscillations must exist alongside high-energy sidebands, which can impede its widespread application. In this work we show that, contrary to prior understanding, one can selectively synthesize a portion of a superoscillation wave and thereby remove its high-energy region. Moreover, we show that by removing the high-energy region of a superoscillation wave-based imaging device, one can increase its power efficiency by two orders of magnitude. We describe the concept behind this development, elucidate conditions under which this phenomenon occurs, then report fullwave simulations which demonstrate the successful, power-efficient generation of sub-wavelength focal spots from propagating waves.

SUBMITTER: Wong AM

PROVIDER: S-EPMC4326778 | biostudies-other | 2015

REPOSITORIES: biostudies-other

ACCESS DATA

Json Xml

Similar Datasets

Propagating Precipitation Waves in Disordered Media.

Project description:The study presented in this paper investigates form changes of propagating waves generated through precipitation reactions in a gel matrix that possesses an inhomogeneous microstructure. The waves demonstrate form changes from a single ring-like pattern to multiple target-like waves. Subsequently, the waves take up a spiral form and ultimately manifest themselves in the form of a turbulence pattern that intensifies with increasing fluctuations within the gel structure. An investigation into the dynamics of the precipitation waves reveals the existence of an anomalous diffusion. The effective diffusion coefficients are found to increase linearly with the quenching temperature. Further, it is revealed through the analysis of the anomalous diffusion dynamics that precipitation patterns could be adequately controlled by adjusting the permeability fluctuations within the gel structure. The findings of this study lead to a greater understanding of the spontaneous creation of precipitation patterns by a system driven by disorder.

| S-EPMC6645417 | biostudies-literature

Adiabatic far-field sub-diffraction imaging.

Project description:The limited resolution of a conventional optical imaging system stems from the fact that the fine feature information of an object is carried by evanescent waves, which exponentially decays in space and thus cannot reach the imaging plane. We introduce here an adiabatic lens, which utilizes a geometrically conformal surface to mediate the interference of slowly decompressed electromagnetic waves at far field to form images. The decompression is satisfying an adiabatic condition, and by bridging the gap between far field and near field, it allows far-field optical systems to project an image of the near-field features directly. Using these designs, we demonstrated the magnification can be up to 20 times and it is possible to achieve sub-50 nm imaging resolution in visible. Our approach provides a means to extend the domain of geometrical optics to a deep sub-wavelength scale.

| S-EPMC4839783 | biostudies-literature

Spin-orbit torque-driven propagating spin waves.

Project description:Spin-orbit torque (SOT) can drive sustained spin wave (SW) auto-oscillations in a class of emerging microwave devices known as spin Hall nano-oscillators (SHNOs), which have highly nonlinear properties governing robust mutual synchronization at frequencies directly amenable to high-speed neuromorphic computing. However, all demonstrations have relied on localized SW modes interacting through dipolar coupling and/or direct exchange. As nanomagnonics requires propagating SWs for data transfer and additional computational functionality can be achieved using SW interference, SOT-driven propagating SWs would be highly advantageous. Here, we demonstrate how perpendicular magnetic anisotropy can raise the frequency of SOT-driven auto-oscillations in magnetic nanoconstrictions well above the SW gap, resulting in the efficient generation of field and current tunable propagating SWs. Our demonstration greatly extends the functionality and design freedom of SHNOs, enabling long-range SOT-driven SW propagation for nanomagnonics, SW logic, and neuromorphic computing, directly compatible with CMOS technology.

| S-EPMC6868678 | biostudies-literature

Cascaded counter-propagating nonlinear interactions in highly-efficient sub-µm periodically poled crystals.

Project description:Mirrorless optical parametric oscillators (MOPOs) are very attractive parametric devices that rely on the nonlinear interaction of counter-propagating photons to inherently establish distributed feedback, without the use of external mirrors or surface coatings. These devices offer unique spectral and coherence properties that will benefit a large variety of applications ranging from spectroscopy to quantum communications. The major obstacle in exploiting their full potential is ascribed to the difficulty in engineering a nonlinear material in which the generation of counter-propagating waves can be phase matched. Here we present a reliable and consistent technique for fabrication of highly-efficient sub-micrometer periodically poled Rb-doped KTiOPO4. We experimentally demonstrate the first cascaded counter-propagating interactions in which the generated forward signal serves as a pump for a secondary MOPO process, reaching pump depletion larger than 60%. The cascaded process exemplifies the high efficiency of our nonlinear photonic structures. Our domain-engineering technique paves the way to realize counter-propagating schemes and devices that have been deemed unfeasible until now.

| S-EPMC5556100 | biostudies-other

Shear modulus imaging by direct visualization of propagating shear waves with phase-sensitive optical coherence tomography.

Project description:We propose an integrated method combining low-frequency mechanics with optical imaging to map the shear modulus within the biological tissue. Induced shear wave propagating in tissue is tracked in space and time using phase-sensitive optical coherence tomography (PhS-OCT). Local estimates of the shear-wave speed obtained from tracking results can image the local shear modulus. A PhS-OCT system remotely records depth-resolved, dynamic mechanical waves at an equivalent frame rate of ?47??kHz with the high spatial resolution. The proposed method was validated by examining tissue-mimicking phantoms made of agar and light scattering material. Results demonstrate that the shear wave imaging can accurately map the elastic moduli of these phantoms.

| S-EPMC4019419 | biostudies-literature

Propagating waves of self-assembly in organosilane monolayers.

Project description:Wavefronts associated with reaction-diffusion and self-assembly processes are ubiquitous in the natural world. For example, propagating fronts arise in crystallization and diverse other thermodynamic ordering processes, in polymerization fronts involved in cell movement and division, as well as in the competitive social interactions and population dynamics of animals at much larger scales. Although it is often claimed that self-sustaining or autocatalytic front propagation is well described by mean-field "reaction-diffusion" or "phase field" ordering models, it has recently become appreciated from simulations and theoretical arguments that fluctuation effects in lower spatial dimensions can lead to appreciable deviations from the classical mean-field theory (MFT) of this type of front propagation. The present work explores these fluctuation effects in a real physical system. In particular, we consider a high-resolution near-edge x-ray absorption fine structure spectroscopy (NEXAFS) study of the spontaneous frontal self-assembly of organosilane (OS) molecules into self-assembled monolayer (SAM) surface-energy gradients on oxidized silicon wafers. We find that these layers organize from the wafer edge as propagating wavefronts having well defined velocities. In accordance with two-dimensional simulations of this type of front propagation that take fluctuation effects into account, we find that the interfacial widths w(t) of these SAM self-assembly fronts exhibit a power-law broadening in time, w(t) approximately t(beta), rather than the constant width predicted by MFT. Moreover, the observed exponent values accord rather well with previous simulation and theoretical estimates. These observations have significant implications for diverse types of ordering fronts that occur under confinement conditions in biological or materials-processing contexts.

| S-EPMC1965512 | biostudies-literature

Optical imaging of mitochondrial function uncovers actively propagating waves of mitochondrial membrane potential collapse across intact heart.

Project description:Polarization of the mitochondrial membrane potential (DeltaPsi(m)) is critical for normal mitochondrial function and cellular energetics. Mitochondrial dysfunction, manifesting as disrupted DeltaPsi(m) polarization (i.e. depolarization or hyperpolarization), underlies several important and highly prevalent diseases, including a variety of cardiac and neurological disorders. As such, DeltaPsi(m) instability might form a unifying mechanism for a class of metabolic disorders affecting excitable tissues. Here, we measured the spatio-temporal kinetics of DeltaPsi(m) changes across the intact heart using high-resolution optical DeltaPsi(m) imaging and uncovered surprisingly complex spatial patterns and dynamically fluctuating changes in DeltaPsi(m) that developed into actively propagating waves of mitochondrial depolarization during global ischemia. Our data further indicated that the recovery of DeltaPsi(m) upon reperfusion is dictated by the duration of the preceding ischemic insult. Post-ischemic electrical and functional recovery was dependent on early DeltaPsi(m) recovery but independent of overall cellular injury measured using a standard assay of lactate dehydrogenase release. These findings reveal a novel mechanism by which instabilities in cellular energetic properties that are independent of irreversible cellular injury can scale to the level of the intact organ via an organized process of active conduction involving the multi-cellular network. This highlights the importance of investigating cellular metabolic properties in the context of the intact organ.

| S-EPMC3081287 | biostudies-literature

Longitudinally propagating traveling waves of the mammalian tectorial membrane.

Project description:Sound-evoked vibrations transmitted into the mammalian cochlea produce traveling waves that provide the mechanical tuning necessary for spectral decomposition of sound. These traveling waves of motion that have been observed to propagate longitudinally along the basilar membrane (BM) ultimately stimulate the mechano-sensory receptors. The tectorial membrane (TM) plays a key role in this process, but its mechanical function remains unclear. Here we show that the TM supports traveling waves that are an intrinsic feature of its visco-elastic structure. Radial forces applied at audio frequencies (2-20 kHz) to isolated TM segments generate longitudinally propagating waves on the TM with velocities similar to those of the BM traveling wave near its best frequency place. We compute the dynamic shear storage modulus and shear viscosity of the TM from the propagation velocity of the waves and show that segments of the TM from the basal turn are stiffer than apical segments are. Analysis of loading effects of hair bundle stiffness, the limbal attachment of the TM, and viscous damping in the subtectorial space suggests that TM traveling waves can occur in vivo. Our results show the presence of a traveling wave mechanism through the TM that can functionally couple a significant longitudinal extent of the cochlea and may interact with the BM wave to greatly enhance cochlear sensitivity and tuning.

| S-EPMC2034249 | biostudies-literature

Formins specify membrane patterns generated by propagating actin waves.

Project description:Circular actin waves separate two distinct areas on the substrate-attached cell surface from each other: an external area from an inner territory that is circumscribed by the wave. These areas differ in composition of actin-associated proteins and of phosphoinositides in the membrane. At the propagating wave, one area is converted into the other. By photo-conversion of Eos-actin and analysis of actin network structures we show that both in the inner territory and the external area the actin network is subject to continuous turnover. To address the question of whether areas in the wave pattern are specified by particular actin polymerizing machines, we locate five members of the formin family to specific regions of the wave landscape using TIRF microscopy and constitutively active formin constructs tagged with fluorescent protein. Formin ForB favors the actin wave and ForG the inner territory, whereas ForA, ForE, and ForH are more strongly recruited to the external area. Fluctuations of membrane binding peculiar to ForB indicate transient states in the specification of membrane domains before differentiation into ForB decorated and depleted ones. Annihilation of the patterns by 1 µM of the formin inhibitor SMIFH2 supports the implication of formins in their generation.

| S-EPMC7183788 | biostudies-literature

Diffraction-Free Bloch Surface Waves.

Project description:Here, we demonstrate a diffraction-free Bloch surface wave sustained on all-dielectric multilayers that does not diffract after being passed through three obstacles or across a single mode fiber. It can propagate in a straight line for distances longer than 110 ?m at a wavelength of 633 nm and could be applied as an in-plane optical virtual probe both in air and in an aqueous environment. Its ability to be used in water, its long diffraction-free distance, and its tolerance to multiple obstacles make this wave ideal for certain applications in areas such as the biological sciences, where many measurements are made on glass surfaces or for which an aqueous environment is required, and for high-speed interconnections between chips, where low loss is necessary.

| S-EPMC5777330 | biostudies-literature

OmicsDI is part of the ELIXIR infrastructure

OmicsDI is an Elixir interoperability service. Learn more ›

Tweets

OmicsDI Databases

PRIDE
PeptideAtlas
MassIVE
JPOST Repository
Physiome Model Repository

EGA
EVA
ENA
LINCS
PAXDB
Cell Collective

MetaboLights
Metabolomics Workbench
MetabolomeExpress
GNPS
BioModels
FAIRDOMHub

ArrayExpress
dbGaP
ExpressionAtlas
GEO
NODE

Information

Databases
Help
API
Contact us
Code on GitHub
Terms of use
Submit Data