The Experts below are selected from a list of 315 Experts worldwide ranked by ideXlab platform
Kyo Inoue - One of the best experts on this subject based on the ideXlab platform.
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Differential Phase-Shift Quantum Key Distribution Systems
IEEE Journal of Selected Topics in Quantum Electronics, 2015Co-Authors: Kyo InoueAbstract:Differential Phase-shift (DPS) quantum key distribution (QKD) is a unique QKD protocol that is different from traditional ones, featuring simplicity and practicality. This paper overviews DPS-QKD systems.
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Differential-Phase-shift quantum secret sharing.
Optics express, 2008Co-Authors: Kyo Inoue, Toshimori Honjo, T. Ohashi, T. Kukita, K. Watanebe, S. Hayashi, Hiroki TakesueAbstract:A quantum secret sharing (QSS) protocol based on a Differential-Phase-shift scheme is proposed, which quantum mechanically provides a full secret key to one party and partial keys to two other parties. A weak coherent pulse train is utilized instead of individual photons as in conventional schemes. Compared with previous QSS protocols, the present one features a simple setup, is suitable for fiber transmission, and offers the possibility for a high key creation rate. An experiment is also carried out to demonstrate the operation.
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Differential Phase shift quantum key distribution using coherent light
Physical Review A, 2003Co-Authors: Kyo Inoue, Edo Waks, Yoshihisa YamamotoAbstract:Differential-Phase-shift quantum key distribution based on two nonorthogonal states is described. A weak coherent pulse train is sent from Alice to Bob, in which the Phase of each pulse is randomly modulated by {l_brace}0,{pi}{r_brace}. Bob measures the Differential Phase by a one-bit delay circuit. The system has a simple configuration without the need for an interferometer and a bright reference pulse in Alice's site, unlike the conventional QKD system based on two nonorthogonal states, and has an advantage of improved communication efficiency. The principle of the operation is successfully demonstrated in experiments.
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Differential Phase shift quantum key distribution
Physical Review Letters, 2002Co-Authors: Kyo Inoue, Edo Waks, Yoshihisa YamamotoAbstract:A novel quantum cryptography scheme is proposed, in which a single photon is prepared in a linear superposition state of three basis kets. A photon split to three pulses is sent from Alice to Bob, where the Phase difference between sequential two pulses carries bit information. Bob measures the Phase difference by passive Differential Phase detection. This scheme is suitable for fiber transmission systems and offers a key creation efficiency higher than conventional fiber-based BB84.
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Differential-Phase-shift quantum key distribution
2006 Digest of the LEOS Summer Topical Meetings, 1Co-Authors: Kyo Inoue, Hiroki Takesue, Toshimori HonjoAbstract:A novel type of quantum key distribution (QKD) protocol called Differential-Phase-shift (DPS) QKD is described. It utilizes a weak coherent pulse train instead of individual photons as in conventional QKD.
Chien Chou - One of the best experts on this subject based on the ideXlab platform.
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Differential Phase decoder in a polarized optical heterodyne interferometer
Journal of the Optical Society of America. A Optics image science and vision, 2008Co-Authors: Chien Chou, Hui-kang Teng, Chien-chung TsaiAbstract:A Differential-Phase decoder (DPD) together with a polarization common-path optical heterodyne interferometer is set up. Based on this interferometric configuration and a novel balanced-detector scheme, the performance of the quantum-noise-limited Differential-Phase decoder is demonstrated and analyzed. The minimum-detectable Differential Phase is on the order of 10−7 rad/sqrt Hz when a 2.5 mW He-Ne laser is used. Verified experimentally, the DPD is immune to the common-Phase noise induced by an electro-optic Phase modulator or by thermal disturbance within the interferometer. This signifies that the minimum-detectable Differential Phase can become 10−8 rad/sqrt Hz if a 300 mW continuous wave laser is employed instead.
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Analog Differential-Phase detection in optical coherence reflectometer
Optics express, 2008Co-Authors: Huan-jang Huang, Tsung-yu Hsieh, Li-dek Chou, Wen-chuan Kuo, Chien ChouAbstract:A novel Differential-Phase optical coherence reflectometer (DP-OCR) was proposed using a low-coherence source, integrating it with an analog Differential-Phase decoding method. In the experiment, the DP-OCR performed a localized surface profile measurement of an optical grating (1200 lp/mm) and demonstrated its ability to measure the translation speed of a tilted mirror. Experimentally, the resolution of the axial displacement of proposed DP-OCR at 185 pm was demonstrated.
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Differential-Phase surface plasmon resonance biosensor.
Analytical chemistry, 2008Co-Authors: Ying-feng Chang, Chien ChouAbstract:In this paper, a novel Differential-Phase-sensitive surface plasmon resonance biosensor (DP-SPRB) is proposed and developed, in which a two-frequency laser is integrated with a Differential amplifier in order to analytically convert the Phase modulation into amplitude modulation. With the use of the conventional envelope detection technique, the Differential Phase is precisely decoded in real time in terms of the demodulated amplitude. In order to verify high detection sensitivity of the DP-SPRB, a sucrose-water solution and glycerin-water solution at low concentrations were both tested, and the experimental results confirm that the detection sensitivity on wt % concentration of the sucrose solution is 0.00001%. Moreover, the real-time monitoring mouse IgG/antimouse IgG interaction shows the minimum concentration of mouse IgG to be at 10 fg/mL. To our knowledge, this is the highest sensitivity ever measured by a surface plasmon resonance biosensor. However, because of the limited dynamic range of DP-SPRB, it can only apply to biomolecule interactions at extremely low concentration.
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Differential-Phase optical coherence reflectometer for surface profile measurement
Optical Coherence Tomography and Coherence Techniques III, 2007Co-Authors: Huan-jang Huang, Wen-chuan Kuo, Sheng-yi Chang, Chien ChouAbstract:We developed a novel Differential-Phase optical coherence reflectometer (DP-OCR) by using a low-coherence light source and integrated with Differential Phase detection technique on surface profile measurement. In this setup, 2A on detection of axial displacement was demonstrated. Thus, a localized surface profile was measured precisely by scanning an optical grating surface in this measurement. Moreover, the requirement on equal amplitude of the reference and signal beams of this novel reflectometer is discussed.
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Linear Birefringence Measurement with a Differential-Phase Optical Heterodyne Polarimeter
Japanese Journal of Applied Physics, 2002Co-Authors: Hui-kang Teng, Chien Chou, Chung-wei Lyu, Chia-nan Chang, Yue-chuan HuangAbstract:To measure the linear birefringence of a quartz crystal, an optical heterodyne ring interferometer associated with a Differential Phase detection technique is proposed. The Differential Phase detection performs a common noise rejection similar to a balanced detector for noise reduction. The Differential Phase detection also plays the role of a Phase modulation to amplitude modulation (AM) converter to decode the Phase difference between two equal amplitude input heterodyne signals with the same carrier frequency. In this study, a quartz Babinet compensator is used as a test sample and the linear birefringence of the quartz can be measured in terms of the magnitude of an AM signal from a Differential amplifier. In comparison with conventional methods, a wider dynamic range and better accuracy of the linear birefringence measurement of a crystal in Babinet compensator geometry are realized. From the experimental results, the linear birefringence of quartz with accuracy of 10-5 order is obtained. The error analysis is also presented.
Franz Pfeiffer - One of the best experts on this subject based on the ideXlab platform.
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a theoretical framework for comparing noise characteristics of spectral Differential Phase contrast and spectral Differential Phase contrast x ray imaging
arXiv: Medical Physics, 2019Co-Authors: Korbinian Mechlem, Thorsten Sellerer, Manuel Viermetz, Julia Herzen, Franz PfeifferAbstract:Spectral and grating-based Differential Phase-contrast X-ray imaging are two emerging technologies that offer additional information compared with conventional attenuation-based X-ray imaging. In the case of spectral imaging, energy-resolved measurements allow the generation of material-specific images by exploiting differences in the energy-dependent attenuation. Differential Phase-contrast imaging uses the Phase shift that an X-ray wave exhibits when traversing an object as contrast generation mechanism. Recently, we have investigated the combination of these two imaging techniques (spectral Differential Phase-contrast imaging) and demonstrated potential advantages compared with spectral imaging. In this work, we present a noise analysis framework that allows the prediction of (co-) variances and noise power spectra for all three imaging methods. Moreover, the optimum acquisition parameters for a particular imaging task can be determined. We use this framework for a performance comparison of all three imaging methods. The comparison is focused on (projected) electron density images since they can be calculated with all three imaging methods. Our study shows that spectral Differential Phase-contrast imaging enables the calculation of electron density images with strongly reduced noise levels compared with the other two imaging methods for a large range of clinically relevant pixel sizes. In contrast to conventional Differential Phase-contrast imaging, there are no long-range noise correlations for spectral Differential Phase-contrast imaging. This means that excessive low frequency noise can be avoided. We confirm the analytical predictions by numerical simulations.
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Spectral Differential Phase Contrast X-ray Radiography
IEEE Transactions on Medical Imaging, 1Co-Authors: Korbinian Mechlem, Thorsten Sellerer, Manuel Viermetz, Julia Herzen, Franz PfeifferAbstract:We investigate the combination of two emerging X-ray imaging technologies, namely spectral imaging and Differential Phase contrast imaging. By acquiring spatially and temporally registered images with several different X-ray spectra, spectral imaging can exploit differences in the energy-dependent attenuation to generate material selective images. Differential Phase contrast imaging uses an entirely different contrast generation mechanism: The Phase shift that an X-ray wave exhibits when traversing an object. As both methods can determine the (projected) electron density, we propose a novel material decomposition algorithm that uses the spectral and the Phase contrast information simultaneously. Numerical experiments show that the combination of these two imaging techniques benefits from the strengths of the individual methods while the weaknesses are mitigated: Quantitatively accurate basis material images are obtained and the noise level is strongly reduced, compared to conventional spectral X-ray imaging.
Yoshihisa Yamamoto - One of the best experts on this subject based on the ideXlab platform.
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Differential Phase shift quantum key distribution using coherent light
Physical Review A, 2003Co-Authors: Kyo Inoue, Edo Waks, Yoshihisa YamamotoAbstract:Differential-Phase-shift quantum key distribution based on two nonorthogonal states is described. A weak coherent pulse train is sent from Alice to Bob, in which the Phase of each pulse is randomly modulated by {l_brace}0,{pi}{r_brace}. Bob measures the Differential Phase by a one-bit delay circuit. The system has a simple configuration without the need for an interferometer and a bright reference pulse in Alice's site, unlike the conventional QKD system based on two nonorthogonal states, and has an advantage of improved communication efficiency. The principle of the operation is successfully demonstrated in experiments.
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Differential Phase shift quantum key distribution
Physical Review Letters, 2002Co-Authors: Kyo Inoue, Edo Waks, Yoshihisa YamamotoAbstract:A novel quantum cryptography scheme is proposed, in which a single photon is prepared in a linear superposition state of three basis kets. A photon split to three pulses is sent from Alice to Bob, where the Phase difference between sequential two pulses carries bit information. Bob measures the Phase difference by passive Differential Phase detection. This scheme is suitable for fiber transmission systems and offers a key creation efficiency higher than conventional fiber-based BB84.
Korbinian Mechlem - One of the best experts on this subject based on the ideXlab platform.
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a theoretical framework for comparing noise characteristics of spectral Differential Phase contrast and spectral Differential Phase contrast x ray imaging
arXiv: Medical Physics, 2019Co-Authors: Korbinian Mechlem, Thorsten Sellerer, Manuel Viermetz, Julia Herzen, Franz PfeifferAbstract:Spectral and grating-based Differential Phase-contrast X-ray imaging are two emerging technologies that offer additional information compared with conventional attenuation-based X-ray imaging. In the case of spectral imaging, energy-resolved measurements allow the generation of material-specific images by exploiting differences in the energy-dependent attenuation. Differential Phase-contrast imaging uses the Phase shift that an X-ray wave exhibits when traversing an object as contrast generation mechanism. Recently, we have investigated the combination of these two imaging techniques (spectral Differential Phase-contrast imaging) and demonstrated potential advantages compared with spectral imaging. In this work, we present a noise analysis framework that allows the prediction of (co-) variances and noise power spectra for all three imaging methods. Moreover, the optimum acquisition parameters for a particular imaging task can be determined. We use this framework for a performance comparison of all three imaging methods. The comparison is focused on (projected) electron density images since they can be calculated with all three imaging methods. Our study shows that spectral Differential Phase-contrast imaging enables the calculation of electron density images with strongly reduced noise levels compared with the other two imaging methods for a large range of clinically relevant pixel sizes. In contrast to conventional Differential Phase-contrast imaging, there are no long-range noise correlations for spectral Differential Phase-contrast imaging. This means that excessive low frequency noise can be avoided. We confirm the analytical predictions by numerical simulations.
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Spectral Differential Phase Contrast X-ray Radiography
IEEE Transactions on Medical Imaging, 1Co-Authors: Korbinian Mechlem, Thorsten Sellerer, Manuel Viermetz, Julia Herzen, Franz PfeifferAbstract:We investigate the combination of two emerging X-ray imaging technologies, namely spectral imaging and Differential Phase contrast imaging. By acquiring spatially and temporally registered images with several different X-ray spectra, spectral imaging can exploit differences in the energy-dependent attenuation to generate material selective images. Differential Phase contrast imaging uses an entirely different contrast generation mechanism: The Phase shift that an X-ray wave exhibits when traversing an object. As both methods can determine the (projected) electron density, we propose a novel material decomposition algorithm that uses the spectral and the Phase contrast information simultaneously. Numerical experiments show that the combination of these two imaging techniques benefits from the strengths of the individual methods while the weaknesses are mitigated: Quantitatively accurate basis material images are obtained and the noise level is strongly reduced, compared to conventional spectral X-ray imaging.