Based on mutual authentication and dense coding,a novel revised efficient quantum direct communication scheme is proposed.It is composed of two phases：the quantum state distribution process and the direct communicati...Based on mutual authentication and dense coding,a novel revised efficient quantum direct communication scheme is proposed.It is composed of two phases：the quantum state distribution process and the direct communication process.The purpose of the former is to authenticate Trent and users to each other,and let the two legitimate users（Alice and Bob）safely share the Bell states.While the latter aims to make direct communication to transmit a secret message between Alice and Bob.In order to prevent from Eve＇s eavesdropping as well as to authenticate each other simultaneously,a decoy photon checking technique is applied.Compared with other analogous protocols,the quantum state distribution process is more simple and feasible and the proposed scheme is more efficient;i.e.,the total efficiency is almost 100%.Security analysis shows that the proposed scheme is secure against the eavesdropping attacks,the impersonation attacks,and some special Trent＇s attacks,including the attacks by using different initial states.展开更多
We present a novel protocol for deterministic secure quantum communication by using the lour-qubit cluster state as quantum channel. It is shown that two legitimate users can directly transmit the secret messages base...We present a novel protocol for deterministic secure quantum communication by using the lour-qubit cluster state as quantum channel. It is shown that two legitimate users can directly transmit the secret messages based on Bellbasis measurements and classical communication. The present protocol makes use of the ideas of block transmission and decoy particle checking technique. It has a high capacity as each cluster state can carry two 5its of information, and has a high intrinsic efficieney 5ecause almost all the instances except the decoy checking particles （its numSer is negligible） are useful. Furthermore, this protocol is feasible with present-day technique.展开更多
In this paper we propose two quantum secure direct communication (QSDC) protocols with authentication.The authentication key expansion method is introduced to improve the life of the keys with security.In the first sc...In this paper we propose two quantum secure direct communication (QSDC) protocols with authentication.The authentication key expansion method is introduced to improve the life of the keys with security.In the first scheme,the third party, called Trent is introduced to authenticate the users that participate in the communication.He sends thepolarized photons in blocks to authenticate communication parties Alice and Bob using the authentication keys.In thecommunication process, polarized single photons are used to serve as the carriers, which transmit the secret messagesdirectly.The second QSDC process with authentication between two parties is also discussed.展开更多
We propose two schemes for realizing quantum secure direct communication (QSDC)by using a set ofordered two-photon three-dimensional hyperentangled states entangled in two degrees of freedom (DOFs)as quantuminformatio...We propose two schemes for realizing quantum secure direct communication (QSDC)by using a set ofordered two-photon three-dimensional hyperentangled states entangled in two degrees of freedom (DOFs)as quantuminformation channels.In the first scheme,the photons from Bob to Alice are transmitted only once.After insuring thesecurity of the quantum channels,Bob encodes the secret message on his photons.Then Alice performs single-photontwo-DOF Bell bases measurements on her photons.This scheme has better security than former QSDC protocols.In thesecond scheme,Bob transmits photons to Alice twice.After insuring the security of the quantum channels,Bob encodesthe secret message on his photons.Then Alice performs two-photon Bell bases measurements on each DOF.The schemehas more information capacity than former QSDC protocols.展开更多
We show that the nonlinear equation governing wave propagation in a loss fibre system considered by Nakkeeran in J. Phys. A 34 (2001) 5111 can be brought into the standard nonlinear Schr?dinger equation by a simple tr...We show that the nonlinear equation governing wave propagation in a loss fibre system considered by Nakkeeran in J. Phys. A 34 (2001) 5111 can be brought into the standard nonlinear Schr?dinger equation by a simple transformation.展开更多
We propose a bidirectional quantum secure direct communication(QSDC) network protocol with the hyperentanglment in both the spatial-mode ad the polarization degrees of freedom of photon pairs which can in principle be...We propose a bidirectional quantum secure direct communication(QSDC) network protocol with the hyperentanglment in both the spatial-mode ad the polarization degrees of freedom of photon pairs which can in principle be produced with a beta barium borate crystal.The secret message can be encoded on the photon pairs with unitary operations in these two degrees of freedom independently.Compared with other QSDC network protocols,our QSDC network protocol has a higher capacity as each photon pair can carry 4 bits of information.Also,we discuss the security of our QSDC network protocol and its feasibility with current techniques.展开更多
A theoretical protocol of quantum dialogue is proposed,which uses a class of three-photon W states asquantum channel.After two-step security check,four-bit secret message can be transmitted to each other by transmitti...A theoretical protocol of quantum dialogue is proposed,which uses a class of three-photon W states asquantum channel.After two-step security check,four-bit secret message can be transmitted to each other by transmittingof single photon with the aid of two-bit classical information.展开更多
This paper devoted to report the design and the achievement of an optical communication subsystem with 12 parallel channels in one chip.The system is capable of transmitting 10 Gbps bidirectional date over hundreds of...This paper devoted to report the design and the achievement of an optical communication subsystem with 12 parallel channels in one chip.The system is capable of transmitting 10 Gbps bidirectional date over hundreds of meters.It can provide error detection and correction by using 8B/10B encoding and Cyclical Redundancy Checking (CRC) encoding when only single-channel fails.The design scheme has already passed the simulation in FPGA.This technique is useful to enhance the capability and the reliability of the very short reach (VSR) transmission systems.展开更多
Firstly,the JME（Jones matrix eigen） method is used to simulate the statistical characteristics of first- and second-order PMD in dispersion management system. Then,with help of the CNLSE （coupled nonlinear Schrodin...Firstly,the JME（Jones matrix eigen） method is used to simulate the statistical characteristics of first- and second-order PMD in dispersion management system. Then,with help of the CNLSE （coupled nonlinear Schrodinger equations） ,the effects of PMD on DMS （dispersion managed soliton） transmission is studied with a variational method. The simplified relationships of the statistical parameters of second-order and first-order of PMD in dispersion management system have been gotten,from which the detailed information of second-order can be obtained, if the condition of DGD is given. The results have shown that the first and second-order PMD （polarization mode dispersion） vectors influence the evolution of energy and Mean square of time displacement of DMS in high-speed bit rates systems. When DPMD^1st〉0.3 ps/km^1/2 ,we must consider some means of control（for example the filter） to restrain the PMD.展开更多
A high power and low distortion 1.31 μm AlGaInAs/InP multiquantum well distributed feedback laser diode (MQW DFB LD) with RWG structure has been developed by MOCVD technique. The fiber output power of butterfly packa...A high power and low distortion 1.31 μm AlGaInAs/InP multiquantum well distributed feedback laser diode (MQW DFB LD) with RWG structure has been developed by MOCVD technique. The fiber output power of butterfly packaged module with optic isolator P f is more than 10 mW, threshold current is in the range of (13～20) mA, slope efficiency, E s>0.30 W/A and side mode suppression ratio, R S,M,S >35 dB. The composite second order, O C,S <-61 dBc and composite triple beat, B C,T <-65 dBc are obtained by test frequencies of (45～550) MHz with 60 PAL channels. In the test conditions the carrier to noise ratio, R C,N >51 dB.展开更多
基金The National Natural Science Foundation of China(No.60873101)the Natural Science Foundation of Jiangsu Province(No.BK2008209)the Research Foundation of Nanjing University of Information Science and Technology(No.20080298)
文摘Based on mutual authentication and dense coding,a novel revised efficient quantum direct communication scheme is proposed.It is composed of two phases：the quantum state distribution process and the direct communication process.The purpose of the former is to authenticate Trent and users to each other,and let the two legitimate users（Alice and Bob）safely share the Bell states.While the latter aims to make direct communication to transmit a secret message between Alice and Bob.In order to prevent from Eve＇s eavesdropping as well as to authenticate each other simultaneously,a decoy photon checking technique is applied.Compared with other analogous protocols,the quantum state distribution process is more simple and feasible and the proposed scheme is more efficient;i.e.,the total efficiency is almost 100%.Security analysis shows that the proposed scheme is secure against the eavesdropping attacks,the impersonation attacks,and some special Trent＇s attacks,including the attacks by using different initial states.
基金supported by the Postgraduate Innovation Research Plan from Anhui University under Grant No.20073039
文摘We present a novel protocol for deterministic secure quantum communication by using the lour-qubit cluster state as quantum channel. It is shown that two legitimate users can directly transmit the secret messages based on Bellbasis measurements and classical communication. The present protocol makes use of the ideas of block transmission and decoy particle checking technique. It has a high capacity as each cluster state can carry two 5its of information, and has a high intrinsic efficieney 5ecause almost all the instances except the decoy checking particles （its numSer is negligible） are useful. Furthermore, this protocol is feasible with present-day technique.
基金Supported by the National Fundamental Research Program under Grant No.2010CB923202Specialized Research Fund for the Doctoral Program of Education Ministry of China under Grant No.20090005120008+1 种基金 the Fundamental Research Funds for the Central Universities under Grant No.BUPT2009RC0710 China National Natural Science Foundation under Grant Nos.60871082,60937003 and 10947151
文摘In this paper we propose two quantum secure direct communication (QSDC) protocols with authentication.The authentication key expansion method is introduced to improve the life of the keys with security.In the first scheme,the third party, called Trent is introduced to authenticate the users that participate in the communication.He sends thepolarized photons in blocks to authenticate communication parties Alice and Bob using the authentication keys.In thecommunication process, polarized single photons are used to serve as the carriers, which transmit the secret messagesdirectly.The second QSDC process with authentication between two parties is also discussed.
基金Supported by the National Natural Science Foundations of China under Grant Nos. 10904066 and 11004096the State Key Program for Basic Research of China under Grant No. 2011CBA00205
文摘We propose two schemes for realizing quantum secure direct communication (QSDC)by using a set ofordered two-photon three-dimensional hyperentangled states entangled in two degrees of freedom (DOFs)as quantuminformation channels.In the first scheme,the photons from Bob to Alice are transmitted only once.After insuring thesecurity of the quantum channels,Bob encodes the secret message on his photons.Then Alice performs single-photontwo-DOF Bell bases measurements on her photons.This scheme has better security than former QSDC protocols.In thesecond scheme,Bob transmits photons to Alice twice.After insuring the security of the quantum channels,Bob encodesthe secret message on his photons.Then Alice performs two-photon Bell bases measurements on each DOF.The schemehas more information capacity than former QSDC protocols.
文摘We show that the nonlinear equation governing wave propagation in a loss fibre system considered by Nakkeeran in J. Phys. A 34 (2001) 5111 can be brought into the standard nonlinear Schr?dinger equation by a simple transformation.
基金Supported by the Natural Science Foundation of Jiangsu Provincial Universities under Grant No.10KJB180004the National Natural Science Foundation of China under Grant No.11105075
文摘We propose a bidirectional quantum secure direct communication(QSDC) network protocol with the hyperentanglment in both the spatial-mode ad the polarization degrees of freedom of photon pairs which can in principle be produced with a beta barium borate crystal.The secret message can be encoded on the photon pairs with unitary operations in these two degrees of freedom independently.Compared with other QSDC network protocols,our QSDC network protocol has a higher capacity as each photon pair can carry 4 bits of information.Also,we discuss the security of our QSDC network protocol and its feasibility with current techniques.
基金Supported by the National Natural Science Foundation of China under Grant No.10704011the Research Programs of the Educational Office of Liaoning Province under Grant No.2008006
文摘A theoretical protocol of quantum dialogue is proposed,which uses a class of three-photon W states asquantum channel.After two-step security check,four-bit secret message can be transmitted to each other by transmittingof single photon with the aid of two-bit classical information.
文摘This paper devoted to report the design and the achievement of an optical communication subsystem with 12 parallel channels in one chip.The system is capable of transmitting 10 Gbps bidirectional date over hundreds of meters.It can provide error detection and correction by using 8B/10B encoding and Cyclical Redundancy Checking (CRC) encoding when only single-channel fails.The design scheme has already passed the simulation in FPGA.This technique is useful to enhance the capability and the reliability of the very short reach (VSR) transmission systems.
文摘Firstly,the JME（Jones matrix eigen） method is used to simulate the statistical characteristics of first- and second-order PMD in dispersion management system. Then,with help of the CNLSE （coupled nonlinear Schrodinger equations） ,the effects of PMD on DMS （dispersion managed soliton） transmission is studied with a variational method. The simplified relationships of the statistical parameters of second-order and first-order of PMD in dispersion management system have been gotten,from which the detailed information of second-order can be obtained, if the condition of DGD is given. The results have shown that the first and second-order PMD （polarization mode dispersion） vectors influence the evolution of energy and Mean square of time displacement of DMS in high-speed bit rates systems. When DPMD^1st〉0.3 ps/km^1/2 ,we must consider some means of control（for example the filter） to restrain the PMD.
文摘A high power and low distortion 1.31 μm AlGaInAs/InP multiquantum well distributed feedback laser diode (MQW DFB LD) with RWG structure has been developed by MOCVD technique. The fiber output power of butterfly packaged module with optic isolator P f is more than 10 mW, threshold current is in the range of (13～20) mA, slope efficiency, E s>0.30 W/A and side mode suppression ratio, R S,M,S >35 dB. The composite second order, O C,S <-61 dBc and composite triple beat, B C,T <-65 dBc are obtained by test frequencies of (45～550) MHz with 60 PAL channels. In the test conditions the carrier to noise ratio, R C,N >51 dB.
