The Experts below are selected from a list of 38952 Experts worldwide ranked by ideXlab platform
Guilhem Gallot - One of the best experts on this subject based on the ideXlab platform.
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Terahertz achromatic quarter-Wave Plate
Optics letters, 2006Co-Authors: Jean-baptiste Masson, Guilhem GallotAbstract:Phase retarders usually present a strong frequency dependence. We discuss the design and characterization of a terahertz achromatic quarter-Wave Plate. This Wave Plate is made from six birefringent quartz Plates precisely designed and stacked together. Phase retardation has been measured over the whole terahertz range by terahertz polarimetry. This achromatic Wave Plate demonstrates a huge frequency bandwidth (numax/numin≈7), and therefore can be applied to terahertz time domain spectroscopy and polarimetry.
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Terahertz achromatic quarter-Wave Plate
Optics Letters, 2006Co-Authors: Jean-baptiste Masson, Guilhem GallotAbstract:Phase retardera usually present a strong frequency dependence. We discuss the design and characterization of a terahertz achromatic quarter-Wave Plate. This Wave Plate is made from six birefringent quartz Plates precisely designed and stacked together. Phase retardation has been measured over the whole terahertz range by terahertz polarimetry. This achromatic Wave Plate demonstrates a huge frequency bandwidth (?max/?min ˜ 7), and therefore can be applied to terahertz time domain spectroscopy and polarimetry. Cop. 2006 Optical Society of America.
J.p. Hughes - One of the best experts on this subject based on the ideXlab platform.
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a model for liquid film flow and separation in a Wave Plate mist eliminator
Chemical Engineering Research & Design, 2005Co-Authors: P W James, Joseph Azzopardi, J.p. HughesAbstract:Wave-Plate mist eliminators operate on the basis that liquid droplets impact on the Plates, accumulate and form thin films which drain away to remove the liquid. However, the effect of the gas flow on the deposited films can be a factor limiting the operational efficiency of the equipment. In this paper numerical simulations of the motion, and subsequent deposition, of droplets on Wave-Plate mist eliminator surfaces are carried out and a model for the generation and flow of the liquid film that forms is presented. Two existing models for film separation from a surface are coupled with the predictions of film thickness to provide a method of determining whether, under a given liquid loading, re-entrainment takes place.
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the role of drainage channels in the performance of Wave Plate mist eliminators
Chemical Engineering Research & Design, 2003Co-Authors: P W James, Barry J. Azzopardi, J.p. HughesAbstract:Numerical simulation of the performance of an idealized Wave-Plate mist eliminator is used to assess the influence of drainage channels in the mist eliminator passages. The effect of the drainage channels on the primary gas flow and on the evolution of the liquid droplet distribution is calculated for a range of gas speeds, Wave-Plate spacing, channel sizes and inlet droplet size distributions. The ability of drainage channels to increase the droplet collection efficiency is confirmed and several features of the flow are predicted which have implications for the design of Wave-Plate mist eliminators.
Minghui Hong - One of the best experts on this subject based on the ideXlab platform.
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switchable ultrathin quarter Wave Plate in terahertz using active phase change metasurface
Scientific Reports, 2015Co-Authors: Dacheng Wang, Lingchao Zhang, Muhammad Qasim Mehmood, Yandong Gong, Amar Srivastava, L K Jian, T Venkatesan, Chengwei Qiu, Minghui HongAbstract:Metamaterials open up various exotic means to control electromagnetic Waves and among them polarization manipulations with metamaterials have attracted intense attention. As of today, static responses of resonators in metamaterials lead to a narrow-band and single-function operation. Extension of the working frequency relies on multilayer metamaterials or different unit cells, which hinder the development of ultra-compact optical systems. In this work, we demonstrate a switchable ultrathin terahertz quarter-Wave Plate by hybridizing a phase change material, vanadium dioxide (VO2), with a metasurface. Before the phase transition, VO2 behaves as a semiconductor and the metasurface operates as a quarter-Wave Plate at 0.468 THz. After the transition to metal phase, the quarter-Wave Plate operates at 0.502 THz. At the corresponding operating frequencies, the metasurface converts a linearly polarized light into a circularly polarized light. This work reveals the feasibility to realize tunable/active and extremely low-profile polarization manipulation devices in the terahertz regime through the incorporation of such phase-change metasurfaces, enabling novel applications of ultrathin terahertz meta-devices.
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an ultrathin terahertz quarter Wave Plate using planar babinet inverted metasurface
Optics Express, 2015Co-Authors: Dacheng Wang, Yandong Gong, Chengwei Qiu, Minghui HongAbstract:Metamaterials promise an exotic approach to artificially manipulate the polarization state of electromagnetic Waves and boost the design of polarimetric devices for sensitive detection, imaging and wireless communication. Here, we present the design and experimental demonstration of an ultrathin (0.29λ) terahertz quarter-Wave Plate based on planar babinet-inverted metasurface. The quarter-Wave Plate consisting of arrays of asymmetric cross apertures reveals a high transmission of 0.545 with 90 degrees phase delay at 0.870 THz. The calculated ellipticity indicates a high degree of polarization conversion from linear to circular polarization. With respect to different incident polarization angles, left-handed circular polarized light, right-handed circular polarized light and elliptically polarized light can be created by this novel design. An analytical model is applied to describe transmitted amplitude, phase delay and ellipticitiy, which are in good agreement with the measured and simulated results. The planar babinet-inverted metasurface with the analytical model opens up avenues for new functional terahertz devices design.
Dacheng Wang - One of the best experts on this subject based on the ideXlab platform.
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switchable ultrathin quarter Wave Plate in terahertz using active phase change metasurface
Scientific Reports, 2015Co-Authors: Dacheng Wang, Lingchao Zhang, Muhammad Qasim Mehmood, Yandong Gong, Amar Srivastava, L K Jian, T Venkatesan, Chengwei Qiu, Minghui HongAbstract:Metamaterials open up various exotic means to control electromagnetic Waves and among them polarization manipulations with metamaterials have attracted intense attention. As of today, static responses of resonators in metamaterials lead to a narrow-band and single-function operation. Extension of the working frequency relies on multilayer metamaterials or different unit cells, which hinder the development of ultra-compact optical systems. In this work, we demonstrate a switchable ultrathin terahertz quarter-Wave Plate by hybridizing a phase change material, vanadium dioxide (VO2), with a metasurface. Before the phase transition, VO2 behaves as a semiconductor and the metasurface operates as a quarter-Wave Plate at 0.468 THz. After the transition to metal phase, the quarter-Wave Plate operates at 0.502 THz. At the corresponding operating frequencies, the metasurface converts a linearly polarized light into a circularly polarized light. This work reveals the feasibility to realize tunable/active and extremely low-profile polarization manipulation devices in the terahertz regime through the incorporation of such phase-change metasurfaces, enabling novel applications of ultrathin terahertz meta-devices.
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an ultrathin terahertz quarter Wave Plate using planar babinet inverted metasurface
Optics Express, 2015Co-Authors: Dacheng Wang, Yandong Gong, Chengwei Qiu, Minghui HongAbstract:Metamaterials promise an exotic approach to artificially manipulate the polarization state of electromagnetic Waves and boost the design of polarimetric devices for sensitive detection, imaging and wireless communication. Here, we present the design and experimental demonstration of an ultrathin (0.29λ) terahertz quarter-Wave Plate based on planar babinet-inverted metasurface. The quarter-Wave Plate consisting of arrays of asymmetric cross apertures reveals a high transmission of 0.545 with 90 degrees phase delay at 0.870 THz. The calculated ellipticity indicates a high degree of polarization conversion from linear to circular polarization. With respect to different incident polarization angles, left-handed circular polarized light, right-handed circular polarized light and elliptically polarized light can be created by this novel design. An analytical model is applied to describe transmitted amplitude, phase delay and ellipticitiy, which are in good agreement with the measured and simulated results. The planar babinet-inverted metasurface with the analytical model opens up avenues for new functional terahertz devices design.
Jean-baptiste Masson - One of the best experts on this subject based on the ideXlab platform.
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Terahertz achromatic quarter-Wave Plate
Optics letters, 2006Co-Authors: Jean-baptiste Masson, Guilhem GallotAbstract:Phase retarders usually present a strong frequency dependence. We discuss the design and characterization of a terahertz achromatic quarter-Wave Plate. This Wave Plate is made from six birefringent quartz Plates precisely designed and stacked together. Phase retardation has been measured over the whole terahertz range by terahertz polarimetry. This achromatic Wave Plate demonstrates a huge frequency bandwidth (numax/numin≈7), and therefore can be applied to terahertz time domain spectroscopy and polarimetry.
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Terahertz achromatic quarter-Wave Plate
Optics Letters, 2006Co-Authors: Jean-baptiste Masson, Guilhem GallotAbstract:Phase retardera usually present a strong frequency dependence. We discuss the design and characterization of a terahertz achromatic quarter-Wave Plate. This Wave Plate is made from six birefringent quartz Plates precisely designed and stacked together. Phase retardation has been measured over the whole terahertz range by terahertz polarimetry. This achromatic Wave Plate demonstrates a huge frequency bandwidth (?max/?min ˜ 7), and therefore can be applied to terahertz time domain spectroscopy and polarimetry. Cop. 2006 Optical Society of America.
