A new generation algorithm of two-dimensional triple-codeweight asymmetric optical orthogonal codes for optical code division multiple access (OCDMA) networks is proposed. The code cardinality is obtained and the er...
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A new generation algorithm of two-dimensional triple-codeweight asymmetric optical orthogonal codes for optical code division multiple access (OCDMA) networks is proposed. The code cardinality is obtained and the error-probability performance for corresponding OCDMA system is analyzed. The codes with two constraints (i.e., auto- and cross-correlation properties) being unequal are taken into account. On the premise of fixed system resources, the code of the error-probability performance, it is shown cardinality can be significantly improved. By analysis that the codes with different parameters have different performances. Therefore, this type of codes can be applied to support diverse quality of service (QoS) and satisfy the quality requirement of different multimedia or distinct users, and simultaneously make the better use of bandwidth resources in oDtical networks.
We present a cascaded system designed with Er^3+-Doped,Tm^3+-doped and Nd^3+-doped fibers to realize amplified spontaneous emission(ASE)spectra covering 0.4—2.0μ*** system is excited with a pump laser emitting 808 n...
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We present a cascaded system designed with Er^3+-Doped,Tm^3+-doped and Nd^3+-doped fibers to realize amplified spontaneous emission(ASE)spectra covering 0.4—2.0μ*** system is excited with a pump laser emitting 808 nm photons with 500 m W pump *** emission spectra of the cascaded system covering0.4—2.0μm are realized with the Er^3+,Tm^3+and Nd^3+ion doping densities optimized to 8×10^19,2×10^20 and8×10^20 ion/m^3,respectively,and the fiber length optimized to 1 *** methods reveal that the peak ASE power for the cascaded system can reach 20.9 m W.A minimum ASE power of 4.39 m W is *** numerical calculations and analytical techniques,we provide a detailed insight into optimized Er^3+-doped,Tm^3+-doped and Nd^3+-doped fiber lengths and their doping concentrations for ASE power spectra covering 0.4—2.0μ*** believe that the cascaded system can potentially provide significant applications in various optical fields which include but not limited to wavelength-division multiplexing,various opticalcommunications and other salient medical imaging processes.
An incident wave at a temporal interface, created by an abrupt change in system parameters, generates time-refracted and time-reflected waves. We find topological characteristics associated with the temporal interface...
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Recent patents and progress on all-optical binary pattern recognition using the passive correlator and all-optical logic gates have been reviewed. The correlator is relative simpler and easy to be implemented, however...
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Active optical clock,a new conception of atomic clock,has been proposed *** this work,we propose a scheme of active optical clock based on four-level quantum *** final accuracy and stability of two-level quantum syste...
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Active optical clock,a new conception of atomic clock,has been proposed *** this work,we propose a scheme of active optical clock based on four-level quantum *** final accuracy and stability of two-level quantum system are limited by second-order Doppler shift of thermal atomic *** three-level quantum system,they are mainly limited by light shift of pumping laser *** limitations can be avoided effectively by applying the scheme proposed *** atom four-level quantum system,as a typical example,is *** population inversion between 6S 1/2 and 5P 3/2 states can be built up at a time scale of 10-6 *** the mechanism of active optical clock,in which the cavity mode linewidth is much wider than that of the laser gain profile,it can output a laser with quantum-limited linewidth narrower than 1 Hz in *** experimental configuration is designed to realize this active optical clock.
We investigate a framework of the cooperative quantum teleportation (CQT) based on non-maximally entangled state basis (NB) measurements,instead of maximally entangled state basis (MB) *** is implemented with two cons...
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We investigate a framework of the cooperative quantum teleportation (CQT) based on non-maximally entangled state basis (NB) measurements,instead of maximally entangled state basis (MB) *** is implemented with two consecutive conventional (or direct) quantum telportations (DQT),where unknown quantum states can be transmitted in a point-to-point *** security is based on the quantum-mechanical impossibility of local unitary transformations between non-maximally entangled *** shows that the CQT can enhance the successful transmissions by self-correcting the errors introduced in the dual-teleportations.
We propose a theoretical mechanism and new coding strategy to realize extremely accurate manipulations of nonlinear electromagnetic harmonics in ultrawide frequency band based on a time-domain digital coding metasurfa...
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We propose a theoretical mechanism and new coding strategy to realize extremely accurate manipulations of nonlinear electromagnetic harmonics in ultrawide frequency band based on a time-domain digital coding metasurface(TDCM).Using the proposed mechanism and coding strategy,we design and fabricate a millimeter-wave(mmWave) TDCM,which is composed of reprogrammable meta-atoms embedded with positive-intrinsic-negative *** controlling the duty ratios and time delays of the digital coding sequences loaded on a TDCM,experimental results show that both amplitudes and phases of different harmonics can be engineered at will simultaneously and precisely in broad frequency band from 22 to33 GHz,even when the coding states are imperfect,which is in good agreement with theoretical *** on the fabricated high-performance TDCM,we further propose and experimentally realize a large-capacity mmWave wireless communicationsystem,where 256 quadrature amplitude modulation,along with other schemes,is *** new wireless communicationsystem has a much simpler architecture than the currently used mmWave wireless systems,and hence can significantly reduce the hardware *** believe that the proposed method and system architecture can find vast application in future mmWave and terahertz-wave wireless communication and radar systems.
With the increasing popularity of fingerprint identification technology, its security and privacy have been paid much attention. Only the security and privacy of biological information are insured, the biological tech...
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With the increasing popularity of fingerprint identification technology, its security and privacy have been paid much attention. Only the security and privacy of biological information are insured, the biological technology can be better accepted and used by the public. In this paper, we propose a novel quantum bit(qbit)-based scheme to solve the security and privacy problem existing in the traditional fingerprint identification system. By exploiting the properties of quantum mechanics, our proposed scheme, cancelable remote quantum fingerprint templates protection scheme, can achieve the unconditional security guaranteed in an information-theoretical sense. Moreover, this novel quantum scheme can invalidate most of the attacks aimed at the fingerprint identification system. In addition, the proposed scheme is applicable to the requirement of remote communication with no need to worry about its security and privacy during the transmission. This is an absolute advantage when comparing with other traditional methods. Security analysis shows that the proposed scheme can effectively ensure the communication security and the privacy of users' information for the fingerprint identification.
Based on the definition of fractional Fourier transform(FrFT) in the cylindrical coordinate system,the propagation properties of a controllable dark-hollow beam(CDHB) are investigated in *** analytical formula is deri...
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Based on the definition of fractional Fourier transform(FrFT) in the cylindrical coordinate system,the propagation properties of a controllable dark-hollow beam(CDHB) are investigated in *** analytical formula is derived for the FrFT of a *** using the derived formula,the properties of a CDHB in the FrFT plane are illustrated *** results show that the properties of the intensity of the beam in the FrFT are closely related to not only the fractional order but also initial beam parameter,beam order and the lens focal length of the opticalsystem for performing *** derived formula provides an effective and convenient way for analyzing and calculating the FrFT of a CDHB.
With the development of both optical fiberbased communication and sensation, one interesting topic has been pointed out. How to connect those mountains of sensors to detect the signal in a large area, and how to make ...
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With the development of both optical fiberbased communication and sensation, one interesting topic has been pointed out. How to connect those mountains of sensors to detect the signal in a large area, and how to make the cost of sensing system lower enough should be studied.A network of sensors is a good option. All sensing equipments, including the interrogators and the sensors,will be internetworking together. However, fiber optic communicationnetworks have been developed very well over the past two decades. Is it necessary to rebuild a new network for sensors? In this paper, some new technologies in the two areas of fiber optic sensors and fiber optic communication will be addressed. Then, the available overlay architecture of a fiber optic sensors network will be presented. Finally, a polymorphous optical burst switching(POBS)-based architecture will be proposed, which can support all kinds of services, including digital data optical circuit/burst/packet switching and analog fiber optic sensor signal circuit/burst switching, etc.
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