268 Works

Compression of 3D color integral images

Sekwon Yeom, Adrian Stern & Bahram Javidi
In this paper, we discuss the compression results of full color 3D Integral Images (II) by MPEG-2 (Motion Picture Experts Group). II is a popular three-dimensional image video recording and display technique. The huge size of II data has become a practical issue for storing and transmitting of 3D scenes. The MPEG is a standard coded representation of moving pictures. We model the elemental images in II as consecutive frames in a moving picture. Therefore,...

Compression of 3D color integral images

Sekwon Yeom, Adrian Stern & Bahram Javidi
In this paper, we discuss the compression results of full color 3D Integral Images (II) by MPEG-2 (Motion Picture Experts Group). II is a popular three-dimensional image video recording and display technique. The huge size of II data has become a practical issue for storing and transmitting of 3D scenes. The MPEG is a standard coded representation of moving pictures. We model the elemental images in II as consecutive frames in a moving picture. Therefore,...

One-unit system for electroholography by use of a special-purpose computational chip with a high-resolution liquid-crystal display toward a three-dimensional television

Tomoyoshi Ito & Tomoyoshi Shimobaba
We developed a one-unit system for electroholography, which consists of a special-purpose computational chip and a high-resolution, reflective mode, liquid-crystal display panel as a spatial light modulator. We implemented them on one board whose size is approximately 20 cm × 20 cm. The chip makes a computer-generated hologram whose size is 800 × 600 at nearly real time (~0.5 s) for an object consisting of 1000 points. The pixel pitch of the display panel is...

One-unit system for electroholography by use of a special-purpose computational chip with a high-resolution liquid-crystal display toward a three-dimensional television

Tomoyoshi Ito & Tomoyoshi Shimobaba
We developed a one-unit system for electroholography, which consists of a special-purpose computational chip and a high-resolution, reflective mode, liquid-crystal display panel as a spatial light modulator. We implemented them on one board whose size is approximately 20 cm × 20 cm. The chip makes a computer-generated hologram whose size is 800 × 600 at nearly real time (~0.5 s) for an object consisting of 1000 points. The pixel pitch of the display panel is...

Gas visualization of industrial hydrocarbon emissions

Jonas Sandsten, Hans Edner & Sune Svanberg
Gases leaking from a polyethene plant and a cracker plant were visualized with the gas-correlation imaging technique. Ethene escaping from flares due to incomplete or erratic combustion was monitored. A leakage at a high-pressure reactor tank could be found and visualized by scanning the camera system over the industrial site. The image processing methods rely on the information from three simultaneously captured images. A direct and a gas-filtered infrared image are recorded with a split-mirror...

Gas visualization of industrial hydrocarbon emissions

Jonas Sandsten, Hans Edner & Sune Svanberg
Gases leaking from a polyethene plant and a cracker plant were visualized with the gas-correlation imaging technique. Ethene escaping from flares due to incomplete or erratic combustion was monitored. A leakage at a high-pressure reactor tank could be found and visualized by scanning the camera system over the industrial site. The image processing methods rely on the information from three simultaneously captured images. A direct and a gas-filtered infrared image are recorded with a split-mirror...

In-situ visualization, monitoring and analysis of electric field domain reversal process in ferroelectric crystals by digital holography

Simonetta Grilli, Pietro Ferraro, Melania Paturzo, Domenico Alfieri, Paolo De Natale, Marella De Angelis, Sergio De Nicola, Andrea Finizio & Giovanni Pierattini
In-situ monitoring of domain reversal in congruent lithium niobate by a digital holographic technique is described. While the ferroelectric polarization is reversed by electric field poling, the two-dimensional distribution of the phase shift, due mainly to the linear electro-optic and piezoelectric effects, is measured and visualized. Digital holography is used to reconstruct both amplitude and phase of the wavefield transmitted by the sample to reveal the phase shift induced by adjacent reversed domains during the...

In-situ visualization, monitoring and analysis of electric field domain reversal process in ferroelectric crystals by digital holography

Simonetta Grilli, Pietro Ferraro, Melania Paturzo, Domenico Alfieri, Paolo De Natale, Marella De Angelis, Sergio De Nicola, Andrea Finizio & Giovanni Pierattini
In-situ monitoring of domain reversal in congruent lithium niobate by a digital holographic technique is described. While the ferroelectric polarization is reversed by electric field poling, the two-dimensional distribution of the phase shift, due mainly to the linear electro-optic and piezoelectric effects, is measured and visualized. Digital holography is used to reconstruct both amplitude and phase of the wavefield transmitted by the sample to reveal the phase shift induced by adjacent reversed domains during the...

Supercontinuum generation in a photonic crystal fiber with two zero dispersion wavelengths

Karen Marie Hilligsøe, Thomas Vestergaard Andersen, Henrik Nørgaard Paulsen, Carsten Krogh Nielsen, Klaus Mølmer, Søren Keiding, Rene Kristiansen, Kim Per Hansen & Jakob Juul Larsen
We demonstrate supercontinuum generation in a highly nonlinear photonic crystal fiber with two closely lying zero dispersion wavelengths. The special dispersion of the fiber has a profound influence on the supercontinuum which is generated through self-phase modulation and phasematched four-wave mixing and not soliton fission as in the initial photonic crystal fibers. The supercontinuum has high spectral density and is extremely independent of the input pulse over a wide range of input pulse parameters. Simulations...

Supercontinuum generation in a photonic crystal fiber with two zero dispersion wavelengths

Karen Marie Hilligsøe, Thomas Vestergaard Andersen, Henrik Nørgaard Paulsen, Carsten Krogh Nielsen, Klaus Mølmer, Søren Keiding, Rene Kristiansen, Kim Per Hansen & Jakob Juul Larsen
We demonstrate supercontinuum generation in a highly nonlinear photonic crystal fiber with two closely lying zero dispersion wavelengths. The special dispersion of the fiber has a profound influence on the supercontinuum which is generated through self-phase modulation and phasematched four-wave mixing and not soliton fission as in the initial photonic crystal fibers. The supercontinuum has high spectral density and is extremely independent of the input pulse over a wide range of input pulse parameters. Simulations...

Topology optimization and fabrication of photonic crystal structures

P. I. Borel, A. Harpøth, L. H. Frandsen, M. Kristensen, P. Shi, J. S. Jensen & O. Sigmund
Topology optimization is used to design a planar photonic crystal waveguide component resulting in significantly enhanced functionality. Exceptional transmission through a photonic crystal waveguide Z-bend is obtained using this inverse design strategy. The design has been realized in a silicon-on-insulator based photonic crystal waveguide. A large low loss bandwidth of more than 200 nm for the TE polarization is experimentally confirmed.

Topology optimization and fabrication of photonic crystal structures

P. I. Borel, A. Harpøth, L. H. Frandsen, M. Kristensen, P. Shi, J. S. Jensen & O. Sigmund
Topology optimization is used to design a planar photonic crystal waveguide component resulting in significantly enhanced functionality. Exceptional transmission through a photonic crystal waveguide Z-bend is obtained using this inverse design strategy. The design has been realized in a silicon-on-insulator based photonic crystal waveguide. A large low loss bandwidth of more than 200 nm for the TE polarization is experimentally confirmed.

High quality-factor whispering-gallery mode in the photonic crystal hexagonal disk cavity

Han-Youl Ryu, Masaya Notomi, Guk-Hyun Kim & Yong-Hee Lee
We study whispering-gallery-like modes in photonic crystal air-bridge slab micro-cavities having H2 defects using finite-difference time-domain calculations. The defect geometry is optimized to increase the quality factor (Q) of the H2-cavity whispering-gallery mode (WGM). By symmetrically distributing 12 nearest neighbor holes around the defect and controlling size of holes, it is possible to drastically increase the Q of >105 while preserving effective mode volume of the order of the cubic wavelength in material. In addition,...

High quality-factor whispering-gallery mode in the photonic crystal hexagonal disk cavity

Han-Youl Ryu, Masaya Notomi, Guk-Hyun Kim & Yong-Hee Lee
We study whispering-gallery-like modes in photonic crystal air-bridge slab micro-cavities having H2 defects using finite-difference time-domain calculations. The defect geometry is optimized to increase the quality factor (Q) of the H2-cavity whispering-gallery mode (WGM). By symmetrically distributing 12 nearest neighbor holes around the defect and controlling size of holes, it is possible to drastically increase the Q of >105 while preserving effective mode volume of the order of the cubic wavelength in material. In addition,...

Interactive application in holographic optical tweezers of a multi-plane Gerchberg-Saxton algorithm for three-dimensional light shaping

Gavin Sinclair, Jonathan Leach, Pamela Jordan, Graham Gibson, Eric Yao, Zsolt John Laczik, Miles J. Padgett & Johannes Courtial
Phase-hologram patterns that can shape the intensity distribution of a light beam in several planes simultaneously can be calculated with an iterative Gerchberg-Saxton algorithm [T. Haist et al., Opt. Commun. 140, 299 (1997)]. We apply this algorithm in holographic optical tweezers. This allows us to simultaneously trap several objects in individually controllable arbitrary 3-dimensional positions. We demonstrate the interactive use of our approach by trapping microscopic spheres and moving them into an arbitrary 3-dimensional configuration.

Interactive application in holographic optical tweezers of a multi-plane Gerchberg-Saxton algorithm for three-dimensional light shaping

Gavin Sinclair, Jonathan Leach, Pamela Jordan, Graham Gibson, Eric Yao, Zsolt John Laczik, Miles J. Padgett & Johannes Courtial
Phase-hologram patterns that can shape the intensity distribution of a light beam in several planes simultaneously can be calculated with an iterative Gerchberg-Saxton algorithm [T. Haist et al., Opt. Commun. 140, 299 (1997)]. We apply this algorithm in holographic optical tweezers. This allows us to simultaneously trap several objects in individually controllable arbitrary 3-dimensional positions. We demonstrate the interactive use of our approach by trapping microscopic spheres and moving them into an arbitrary 3-dimensional configuration.

Real-time interactive optical micromanipulation of a mixture of high- and low-index particles

Peter John Rodrigo, Vincent Ricardo Daria & Jesper Glückstad
We demonstrate real-time interactive optical micromanipulation of a colloidal mixture consisting of particles with both lower (nLn0) refractive indices than that of the suspending medium (n0). Spherical high- and low-index particles are trapped in the transverse plane by an array of confining optical potentials created by trapping beams with top-hat and annular cross-sectional intensity profiles, respectively. The applied method offers extensive reconfigurability in the spatial distribution and individual geometry of the optical traps. We experimentally...

Real-time interactive optical micromanipulation of a mixture of high- and low-index particles

Peter John Rodrigo, Vincent Ricardo Daria & Jesper Glückstad
We demonstrate real-time interactive optical micromanipulation of a colloidal mixture consisting of particles with both lower (nLn0) refractive indices than that of the suspending medium (n0). Spherical high- and low-index particles are trapped in the transverse plane by an array of confining optical potentials created by trapping beams with top-hat and annular cross-sectional intensity profiles, respectively. The applied method offers extensive reconfigurability in the spatial distribution and individual geometry of the optical traps. We experimentally...

Transverse modulational instabilities of counterpropagating solitons in photorefractive crystals

M. Belić, M. Petrović, D. Jović, A. Strinić, D. Arsenović, K. Motzek, F. Kaiser, Ph. Jander, C. Denz, M. Tlidi & Paul Mandel
We study numerically the counterpropagating vector solitons in SBN:60 photorefractive crystals. A simple theory is provided for explaining the symmetry-breaking transverse instability of these solitons. Phase diagram is produced that depicts the transition from stable counterpropagating solitons to bidirectional waveguides to unstable optical structures. Numerical simulations are performed that predict novel dynamical beam structures, such as the standing-wave and rotating multipole vector solitonic clusters. For larger coupling strengths and/or thicker crystals the beams form unstable...

Transverse modulational instabilities of counterpropagating solitons in photorefractive crystals

M. Belić, M. Petrović, D. Jović, A. Strinić, D. Arsenović, K. Motzek, F. Kaiser, Ph. Jander, C. Denz, M. Tlidi & Paul Mandel
We study numerically the counterpropagating vector solitons in SBN:60 photorefractive crystals. A simple theory is provided for explaining the symmetry-breaking transverse instability of these solitons. Phase diagram is produced that depicts the transition from stable counterpropagating solitons to bidirectional waveguides to unstable optical structures. Numerical simulations are performed that predict novel dynamical beam structures, such as the standing-wave and rotating multipole vector solitonic clusters. For larger coupling strengths and/or thicker crystals the beams form unstable...

Processing carbon nanotubes with holographic optical tweezers

Joseph Plewa, Evan Tanner, Daniel M. Mueth & David G. Grier
We report the first demonstration that carbon nanotubes can be trapped and manipulated by optical tweezers. This observation is surprising because individual nanotubes are substantially smaller than the wavelength of light, and thus should not be amenable to optical trapping. Even so, nanotube bundles, and perhaps even individual nanotubes, can be transported at high speeds, deposited onto substrates, untangled, and selectively ablated, all with visible light. The use of holographic optical tweezers, capable of creating...

Processing carbon nanotubes with holographic optical tweezers

Joseph Plewa, Evan Tanner, Daniel M. Mueth & David G. Grier
We report the first demonstration that carbon nanotubes can be trapped and manipulated by optical tweezers. This observation is surprising because individual nanotubes are substantially smaller than the wavelength of light, and thus should not be amenable to optical trapping. Even so, nanotube bundles, and perhaps even individual nanotubes, can be transported at high speeds, deposited onto substrates, untangled, and selectively ablated, all with visible light. The use of holographic optical tweezers, capable of creating...

Phosphorescence-Fluorescence ratio imaging for monitoring the oxygen status during photodynamic therapy

H. J. C. M. Sterenborg, J.W. De Wolf, M. Koning, B Kruijt, A. Van Den Heuvel & D. J. Robinson
The effectiveness of photodynamic therapy is strongly dependent on the availabilty of oxygen. In the present paper we show that the ratio between photosensitiser phosphorescence and fluorescence is a parameter that can be used to monitor the competition between singlet oxygen production and other processes quenching the photosensitiser triplet state. We present a theoretical basis for the validity of this approach and a series of in vitro imaging experiments.

Phosphorescence-Fluorescence ratio imaging for monitoring the oxygen status during photodynamic therapy

H. J. C. M. Sterenborg, J.W. De Wolf, M. Koning, B Kruijt, A. Van Den Heuvel & D. J. Robinson
The effectiveness of photodynamic therapy is strongly dependent on the availabilty of oxygen. In the present paper we show that the ratio between photosensitiser phosphorescence and fluorescence is a parameter that can be used to monitor the competition between singlet oxygen production and other processes quenching the photosensitiser triplet state. We present a theoretical basis for the validity of this approach and a series of in vitro imaging experiments.

Surface modes in air-core photonic band-gap fibers

James A. West, Charlene M. Smith, Nicholas F. Borrelli, Douglas C. Allan & Karl W. Koch
We present a detailed description of the role of surface modes in photonic band-gap fibers (PBGFs). A model is developed that connects the experimental observations of high losses in the middle of the transmission spectrum to the presence of surface modes supported at the core-cladding interface. Furthermore, a new PBGF design is proposed that avoids these surface modes and produces single-mode operation.

Resource Types

  • Collection
    268

Publication Year

  • 2004
    268