Browsing by Subject "Optics"
Now showing items 1-20 of 45
-
Acceptance angle influence on optimum incident spot size for high-finesse microcavity two-photon absorption photodetectors
(2009)The influence of the limited acceptance angle of a high-finesse microcavity two-photon absorption photodetector on its response has been investigated. It is shown that the limited acceptance angle of the microcavity ... -
Conical diffraction of linearly polarised light controls the angular position of a microscopic object
(2010)Conical diffraction of linearly polarised light in a biaxial crystal produces a beam with a crescent-shaped intensity profile. Rotation of the plane of polarisation produces the unique effect of spatially moving the ... -
Conoscopy of chiral smectic liquid crystal cells
(2008)The conoscopic method for investigating the optical properties of a liquid crystal cell is studied with the aim of determining the effects of the approximations used in the calculation on the results. We confirm that the ... -
The creation and annihilation of optical vortices using cascade conical diffraction
(2011)Internal conical diffraction produces a superposition of orthogonally polarised zero- and first-order Bessel like beams from an incident circularly polarised Gaussian beam. For right-circularly polarised light, the first-order ... -
Design of three-component one-dimensional photonic crystals for alteration of optical contrast and omni-directional reflection
(2010)In this study, three-component One-Dimensional (1D) Photonic Crystal (PC) structures were investigated by modeling them as two-component PCs with an additional regular layer. The Gap Map approach and the Transfer Matrix ... -
Design, fabrication and optical characterization of Fabry-Pérot tunable resonator based on microstructured Si and liquid crystal
(2010)The results of a simulation of the optical properties of a silicon Fabry-Perot resonator (with liquid crystal filler in the cavity), operated on the shift of the interference bands in the infrared range are presented. The ... -
Design, fabrication and Optical Characterization of Multi-Component Photonic Crystals for Integrated Si Microphotonics
(2011)This paper reports on investigation and possible applications of the optical elements based on one-dimensional (1D) multi-component photonic crystal (PCs). The gap map approach and the transfer matrix method were used in ... -
Dielectric focusing elements for integrated optics
(Trinity College Dublin. School of Physics. Discipline of Physics, 2018)The ability to propagate light around a `circuit' on a single chip has an abundance of applications. Connecting different elements can bring huge functionality to a minuscule device---as evidenced by integrated electronic ... -
The Effect of Local Field Dispersion on the Spectral Characteristics of Nanosized Particles and their Composites
(Intech, 2011)Infrared (IR) spectroscopy of micro- and nanosized particles and their composites is currently one of the most important enabling technologies in the development of micro- and nanostructures and their application to ... -
Electrically tunable Fabry-Pérot resonator based on microstrcutured Si containing liquid crystal
(2012)We have built Fabry-Perot resonators based on mi-crostructured silicon and a liquid crystal. The devices exhibit tuning of the resonance peaks over a wide range, with relative spectral shifts of up to ??/? = 10%. In order ... -
Energy transfer in colloidal CdTe quantum dot nanoclusters
(2010)Quantum dot (QD) nanoclusters were formed using oppositely charged colloidal CdTe QDs, of two different sizes, mixed in aqueous solutions. The photoluminescence (PL) spectra and time-resolved PL decays show signatures of ... -
Evaluation of high frequency vibrations using electronic speckle pattern interferometry
(2002)The available techniques for the study of high frequency vibration using electronic speckle pattern interferometry (ESPI) are briefly surveyed. We concentrate on two methods in particular. The first is a straightforward ... -
Extracting the hysteresis loops of magnetic interfaces from optical second-harmonic intensity measurements
(2007)Surface- and interface-sensitive optical techniques, such as optical second-harmonic generation (SHG), allow the buried interfacial structure of centrosymmetric materials to be explored through thin capping layers, and ... -
Fabrication of one-dimensional photonic crystals by photoelectrochemical etching of silicon
(2010)The conditions of formation of deep periodic trenches by photoelectrochemical etching of n-Si (100) with linear seeds on the surface are analyzed. Criteria for the proper choice of the period of seed grooves and the etching ... -
Fabrication Technology of Heterojunctions in the Lattice of a 2D Photonic Crystal Based on Macroporous Silicon
(2011)Design and fabrication technology of a microcavity structure based on a double heterojunction in macroporous silicon is suggested. The fabrication process of a strip of a 2D photonic crystal constituted by a finite number ... -
FTIR study of a chiral tilted SmA liquid crystalline phase
(EDP Sciences, 2002)In this paper we present the results of the polarized infrared spectroscopy as evidence for the existence of a chiral analogue of the SmA phase of the de Vries type. In this phase, the molecular director in the smectic ... -
Generation of a radially polarized light beam using internal conical diffraction
(2011)Using a combination of internal conical diffraction and Mach-Zehnder interferometry we have theoretically and experimentally demonstrated an efficient new technique for the conversion of a linearly polarized Gaussian laser ... -
Generation of continuously tuneable fractional optical orbital angular momentum using internal conical diffraction
(2010)Abstract: When a left-circularly polarised Gaussian light beam, which has spin angular momentum (SAM) Jsp = ?? = 1? per photon, is incident along one of the optic axes of a slab of biaxial crystal it undergoes internal ... -
Graphene oxide covalently functionalized with zinc phthalocyanine for broadband optical limiting
(Elsevier, 2011)A soluble graphene oxide (GO) covalently functionalized with zinc phthalocyanine (PcZn), GO-PcZn, was synthesized by an amidation reaction. The formation of an amido bond between PcZn and GO has been confirmed by x-ray ...