1,305,006 research outputs found
Surface optical vortices
It is shown how the total internal reflection of orbital-angular-momentum-endowed light can lead to the generation of evanescent light possessing rotational properties in which the intensity distribution is firmly localized in the vicinity of the surface. The characteristics of these surface optical vortices depend on the form of the incident light and on the dielectric mismatch of the two media. The interference of surface optical vortices is shown to give rise to interesting phenomena, including pattern rotation akin to a surface optical Ferris wheel. Applications are envisaged to be in atom lithography, optical surface tweezers, and spanners
Multiple pass reimaging optical system
An optical imaging system for enabling nonabsorbed light imaged onto a photodetective surface to be collected and reimaged one or more times onto that surface in register with the original image. The system includes an objective lens, one or more imaging lenses, one or more retroreflectors and perhaps a prism for providing optical matching of the imaging lens focal planes to the photo detective surface
Measuring the role of surface chemistry in silicon microphotonics
Utilizing a high quality factor (Q~1.5×10^6) optical microresonator to provide sensitivity down to a fractional surface optical loss of alphas[prime]~10^–7, we show that the optical loss within Si microphotonic components can be dramatically altered by Si surface preparation, with alphas[prime]~1×10^–5 measured for chemical oxide surfaces as compared to alphas[prime]<=1×10^–6 for hydrogen-terminated Si surfaces. These results indicate that the optical properties of Si surfaces can be significantly and reversibly altered by standard microelectronic treatments, and that stable, high optical quality surface passivation layers will be critical in future Si micro- and nanophotonic systems
Contribution of the Internal Field to the Anisotropic Optical Reflectance of GaP(110)
This article presents the theory of optical reflection from thin slabs of GaP(110) by means of the discrete dipole model and focusses especially upon the possible implications of this model for the surface induced optical anisotropy. The reflectance of a semi-infinite sample is extracted from slab calculations and compared with experiments. We find that the internal field has a very important role in determining the surface induced optical anisotropy. We also show that the surface sensitivity of such experiments can be estimated to be about five monolayer
Controlling quantum-dot light absorption and emission by a surface-plasmon field
The possibility for controlling the probe-field optical gain and absorption
switching and photon conversion by a surface-plasmon-polariton near field is
explored for a quantum dot above the surface of a metal. In contrast to the
linear response in the weak-coupling regime, the calculated spectra show an
induced optical gain and a triply-split spontaneous emission peak resulting
from the interference between the surface-plasmon field and the probe or
self-emitted light field in such a strongly-coupled nonlinear system. Our
result on the control of the mediated photon-photon interaction, very similar
to the `gate' control in an optical transistor, may be experimentally
observable and applied to ultra-fast intrachip/interchip optical interconnects,
improvement in the performance of fiber-optic communication networks and
developments of optical digital computers and quantum communications.Comment: 7 pages, 15 figure
Transformation Optics for Plasmonics
A new strategy to control the flow of surface plasmon polaritons at metallic
surfaces is presented. It is based on the application of the concept of
Transformation Optics to devise the optical parameters of the dielectric medium
placed on top of the metal surface. We describe the general methodology for the
design of Transformation-Optical devices for surface plasmons and analyze, for
proof-of-principle purposes, three representative examples with different
functionalities: a beam shifter, a cylindrical cloak and a ground-plane cloak.Comment: 15 pages, 3 figure
Surface polar optical phonon interaction induced many-body effects and hot-electron relaxation in graphene
We theoretically study various aspects of the electron-surface optical phonon
interaction effects in graphene on a substrate made of polar materials. We
calculate the electron self-energy in the presence of the surface
phonon-mediated electron-electron interaction focusing on how the linear chiral
graphene dispersion is renormalized by the surface phonons. The electron
self-energy as well as the quasiparticle spectral function in graphene are
calculated, taking into account electron-polar optical phonon interaction by
using a many body perturbative formalism. The scattering rate of free electrons
due to polar interaction with surface optical phonons in a dielectric substrate
is calculated as a function of the electron energy, temperatures, and carrier
density. Effects of screening on the self-energy and scattering rate are
discussed. Our theory provides a comprehensive quantitative (and qualitative)
picture for surface phonon interaction induced many-body effects and hot
electron relaxation in Dirac materials.Comment: 10 pages, 10 figure
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