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155,423 Works

Optofluidic waveguides for reconfigurable photonic systems

Aram J. Chung & David Erickson
We report the development of two liquid waveguide based photonic elements for use in reconfigurable photonic systems. This work demonstrates the ability to couple light from a conventional optical fiber to an adaptable liquid-core/liquid-cladding waveguide and back again to an optical fiber(s) enabling us to take advantage of both liquid- and solid-state photonic modalities. We demonstrate and characterize the use of this fiber-in and fiber-out system as either an optical switch or signal attenuator. Microscale...

Optofluidic waveguides for reconfigurable photonic systems

Aram J. Chung & David Erickson
We report the development of two liquid waveguide based photonic elements for use in reconfigurable photonic systems. This work demonstrates the ability to couple light from a conventional optical fiber to an adaptable liquid-core/liquid-cladding waveguide and back again to an optical fiber(s) enabling us to take advantage of both liquid- and solid-state photonic modalities. We demonstrate and characterize the use of this fiber-in and fiber-out system as either an optical switch or signal attenuator. Microscale...

Megahertz OCT for ultrawide-field retinal imaging with a 1050nm Fourier domain mode-locked laser

Thomas Klein, Wolfgang Wieser, Christoph M. Eigenwillig, Benjamin R. Biedermann & Robert Huber
We demonstrate ultrahigh speed swept source retinal OCT imaging using a Fourier domain mode locked (FDML) laser. The laser uses a combination of a semiconductor optical amplifier and an ytterbium doped fiber amplifier to provide more than 50mW output power. The 1050nm FDML laser uses standard telecom fiber for the km long delay line instead of two orders of magnitude more expensive real single mode fiber. We investigate the influence of this “oligo-mode” fiber on...

Megahertz OCT for ultrawide-field retinal imaging with a 1050nm Fourier domain mode-locked laser

Thomas Klein, Wolfgang Wieser, Christoph M. Eigenwillig, Benjamin R. Biedermann & Robert Huber
We demonstrate ultrahigh speed swept source retinal OCT imaging using a Fourier domain mode locked (FDML) laser. The laser uses a combination of a semiconductor optical amplifier and an ytterbium doped fiber amplifier to provide more than 50mW output power. The 1050nm FDML laser uses standard telecom fiber for the km long delay line instead of two orders of magnitude more expensive real single mode fiber. We investigate the influence of this “oligo-mode” fiber on...

Four-dimensional X-ray phase tomography with Talbot interferometry and white synchrotron radiation: dynamic observation of a living worm

Atsushi Momose, Wataru Yashiro, Sébastien Harasse & Hiroaki Kuwabara
X-ray Talbot interferometry is attractive as a method for X-ray phase imaging and phase tomography for objects that weakly absorb X-rays. Because X-ray Talbot interferometry has the advantage that X-rays of a broad energy bandwidth can be used, high-speed X-ray phase imaging is possible with white synchrotron radiation. In this paper, we demonstrate time-resolved three-dimensional observation with X-ray Talbot interferometry (namely, four-dimensional X-ray phase tomography). Differential phase images, from which a phase tomogram was reconstructed,...

Four-dimensional X-ray phase tomography with Talbot interferometry and white synchrotron radiation: dynamic observation of a living worm

Atsushi Momose, Wataru Yashiro, Sébastien Harasse & Hiroaki Kuwabara
X-ray Talbot interferometry is attractive as a method for X-ray phase imaging and phase tomography for objects that weakly absorb X-rays. Because X-ray Talbot interferometry has the advantage that X-rays of a broad energy bandwidth can be used, high-speed X-ray phase imaging is possible with white synchrotron radiation. In this paper, we demonstrate time-resolved three-dimensional observation with X-ray Talbot interferometry (namely, four-dimensional X-ray phase tomography). Differential phase images, from which a phase tomogram was reconstructed,...

Tracking integration in concentrating photovoltaics using laterally moving optics

Fabian Duerr, Youri Meuret & Hugo Thienpont
In this work the concept of tracking-integrated concentrating photovoltaics is studied and its capabilities are quantitatively analyzed. The design strategy desists from ideal concentration performance to reduce the external mechanical solar tracking effort in favor of a compact installation, possibly resulting in lower overall cost. The proposed optical design is based on an extended Simultaneous Multiple Surface (SMS) algorithm and uses two laterally moving plano-convex lenses to achieve high concentration over a wide angular range...

Tracking integration in concentrating photovoltaics using laterally moving optics

Fabian Duerr, Youri Meuret & Hugo Thienpont
In this work the concept of tracking-integrated concentrating photovoltaics is studied and its capabilities are quantitatively analyzed. The design strategy desists from ideal concentration performance to reduce the external mechanical solar tracking effort in favor of a compact installation, possibly resulting in lower overall cost. The proposed optical design is based on an extended Simultaneous Multiple Surface (SMS) algorithm and uses two laterally moving plano-convex lenses to achieve high concentration over a wide angular range...

Cell-based hardware architecture for full-parallel generation algorithm of digital holograms

Young-Ho Seo, Hyun-Jun Choi, Ji-Sang Yoo & Dong-Wook Kim
This paper proposes a new hardware architecture to speed-up the digital hologram calculation by parallel computation. To realize it, we modify the computer-generated hologram (CGH) equation and propose a cell-based very large scale integrated circuit architecture. We induce a new equation to calculate the horizontal or vertical hologram pixel values in parallel, after finding the calculation regularity in the horizontal or vertical direction from the basic CGH equation. We also propose the architecture of the...

3D shape measurement technique for multiple rapidly moving objects

Yajun Wang, Song Zhang & James H. Oliver
Recently proposed binary defocusing techniques have led to ultrafast speed 3D shape measurement, but they are generally limited to measurement of a single object at a time. Introducing additional gray coded patterns for point-by-point phase unwrapping could permit simultaneous multiple-object measurement. However, when the objects are moving rapidly, the displacement between the first captured pattern and the last can be significant, and pose challenges related to the precisely designed gray codes. This paper presents a...

Cell-based hardware architecture for full-parallel generation algorithm of digital holograms

Young-Ho Seo, Hyun-Jun Choi, Ji-Sang Yoo & Dong-Wook Kim
This paper proposes a new hardware architecture to speed-up the digital hologram calculation by parallel computation. To realize it, we modify the computer-generated hologram (CGH) equation and propose a cell-based very large scale integrated circuit architecture. We induce a new equation to calculate the horizontal or vertical hologram pixel values in parallel, after finding the calculation regularity in the horizontal or vertical direction from the basic CGH equation. We also propose the architecture of the...

Enhancement of the optical transmission by mixing the metallic and dielectric nanoparticles atop the silicon substrate

Yung-Ming Yeh, Yu-Sheng Wang & Jia-Han Li
We propose a structure with the metallic and dielectric nanoparticles on the surface of the silicon material and study its optical transmission properties. The structure with the radiuses of the silver and silica nanoparticles as 50 nm and 100 nm, respectively, with the gap as 8 nm between silver and silica nanoparticles is found to have the largest optical transmission into the silicon material in our simulations. The largest field intensities are on the bottom...

3D shape measurement technique for multiple rapidly moving objects

Yajun Wang, Song Zhang & James H. Oliver
Recently proposed binary defocusing techniques have led to ultrafast speed 3D shape measurement, but they are generally limited to measurement of a single object at a time. Introducing additional gray coded patterns for point-by-point phase unwrapping could permit simultaneous multiple-object measurement. However, when the objects are moving rapidly, the displacement between the first captured pattern and the last can be significant, and pose challenges related to the precisely designed gray codes. This paper presents a...

Enhancement of the optical transmission by mixing the metallic and dielectric nanoparticles atop the silicon substrate

Yung-Ming Yeh, Yu-Sheng Wang & Jia-Han Li
We propose a structure with the metallic and dielectric nanoparticles on the surface of the silicon material and study its optical transmission properties. The structure with the radiuses of the silver and silica nanoparticles as 50 nm and 100 nm, respectively, with the gap as 8 nm between silver and silica nanoparticles is found to have the largest optical transmission into the silicon material in our simulations. The largest field intensities are on the bottom...

Real-time terahertz near-field microscope

F. Blanchard, A. Doi, T. Tanaka, H. Hirori, H. Tanaka, Y. Kadoya & K. Tanaka
We report a terahertz near-field microscope with a high dynamic range that can capture images of a 370 x 740 μm2 area at 35 frames per second. We achieve high spatial resolution (14 μm corresponding to λ/30 for a center frequency at 0.7 THz) on a large area by combining two novel techniques: terahertz generation by tilted-pulse-front excitation and electro-optic balanced imaging detection using a thin crystal. To demonstrate the microscope capability, we reveal the...

Real-time terahertz near-field microscope

F. Blanchard, A. Doi, T. Tanaka, H. Hirori, H. Tanaka, Y. Kadoya & K. Tanaka
We report a terahertz near-field microscope with a high dynamic range that can capture images of a 370 x 740 μm2 area at 35 frames per second. We achieve high spatial resolution (14 μm corresponding to λ/30 for a center frequency at 0.7 THz) on a large area by combining two novel techniques: terahertz generation by tilted-pulse-front excitation and electro-optic balanced imaging detection using a thin crystal. To demonstrate the microscope capability, we reveal the...

Controlling total spot power from holographic laser by superimposing a binary phase grating

Xiang Liu, Jian Zhang, Yu Gan & Liying Wu
By superimposing a tunable binary phase grating with a conventional computer-generated hologram, the total power of multiple holographic 3D spots can be easily controlled by changing the phase depth of grating with high accuracy to a random power value for real-time optical manipulation without extra power loss. Simulation and experiment results indicate that a resolution of 0.002 can be achieved at a lower time cost for normalized total spot power.

Controlling total spot power from holographic laser by superimposing a binary phase grating

Xiang Liu, Jian Zhang, Yu Gan & Liying Wu
By superimposing a tunable binary phase grating with a conventional computer-generated hologram, the total power of multiple holographic 3D spots can be easily controlled by changing the phase depth of grating with high accuracy to a random power value for real-time optical manipulation without extra power loss. Simulation and experiment results indicate that a resolution of 0.002 can be achieved at a lower time cost for normalized total spot power.

Optically driven Archimedes micro-screws for micropump application

Chih-Lang Lin, Guy Vitrant, Michel Bouriau, Roger Casalegno & Patrice L. Baldeck
Archimedes micro-screws have been fabricated by three-dimensional two-photon polymerization using a Nd:YAG Q-switched microchip laser at 532nm. Due to their small sizes they can be easily manipulated, and made to rotate using low power optical tweezers. Rotation rates up to 40 Hz are obtained with a laser power of 200 mW, i.e. 0.2 Hz/mW. A photo-driven micropump action in a microfluidic channel is demonstrated with a non-optimized flow rate of 6pL/min. The optofluidic properties of...

Optically driven Archimedes micro-screws for micropump application

Chih-Lang Lin, Guy Vitrant, Michel Bouriau, Roger Casalegno & Patrice L. Baldeck
Archimedes micro-screws have been fabricated by three-dimensional two-photon polymerization using a Nd:YAG Q-switched microchip laser at 532nm. Due to their small sizes they can be easily manipulated, and made to rotate using low power optical tweezers. Rotation rates up to 40 Hz are obtained with a laser power of 200 mW, i.e. 0.2 Hz/mW. A photo-driven micropump action in a microfluidic channel is demonstrated with a non-optimized flow rate of 6pL/min. The optofluidic properties of...

Femtosecond laser filament-fringes in fused silica

Zuoqiang Hao, Kamil Stelmaszczyk, Philipp Rohwetter, Walter M. Nakaema & Ludger Woeste
Linear diffraction was used to modulate intensity distribution across the femtosecond laser beam to create quasi regular arrays of filaments in fused silica. A fringe type of filament distributions (filament-fringe) were formed that could be controlled and observed over a distance of several millimeters. The difference of supercontinuum (SC) emission between individual filaments was also observed.

Femtosecond laser filament-fringes in fused silica

Zuoqiang Hao, Kamil Stelmaszczyk, Philipp Rohwetter, Walter M. Nakaema & Ludger Woeste
Linear diffraction was used to modulate intensity distribution across the femtosecond laser beam to create quasi regular arrays of filaments in fused silica. A fringe type of filament distributions (filament-fringe) were formed that could be controlled and observed over a distance of several millimeters. The difference of supercontinuum (SC) emission between individual filaments was also observed.

Fast scanning peripheral wave-front sensor for the human eye

Bart Jaeken, Linda Lundström & Pablo Artal
We designed and built a fast scanning peripheral Hartmann-Shack (HS) wave-front sensor to measure the off-axis wave-front aberrations in the human eye. The new instrument is capable of measuring the optical quality over the central 80° horizontal visual field in 1.8 seconds with an angular resolution of 1°. The subject has an open field of view without any moving elements in the line-of-sight and the head is kept in place by a head-chin rest. The...

Fast scanning peripheral wave-front sensor for the human eye

Bart Jaeken, Linda Lundström & Pablo Artal
We designed and built a fast scanning peripheral Hartmann-Shack (HS) wave-front sensor to measure the off-axis wave-front aberrations in the human eye. The new instrument is capable of measuring the optical quality over the central 80° horizontal visual field in 1.8 seconds with an angular resolution of 1°. The subject has an open field of view without any moving elements in the line-of-sight and the head is kept in place by a head-chin rest. The...

All-optical ultrafast control of beaming through a single sub-wavelength aperture in a metal film

Mohamed A. Swillam, Nir Rotenberg & Henry M. Van Driel
We propose an ultrafast all-optical technique to control and beam the light emerging from a sub-wavelength slit in a planar gold film by exciting a transient grating in the area around the slit. A FDTD model is used to show how excitation of surface plasmon polaritons by the grating governs the beaming process. Both the grating and the beaming effect are shown to decay on a picosecond time-scale. An on-off contrast of 5 dB is...

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  • 2011
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