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Garcia-Vidal F.J.,Autonomous University of Madrid | Martin-Moreno L.,University of Zaragoza | Ebbesen T.W.,University of Strasbourg | Kuipers L.,FOM Institute for Atomic and Molecular Physics
Reviews of Modern Physics | Year: 2010

This review provides a perspective on the recent developments in the transmission of light through subwavelength apertures in metal films. The main focus is on the phenomenon of extraordinary optical transmission in periodic hole arrays, discovered over a decade ago. It is shown that surface electromagnetic modes play a key role in the emergence of the resonant transmission. These modes are also shown to be at the root of both the enhanced transmission and beaming of light found in single apertures surrounded by periodic corrugations. This review describes both the theoretical and experimental aspects of the subject. For clarity, the physical mechanisms operating in the different structures considered are analyzed within a common theoretical framework. Several applications based on the transmission properties of subwavelength apertures are also addressed. © 2010 The American Physical Society.

Atwater H.A.,California Institute of Technology | Polman A.,FOM Institute for Atomic and Molecular Physics
Nature Materials | Year: 2010

The emerging field of plasmonics has yielded methods for guiding and localizing light at the nanoscale, well below the scale of the wavelength of light in free space. Now plasmonics researchers are turning their attention to photovoltaics, where design approaches based on plasmonics can be used to improve absorption in photovoltaic devices, permitting a considerable reduction in the physical thickness of solar photovoltaic absorber layers, and yielding new options for solar-cell design. In this review, we survey recent advances at the intersection of plasmonics and photovoltaics and offer an outlook on the future of solar cells based on these principles.

Chughtai K.,FOM Institute for Atomic and Molecular Physics | Heeren R.M.A.,FOM Institute for Atomic and Molecular Physics
Chemical Reviews | Year: 2010

Mass spectrometry (MS) is a great scientific tool due to its capabilities to determine the mass of large biomolecular complexes, individual biomolecules, small organic molecules, and single atoms and their isotopes has been reported. It emerged as a response to the demand for spatial information about biomolecules detected by conventional mass spectrometry. The third ionization method used for MSI evolved recently in the form of desorption electrospray ionization (DESI). Mass spectrometric imaging is essentially a four step process. It involves sample preparation, desorption and ionization, mass analysis, and image registration. Matrix-assisted laser desorption/ionization mass spectrometry (MALDI-MS) is a dramatic improvement of laser desorption/ionization mass spectrometry (LDI-MS). MSI provides two-dimensional distributions of multiple ions detected from biological samples. Cross-sectional views of the 3D models can be used to investigate distributions of many additional molecules detected by MSI.

Mann S.A.,FOM Institute for Atomic and Molecular Physics | Garnett E.C.,FOM Institute for Atomic and Molecular Physics
Nano Letters | Year: 2013

Metallic and dielectric nanostructures have highly tunable resonances that have been used to increase light absorption in a variety of photovoltaic materials and device structures. Metal nanowires have also emerged as a promising candidate for high-performance transparent electrodes for local contacts. In this Letter we propose combining these electrical and optical functions. As a first step, we use rigorous solutions to Maxwell's equations to demonstrate theoretically extreme absorption in semiconductor thin films wrapped around metal nanowires. We show that there are two key principles underlying this extraordinary light trapping effect: (1) maximizing the absorption of each individual resonance by ensuring it is critically coupled and (2) increasing the total number of degenerate resonances. Inserting a metal core into a semiconductor nanowire creates such a degeneracy: polarization-dependent Mie resonances are transformed into polarization-independent Fabry-Pérot-like resonances. We demonstrate that, by reducing the polarization sensitivity and increasing the number of critically coupled modes, this hybrid coaxial nanowire geometry substantially outperforms solid semiconducting nanowires, even though the semiconductor volume is significantly reduced. These results suggest that metal nanowires with semiconductor shells might be ideal building blocks for photovoltaic and solar fuel applications. © 2013 American Chemical Society.

Rotenberg N.,FOM Institute for Atomic and Molecular Physics | Kuipers L.,FOM Institute for Atomic and Molecular Physics
Nature Photonics | Year: 2014

The control of light fields on subwavelength scales in nanophotonic structures has become ubiquitous, driven by both curiosity and a multitude of applications in fields ranging from biosensing to quantum optics. Mapping these fields in detail is crucial, as theoretical modelling is far from trivial and highly dependent on nanoscale geometry. Recent developments of nanoscale field mapping, particularly with near-field microscopy, have not only led to a vastly increased resolution, but have also resulted in increased functionality. The phase and amplitude of different vector components of both the electric and magnetic fields are now accessible, as is the ultrafast temporal or spectral evolution of propagating pulses in nanostructures. In this Review we assess the current state-of-the-art of subwavelength light mapping, highlighting the new science and nanostructures that have subsequently become accessible. © 2014 Macmillan Publishers Limited. All rights reserved.

Koenderink A.F.,FOM Institute for Atomic and Molecular Physics
Optics Letters | Year: 2010

The Purcell factor is the standard figure of merit for spontaneous emission enhancement in microcavities and has also been proposed to describe emission enhancements for plasmonic resonances. A comparison of quality factor, mode volume, and Purcell factor for single and coupled plasmon spheres to exact calculations of emission rates shows that a Purcell factor derived from quality factor and mode volume does not describe emission changes due to plasmon antennas. © 2010 Optical Society of America.

Govern C.C.,FOM Institute for Atomic and Molecular Physics | Ten Wolde P.R.,FOM Institute for Atomic and Molecular Physics
Proceedings of the National Academy of Sciences of the United States of America | Year: 2014

Living cells deploy many resources to sense their environments, including receptors, downstream signaling molecules, time, and fuel. However, it is not known which resources fundamentally limit the precision of sensing, like weak links in a chain, and which can compensate each other, leading to trade-offs between them. We present a theory for the optimal design of the large class of sensing systems in which a receptor drives a push-pull network. The theory identifies three classes of resources that are required for sensing: receptors and their integration time, readout molecules, and energy (fuel turnover). Each resource class sets a fundamental sensing limit, which means that the sensing precision is bounded by the limiting resource class and cannot be enhanced by increasing another class-the different classes cannot compensate each other. This result yields a previously unidentified design principle, namely that of optimal resource allocation in cellular sensing. It states that, in an optimally designed sensing system, each class of resources is equally limiting so that no resource is wasted. We apply our theory to what is arguably the best-characterized sensing system in biology, the chemotaxis network of Escherichia coli. Our analysis reveals that this system obeys the principle of optimal resource allocation, indicating a selective pressure for the efficient design of cellular sensing systems.

Dogterom M.,FOM Institute for Atomic and Molecular Physics
Current opinion in cell biology | Year: 2013

Microtubules organize into a set of distinct patterns with the help of associated molecules that control nucleation, polymerization, crosslinking, and transport. These patterns, alone or in combination with each other, define the functional architecture of the microtubule cytoskeleton in living cells. In vitro experiments of increasing complexity help understand, in combination with theoretical models, the basic mechanisms by which elementary microtubule patterns arise, how they are maintained, and how they position themselves with respect to the confining geometry of living cells. Copyright © 2012 Elsevier Ltd. All rights reserved.

Bakker H.J.,FOM Institute for Atomic and Molecular Physics | Skinner J.L.,University of Wisconsin - Madison
Chemical Reviews | Year: 2010

The experimental technique of vibrational spectroscopy and the role that it has played in elucidating the structure and dynamics of liquid water in thermal equilibrium was investigated. Considering first the Raman line shapes, theoretical analysis indicates that the shoulder on the blue side is due to HOD molecules lacking an H-bond to the H/D atom for HDO:D2O/HDO:H 2O, respectively. The spectral diffusion observables provide quite direct information about the frequency-frequency time-correlation function. Integrated three-pulse echo-peak shift experiments show that the correlation function has an initial inertial time decay within 50 fs, a recurrence indicative of an underdamped oscillation at about 180 fs, and a long-time decay with a time constant of about 1.4 ps. As in the case of liquid water, the exquisite sensitivity of OH stretch vibrational frequencies to local environments, coupled with the excellent time and frequency resolution of modern ultrafast vibrational spectroscopy, make this an excellent technique for unraveling complicated structural and dynamical issues.

Polman A.,FOM Institute for Atomic and Molecular Physics
ACS Nano | Year: 2013

Silica-gold core-shell nanoparticles that are immersed in water act as efficient nanoscale generators of steam when illuminated with sunlight. In their paper in this issue of ACS Nano, Halas, Nordlander, and co-workers demonstrate this intriguing phenomenon that results from the nucleation of steam at the surface of individual nanoparticles that are heated by the sun. The same effect is also used to demonstrate distillation of ethanol. The solar steam nanobubble generation phenomenon results from the complex interplay of many different phenomena that occur at the nanoscale, and can find a broad range of applications. © 2013 American Chemical Society.

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