The Experts below are selected from a list of 303 Experts worldwide ranked by ideXlab platform
Juan A. Vallés - One of the best experts on this subject based on the ideXlab platform.
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Ring-Type Erbium-Doped Antiresonant Reflecting Optical Waveguide Amplifier Analysis and Design
IEEE Photonics Technology Letters, 2018Co-Authors: David Benedicto, Juan A. VallésAbstract:Erbium-doped antiresonant reflecting optical wave- guides (ARROWs) allow combining wavelength selective guiding due to their attractive spectral versatility with an active operation. In this letter, the analysis and design of a Ring-type erbium-doped ARROW amplifier is presented. The influence of the involved passive and active parameters (Ring thickness and Diameter, refractive index variation, pump and signal wavelengths, Er3+-ion concentration, and input pump power) on the spectral response of the structure and the optical power propagation losses and on the amplifier performance is numerically analysed. The opposite influence of the Ring Diameter on the optical power confinement and on the pump power density causes the existence of a Diameter value that maximizes the amplifier net gain. For a cladding refractive index of 1.4 and moderate index variations, $\Delta n = 0.2 -0.4$ , the optimum Ring Diameter is in the range of 20 $\mu \text{m}$ . To compensate signal confinement losses (a few dB/cm), high erbium concentrations ( $\sim 1\times 10^{26}$ ion/m3) are required.
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Ring-Type Erbium-Doped Antiresonant Reflecting Optical Waveguide Amplifier Analysis and Design
IEEE Photonics Technology Letters, 2018Co-Authors: David Benedicto, Juan A. VallésAbstract:Erbium-doped antiresonant reflecting optical waveguides (ARROWs) allow combining wavelength selective guiding due to their attractive spectral versatility with an active operation. In this letter, the analysis and design of a Ring-type erbiumdoped ARROW amplifier is presented. The influence of the involved passive and active parameters (Ring thickness and Diameter, refractive index variation, pump and signal wavelengths, Er3+-ion concentration, and input pump power) on the spectral response of the structure and the optical power propagation losses and on the amplifier performance is numerically analysed. The opposite influence of the Ring Diameter on the optical power confinement and on the pump power density causes the existence of a Diameter value that maximizes the amplifier net gain. For a cladding refractive index of 1.4 and moderate index variations, Δn = 0.2 - 0.4, the optimum Ring Diameter is in the range of 20 μm. To compensate signal confinement losses (a few dB/cm), high erbium concentrations (~1 × 1026 ion/m3) are required.
David Benedicto - One of the best experts on this subject based on the ideXlab platform.
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Ring-Type Erbium-Doped Antiresonant Reflecting Optical Waveguide Amplifier Analysis and Design
IEEE Photonics Technology Letters, 2018Co-Authors: David Benedicto, Juan A. VallésAbstract:Erbium-doped antiresonant reflecting optical wave- guides (ARROWs) allow combining wavelength selective guiding due to their attractive spectral versatility with an active operation. In this letter, the analysis and design of a Ring-type erbium-doped ARROW amplifier is presented. The influence of the involved passive and active parameters (Ring thickness and Diameter, refractive index variation, pump and signal wavelengths, Er3+-ion concentration, and input pump power) on the spectral response of the structure and the optical power propagation losses and on the amplifier performance is numerically analysed. The opposite influence of the Ring Diameter on the optical power confinement and on the pump power density causes the existence of a Diameter value that maximizes the amplifier net gain. For a cladding refractive index of 1.4 and moderate index variations, $\Delta n = 0.2 -0.4$ , the optimum Ring Diameter is in the range of 20 $\mu \text{m}$ . To compensate signal confinement losses (a few dB/cm), high erbium concentrations ( $\sim 1\times 10^{26}$ ion/m3) are required.
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Ring-Type Erbium-Doped Antiresonant Reflecting Optical Waveguide Amplifier Analysis and Design
IEEE Photonics Technology Letters, 2018Co-Authors: David Benedicto, Juan A. VallésAbstract:Erbium-doped antiresonant reflecting optical waveguides (ARROWs) allow combining wavelength selective guiding due to their attractive spectral versatility with an active operation. In this letter, the analysis and design of a Ring-type erbiumdoped ARROW amplifier is presented. The influence of the involved passive and active parameters (Ring thickness and Diameter, refractive index variation, pump and signal wavelengths, Er3+-ion concentration, and input pump power) on the spectral response of the structure and the optical power propagation losses and on the amplifier performance is numerically analysed. The opposite influence of the Ring Diameter on the optical power confinement and on the pump power density causes the existence of a Diameter value that maximizes the amplifier net gain. For a cladding refractive index of 1.4 and moderate index variations, Δn = 0.2 - 0.4, the optimum Ring Diameter is in the range of 20 μm. To compensate signal confinement losses (a few dB/cm), high erbium concentrations (~1 × 1026 ion/m3) are required.
Wai-hoi Wong - One of the best experts on this subject based on the ideXlab platform.
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Comparison of a GATE Monte Carlo simulation predictions to the performance of a high-resolution LYSO based dedicated animal PET camera
2011 IEEE Nuclear Science Symposium Conference Record, 2011Co-Authors: Hossain Baghaei, Yuxuan Zhang, Hongdi Li, Rocio A. Ramirez, Chao Wang, Shaohui An, Wai-hoi WongAbstract:A Monte Carlo simulation of the performance of a high-sensitivity and high-resolution small animal positron emission tomography (PET) scanner with a large axial field-of-view (AFOV) is presented and compared to the measured data. The simulated camera is based on the photomultiplier-quadrant-shaRing (PQS) concept and composed of 180 blocks of 13×13 lutetium-yttrium oxyorthosilicate (LYSO) crystals with an average crystal size of 1.24 mm transaxially, 1.4 mm axially, and 9.5 mm radially. The camera has 78 detector Rings with an 11.6 cm AFOV and a Ring Diameter of 16.6 cm. For the simulation, we used the Geant4 Application for Tomographic Emission (GATE) simulation package. We first validated GATE by compaRing its predictions for spatial resolution, absolute sensitivity, and count rate with measured data obtained using an existing bismuth germanate (BGO) based dedicated animal PET scanner that had a similar AFOV and Ring Diameter and was also based on the PQS technique. Simulated and experimental images of the Data Spectrum Micro Deluxe phantom were also compared.
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GATE Monte Carlo Simulation of a High-Sensitivity and High-Resolution LSO-Based Small Animal PET Camera
IEEE Transactions on Nuclear Science, 2007Co-Authors: Hossain Baghaei, Yuxuan Zhang, Hongdi Li, Rocio A. Ramirez, Yu Wang, Wai-hoi WongAbstract:In this paper, we describe a Monte Carlo simulation of the performance of a high-sensitivity and high-resolution small animal positron emission tomography (PET) scanner with a large axial fleld-of-view (AFOV). The simulated camera is based on the photomultiplier-quadrant-shaRing (PQS) concept and composed of 180 blocks of 14 times 14 lutetium oxyorthosilicate (LSO) crystals each measuRing 1.16 mm transaxially, 1.27 mm transaxially, and 9.4 mm radially. The camera has 84 detector Rings with an 11.6 cm AFOV and a Ring Diameter of 16.6 cm. For the simulation, we used the Geant4 Application for Tomographic Emission (GATE) simulation package. We validated GATE by compaRing its predictions for spatial resolution, absolute sensitivity, and count rate with measured data obtained using an existing bismuth germanate (BGO) based dedicated animal PET scanner that had a similar AFOV and Ring Diameter and was based on the PQS technique. Simulated and experimental images of the Data Spectrum Micro Deluxe phantom were also compared. The simulation data suggested that new LSO-based scanner could have reconstructed radial (tangential) spatial resolutions of 1.14 mm (1.14 mm), 1.31 mm (1.32 mm), 1.54 mm (1.52 mm), 2.01 mm (1.8 mm), and 2.4 mm (2.1 mm) at the center and 1 cm, 2 cm, 3 cm, and 4 cm off center, respectively. The simulation data also suggested that 1.2-mm hot rods in the Micro Deluxe phantom will be distinguishable. Simulation predicted an absolute sensitivity of about 7.3% for a point source at the center of the camera assuming an energy window of 300 keV to 750 keV, a coincidence time window of 8 ns, and a system dead time of 60 ns.
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A GATE Monte Carlo Simulation of the Performance of a High-Sensitivity and High-Resolution LSO Based Small Animal PET Camera
2006 IEEE Nuclear Science Symposium Conference Record, 2006Co-Authors: Hossain Baghaei, Yuxuan Zhang, Hongdi Li, Yu Wang, Rocio Ramirez, Wai-hoi WongAbstract:A Monte Carlo simulation of the performance of a high-sensitivity and high-resolution small animal PET scanner with large axial field-of-view (AFOV) is presented. The simulated camera is based on the photomultiplier-quadrant-shaRing technique and composed of 180 blocks of 14 times 14 LSO crystals (each crystal is 1.16 times 1.27 times 10 mm3). The designed camera consists of 84 detector Rings with an AFOV of 11.6 cm and Ring Diameter of 16.6 cm. For simulation, we used GATE (Geant4 Application for Tomographic Emission) simulation package. GATE is a GEANT4 based software toolkit for realistic simulation of PET and SPECT systems. In this study, we first validated GATE by compaRing its prediction for spatial resolution, absolute sensitivity, NEC, and images of the Data Spectrum Micro Deluxe phantom with the measured data using an existing BGO small animal PET scanner which is also based on the photomultiplier-quadrant-shaRing technique and has similar AFOV and Ring Diameter. Spatial resolution simulation was done for point sources located at the center of the camera and also off the center. Simulation data suggest that new LSO scanner could have a reconstructed radial (tangential) spatial resolution of 1.14 (1.14) mm, 1.31 (1.32) mm, 1.54 (1.52) mm, 2.01 (1.8) mm at the center, and 1 cm, 2 cm and 3 cm off the center, respectively. It predicts that 1.2 mm hot rod inserts in the Micro Deluxe phantom will be distinguishable. Simulation predicts an absolute sensitivity of about 6.
Hossain Baghaei - One of the best experts on this subject based on the ideXlab platform.
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Comparison of a GATE Monte Carlo simulation predictions to the performance of a high-resolution LYSO based dedicated animal PET camera
2011 IEEE Nuclear Science Symposium Conference Record, 2011Co-Authors: Hossain Baghaei, Yuxuan Zhang, Hongdi Li, Rocio A. Ramirez, Chao Wang, Shaohui An, Wai-hoi WongAbstract:A Monte Carlo simulation of the performance of a high-sensitivity and high-resolution small animal positron emission tomography (PET) scanner with a large axial field-of-view (AFOV) is presented and compared to the measured data. The simulated camera is based on the photomultiplier-quadrant-shaRing (PQS) concept and composed of 180 blocks of 13×13 lutetium-yttrium oxyorthosilicate (LYSO) crystals with an average crystal size of 1.24 mm transaxially, 1.4 mm axially, and 9.5 mm radially. The camera has 78 detector Rings with an 11.6 cm AFOV and a Ring Diameter of 16.6 cm. For the simulation, we used the Geant4 Application for Tomographic Emission (GATE) simulation package. We first validated GATE by compaRing its predictions for spatial resolution, absolute sensitivity, and count rate with measured data obtained using an existing bismuth germanate (BGO) based dedicated animal PET scanner that had a similar AFOV and Ring Diameter and was also based on the PQS technique. Simulated and experimental images of the Data Spectrum Micro Deluxe phantom were also compared.
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GATE Monte Carlo Simulation of a High-Sensitivity and High-Resolution LSO-Based Small Animal PET Camera
IEEE Transactions on Nuclear Science, 2007Co-Authors: Hossain Baghaei, Yuxuan Zhang, Hongdi Li, Rocio A. Ramirez, Yu Wang, Wai-hoi WongAbstract:In this paper, we describe a Monte Carlo simulation of the performance of a high-sensitivity and high-resolution small animal positron emission tomography (PET) scanner with a large axial fleld-of-view (AFOV). The simulated camera is based on the photomultiplier-quadrant-shaRing (PQS) concept and composed of 180 blocks of 14 times 14 lutetium oxyorthosilicate (LSO) crystals each measuRing 1.16 mm transaxially, 1.27 mm transaxially, and 9.4 mm radially. The camera has 84 detector Rings with an 11.6 cm AFOV and a Ring Diameter of 16.6 cm. For the simulation, we used the Geant4 Application for Tomographic Emission (GATE) simulation package. We validated GATE by compaRing its predictions for spatial resolution, absolute sensitivity, and count rate with measured data obtained using an existing bismuth germanate (BGO) based dedicated animal PET scanner that had a similar AFOV and Ring Diameter and was based on the PQS technique. Simulated and experimental images of the Data Spectrum Micro Deluxe phantom were also compared. The simulation data suggested that new LSO-based scanner could have reconstructed radial (tangential) spatial resolutions of 1.14 mm (1.14 mm), 1.31 mm (1.32 mm), 1.54 mm (1.52 mm), 2.01 mm (1.8 mm), and 2.4 mm (2.1 mm) at the center and 1 cm, 2 cm, 3 cm, and 4 cm off center, respectively. The simulation data also suggested that 1.2-mm hot rods in the Micro Deluxe phantom will be distinguishable. Simulation predicted an absolute sensitivity of about 7.3% for a point source at the center of the camera assuming an energy window of 300 keV to 750 keV, a coincidence time window of 8 ns, and a system dead time of 60 ns.
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A GATE Monte Carlo Simulation of the Performance of a High-Sensitivity and High-Resolution LSO Based Small Animal PET Camera
2006 IEEE Nuclear Science Symposium Conference Record, 2006Co-Authors: Hossain Baghaei, Yuxuan Zhang, Hongdi Li, Yu Wang, Rocio Ramirez, Wai-hoi WongAbstract:A Monte Carlo simulation of the performance of a high-sensitivity and high-resolution small animal PET scanner with large axial field-of-view (AFOV) is presented. The simulated camera is based on the photomultiplier-quadrant-shaRing technique and composed of 180 blocks of 14 times 14 LSO crystals (each crystal is 1.16 times 1.27 times 10 mm3). The designed camera consists of 84 detector Rings with an AFOV of 11.6 cm and Ring Diameter of 16.6 cm. For simulation, we used GATE (Geant4 Application for Tomographic Emission) simulation package. GATE is a GEANT4 based software toolkit for realistic simulation of PET and SPECT systems. In this study, we first validated GATE by compaRing its prediction for spatial resolution, absolute sensitivity, NEC, and images of the Data Spectrum Micro Deluxe phantom with the measured data using an existing BGO small animal PET scanner which is also based on the photomultiplier-quadrant-shaRing technique and has similar AFOV and Ring Diameter. Spatial resolution simulation was done for point sources located at the center of the camera and also off the center. Simulation data suggest that new LSO scanner could have a reconstructed radial (tangential) spatial resolution of 1.14 (1.14) mm, 1.31 (1.32) mm, 1.54 (1.52) mm, 2.01 (1.8) mm at the center, and 1 cm, 2 cm and 3 cm off the center, respectively. It predicts that 1.2 mm hot rod inserts in the Micro Deluxe phantom will be distinguishable. Simulation predicts an absolute sensitivity of about 6.
Loubna El Melhaoui - One of the best experts on this subject based on the ideXlab platform.
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High Q-factor microRings using slightly etched rib waveguides
Journal of Lightwave Technology, 2009Co-Authors: Sylvain Maine, Daniel Pascal, Régis Orobtchouk, Bing Han, Delphine Marris-morini, Laurent Vivien, S Laval, Taha Benyattou, Eric Cassan, Loubna El MelhaouiAbstract:The paper reports the design, fabrication and characterization of\nsilicon-on-insulator (SOI) microRing resonators using shallow etched rib\nwaveguides. The variation of the-factor of microRing resonators as a\nfunction of the Ring Diameter and coupling gap between the input\nwaveguide and the Ring is studied. Such structures are fabricated using\ne-beam lithography and reactive ion etching steps. Propagation loss of\nshallow etching rib waveguide has been evaluated to 0.8 dB/cm for\nwavelengths around 1550 nm. With a Ring Diameter of 100 mu m and a\ncoupling gap of 450 nm, the measured Q-factor is 35300. These results\nare matched by 3-D numerical optical modeling.
