Browsing by Author "RAKOVICH, YURY"
Now showing items 1-20 of 51
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Absorption and photoluminescence study of CdS quantum dots: the role of host matrix and nanocrystal size and density
RAKOVICH, YURY (Materials Research Society, 1999) -
Amplified spontaneous emission from a microtube cavity with whispering gallery modes
DONEGAN, JOHN; PEROVA, TANIA; RAKOVICH, YURY; GOUNKO, IOURI (2007)We present a detailed study of the photonic modes in microtube cavity of ~ 7-8 ?m outer diameter that can act as micron-scale optical cylindrical resonator. We demonstrate a new route to the fabrication of individual ... -
CdTe Quantum Dot/Dye Hybrid System as Photosensitizer for Photodynamic Therapy
DONEGAN, JOHN; RAKOVICH, YURY (2010)We have studied the photodynamic properties of novel CdTe quantum dots?methylene blue hybrid photosensitizer. Absorption spectroscopy, photolumines- cence spectroscopy, and fluorescence lifetime imaging of this system ... -
Confined modes in photonic microtube structures.
RAKOVICH, YURY; PEROVA, TANIA; DONEGAN, JOHN; MOORE, ROBERT (SPIE, 2007)We present the results of studies on small photonic microtube structures of less than 10 microns diameter. A new technique based on vacuum assisted filtration is used to produce the microtube resonantors. Whispering gallery ... -
Confined optical modes and amplified spontaneous emission from a microtube cavity formed by vacumm assisted filtration
GOUNKO, IOURI; DONEGAN, JOHN FRANCIS; PEROVA, TANIA; RAKOVICH, YURY (American Physical Society, 2006)The authors demonstrate a new route to the fabrication of individual aluminosilicate microtubes that can act as micron-scale optical cylindrical resonators. The microtubes were prepared using a simple vacuum assisted wetting ... -
Conical diffraction and Bessel beam formation with a high optical quality biaxial crystal
DONEGAN, JOHN; LUNNEY, JAMES; RAKOVICH, YURY (2009)The manipulation of a Gaussian laser beam using conical diffraction in a high optical quality biaxial crystal of KGd(WO4)2 has been examined in detail with emphasis on the experimental techniques involved and intuitive ... -
Conical diffraction of linearly polarised light controls the angular position of a microscopic object
LUNNEY, JAMES; DONEGAN, JOHN; RAKOVICH, YURY; PHELAN, CIARAN; BALLANTINE, KYLE (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 ... -
The creation and annihilation of optical vortices using cascade conical diffraction
LUNNEY, JAMES; DONEGAN, JOHN; PHELAN, CIARAN; RAKOVICH, YURY; EASTHAM, PAUL (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 ... -
Effect of self-defocusing in thin films of close-packed CdS nanocrystals
RAKOVICH, YURY (World Scientific, 1999) -
Effect of static electric field on luminescence spectra of quantum-size CdS, PbI2 particles and CdS monocrystals
RAKOVICH, YURY (1995)The influence of static electric field on the luminescence spectra of quantum confined CdS and Pbl2 particles as well as bulk CdS monocrystals has been studied in this work. The applied electric field causes the increase ... -
Effect of ZnS Shell Thickness on the Phonon Spectra in CdSe Quantum Dots
DONEGAN, JOHN FRANCIS; RAKOVICH, YURY; MOORE, ALAN; PEROVA, TANIA (The American Physical Society, 2003)The evolution of the optical phonon spectra of colloidal core/shell CdSe/ZnS quantum dots with an increase of the shell thickness from 0.5 to 3.4 monolayers has been studied by resonant Raman spectroscopy. The results ... -
Effect of ZnS shell thickness on the phonon spectra in CdSe quantum dots
RAKOVICH, YURY (American Physical Society, 2003)The evolution of the optical phonon spectra of colloidal core/shell CdSe/ZnS quantum dots with an increase of the shell thickness from 0.5 to 3.4 monolayers has been studied by resonant Raman spectroscopy. The results ... -
Emission Properties of Colloidal Quantum Dots on Polyelectrolyte Multilayers
BRADLEY, LOUISE; GOUNKO, IOURI; RAKOVICH, YURY (2006)We present steady state and time-resolved photoluminescence (PL) characteristics of differently charged CdTe quantum dots (QDs) adsorbed onto a polyelectrolyte (PE) multilayer. The PE multilayer is built up using a ... -
Energy transfer processes in semiconductor quantum dots: bacteriorhodopsin hybrid system
DONEGAN, JOHN; RAKOVICH, YURY (2009)The potential impact of nanoscience on energy transfer processes in biomolecules was investigated on the example of a complex between fluorescent semiconductor nanocrystals and photochromic membrane protein. The ... -
Enhanced coupling of electronic and photonic states in a microcavity-quantum dot system
DONEGAN, JOHN; RAKOVICH, YURY (2005)Spherical microcavities consisting of a dielectric material show unique optical characteristics as resonators in combination with semiconductor nanoparticles. A high quality factor results in a very narrow bandwidth of the ... -
Enhancement of photoluminescence intensity of CdS(Se) nanocrystal thin films
RAKOVICH, YURY (INOE Publishing House, 2000) -
Fine structure of coupled optical modes in photonic molecules
RAKOVICH, YURY; BRADLEY, LOUISE (2004)We report on the coherent coupling of whispering gallery modes (WGM) in a photonic molecule formed from two melamine-formaldehyde spherical microcavities with a thin shell of CdTe nanocrystals. Utilizing a microporous ... -
FIR absorption in CdSe quantum dot ensembles
RAKOVICH, YURY (Wiley & Sons, 2001)Absorption of far-infrared (FIR) radiation in very small CdSe crystallites (quantum dots, QDs) via excitation of confined dipolar vibrational modes was studied, both theoretically and experimentally. Spatial quantisation ... -
Free Exciton Spectra in Heteroepitaxial ZnSe/GaAs layers
RAKOVICH, YURY (American Physical Society, 2000)The free-exciton photoluminescence (PL) and reflection spectra of metal-organic vapor-phase-epitaxy grown ZnSe/GaAs epilayers with a thickness greater than that of the strain relaxation thickness were studied experimentally ... -
Generation of continuously tunable fractional optical orbital angular momentum using internal conical diffraction
DONEGAN, JOHN; PHELAN, CIARAN; LUNNEY, JAMES; RAKOVICH, YURY (2010)When a left-circularly polarised Gaussian light beam, which has spin angular momentum (SAM) J sp = ? ? = 1 ? per photon, is incident along one of the optic axes of a slab of biaxial crystal it undergoes internal ...