高效SPAD光子探测器及量子随机源的研究
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摘要
二十世纪是量子力学在应用领域取得突破性进展的一个世纪，量子的不可分解性和纠缠特性作为量子力学的两大显著特征成为了量子保密通信实现应用的基石。量子保密通信是以单光子为信息载体，基于随机数信息编码，由量子力学的基本原理保证安全性的保密通信方案。选用单光子雪崩二极管(SPAD)作为单光子的探测器件，单光子探测器的性能是决定量子保密通信的作用距离、误差率等指标的关键。另外，获得真随机数是实现量子保密通信安全密钥分发的重要单元技术。为此本论文的研究目的就在于提高单光子探测器的性能，实现单光子的路由操控，获得实用化的真随机源以完成对单光子的安全信息编码。研究工作主要包括以下三个方面。
第一，提出多种SPAD工作电路方案，提高了雪崩信号的输出幅值，获得了高计数率的标准TTL通信信号。目前广泛采用的单光子探测器工作电路主要采用SPAD的被动淬灭工作方式，这种单光子探测器工作电路有两个比较明显的缺点，其一是光子探测所产生的雪崩信号的幅值太低(20-30mV)，不利于雪崩信号的采集和处理；其二是光子探测所产生的雪崩信号之间的时间间隔太长，即雪崩恢复过程的等待时间(死时间)太长，导致恢复时间内单光子信号的丢失，计数率降低，探测器的性能下降。本论文对SPAD工作性质的研究主要就针对解决这两个问题而提出。首先，针对小幅值雪崩信号输出问题我们提出采用小电容提供交流通道方案改进了原有的SPAD雪崩被动淬灭电路，对雪崩信号的幅值实现了一个量级的提高。改进后电路输出的雪崩信号可以很容易的触发信号处理电路中的比较器，缩减了雪崩信号的放大过程，简化了雪崩信号的采集步骤。同时，设计出可靠实用的雪崩信号处理电路，获得了很好的TTL数字通信信号(申请中国专利：03230983.x)。再次，为了进一步提高SPAD的性能，解决死时间太长的问题，我们提出采用主动快恢复技术，设计了缩短死时间的被动—主动相结合的雪崩淬灭电路，制作出高量子效率、低噪声、短死时间的SPAD光子探测器，探测器的死时间由原来的>2us缩短为<100ns，计数率提高了1个数量级(申请中国专利：03141680.2)。进一步利用TAC／MCA技术对SPAD输出信号进行了光子自相关测量，研究了两个相邻单光子计数脉冲时间分布统计效应，直接观测到了采用被动—主动混合抑制技术后死时间的改善(《半导体光电》发表文章)。
论文摘要
第二，验证了基于光量子偏振特性的真随机源方案并实现了系统的集成化
和实用化。首先讨论随机数的数学机理，研究数学和物理上获得随机数的方案。
针对量子保密通信对真随机数的要求，基于单个光子在分束器两侧所表现出来
的量子随机性，讨论了几种获得真随机数的方案。其次，着重研究了基于单个
光子在偏振分束镜两侧偏振分束所表现出的随机特性获得真随机数的实验方
案。首先从可行性的角度对实验方案进行了求证，获得了二进制随机码的嫡值
0.999999等很好地随机结果(((物理学报》发表文章)。最后，从实用性的角度
出发，实现了结构紧凑、实用化、集成化的随机数发生器。巧妙设计LD驱动电
路和调制电路，获得了低输出功率、结构紧凑、高频调制的LD脉冲光源，经衰
减后满足准单光子源的要求;利用高效SPAD光子探测器探测随机信号，获得高
计数率的随机数信号;同时采用同步符合技术提取有效信号;再送入数据采集
卡采集信号，在计算机中记录下所得到的二进制随机码;最后采用国际通用的
随机数检测程序(ENT)直接对二进制随机码进行随机性分析。
第三，实现了空间和光纤中对单光子的路由操控。基于M一Z干涉仪原理，采
用多种方案分别对空间和光纤中的单光子路由操控进行研究，验证了对单光子路
由操控的可行性，实现了光子在节点上的路由(((光子学报》发表文章)。对量子
电路中各种逻辑电路的光学实现进行可行性分析，并将对单个光子在光学节点上
有序操控的研究作为量子网络发展的一项关键单元技术，旨在未来量子网络的研
究中得到更为广泛的应用。
Twentieth century is the century that quantum mechanics have made prominent progress in application field. The most peculiar characteristics of quantum mechanics are the existence of indivisible quanta and of entangled systems. Both of these lie at the root of quantum cryptography. Quantum cryptography could well be the first application of quantum mechanics at the single-quantum level. As the transmission of information is based on single photon, so we choose SPAD( single photon avalanche diode) as the detector. Performance of SPAD would be the vital key to decide transmission distance, error rate, and so on for the cryptography system. The key used in the one-time pad must be secret and used only once. All secure cryptosystems, both classical and quantum ones, require truly random numbers. Thus We put improving the performance of SPAD and producing truly random numbers as the two main jobs of this article.
First, Designing various working circuits for SPAD to improve working performance. Passive quenching circuit is the most common working mode for SPAD in application. The two main limitations for this circuit are that the lower output amplitude of the avalanche signal which would make trouble for the latter signal executing circuit and the longer dead time (the time interval between two avalanche signals) which would make the detector lose avalanche signal, thus decreasing counting rate and lower the efficiency of detector. The main purpose of studying the high efficient SPAD is to resolve the two problems on SPAD. To improve the output amplitude, the scheme of adding AC channelduring SPAD discharge period with a little capacitance in the passive quenching circuit has realized the purpose of improving the avalanche output from 20-30mV to 120-130mV. A compact and efficient avalanche signal executing circuit has been designed to make the signal be the TTL signal to satisfy the requirement of transmission ( apply Chinese patent: 03230983. x ).A mixed passive-active
quenching circuit with active fast restoring technology described in this article is to reduce the dead time and get higher counts. The single photon detector is developed successfully with higher quantum efficiency, lower noise and shorter dead time. Excellent experiment results have been got: dead time <100ns, counts>5MHz(apply Chinese patent: 03141680.2) .We do research on the autocorrelation of the output of SPAD in passive and mixed passive-active quenching modes respectively with TAC/MCA technology. And good graphs well justify our results on improving dead time with analysis on statistical time distributing of two neighboring avalanche signals (publish article on < ).
Second, A quantum random number generator scheme on the basis of photon random routing chosen charactristics at a polarizing beam splitter has been justified. And A fast and compact random number generator has been produced. We well study function principle of the random number and make an investigation on the realization schemes of random number generator, both in Physics and Mathematics .Various schemes have been discussed in this article to get true random number to satisfy the requirement of quantum cryptography. Based on the random choice of a single photon at a polarizing beam splitter, a quantum Mechanical source of true random number is realized( publish article on <). To satisfy compact housings and simple to operate in practice, a fast and compact quantum random number generator has been produced in our laboratory. A compact and 10MHz modulated LD is attenuated to be approximate single photon source. High efficiency SPAD photon detector, synchronous single photon coincidence detection technique, and data collection card based on LPT port are put into practice and generating a binary random number at a rate of >1MHz/s. Perfect result on randomness has been tested by the Pseudorandom Number Sequence Test Program (ENT).
Third, Doing experiment on single-photon routing control both on
space and fiber interface. As s
第一，提出多种SPAD工作电路方案，提高了雪崩信号的输出幅值，获得了高计数率的标准TTL通信信号。目前广泛采用的单光子探测器工作电路主要采用SPAD的被动淬灭工作方式，这种单光子探测器工作电路有两个比较明显的缺点，其一是光子探测所产生的雪崩信号的幅值太低(20-30mV)，不利于雪崩信号的采集和处理；其二是光子探测所产生的雪崩信号之间的时间间隔太长，即雪崩恢复过程的等待时间(死时间)太长，导致恢复时间内单光子信号的丢失，计数率降低，探测器的性能下降。本论文对SPAD工作性质的研究主要就针对解决这两个问题而提出。首先，针对小幅值雪崩信号输出问题我们提出采用小电容提供交流通道方案改进了原有的SPAD雪崩被动淬灭电路，对雪崩信号的幅值实现了一个量级的提高。改进后电路输出的雪崩信号可以很容易的触发信号处理电路中的比较器，缩减了雪崩信号的放大过程，简化了雪崩信号的采集步骤。同时，设计出可靠实用的雪崩信号处理电路，获得了很好的TTL数字通信信号(申请中国专利：03230983.x)。再次，为了进一步提高SPAD的性能，解决死时间太长的问题，我们提出采用主动快恢复技术，设计了缩短死时间的被动—主动相结合的雪崩淬灭电路，制作出高量子效率、低噪声、短死时间的SPAD光子探测器，探测器的死时间由原来的>2us缩短为<100ns，计数率提高了1个数量级(申请中国专利：03141680.2)。进一步利用TAC／MCA技术对SPAD输出信号进行了光子自相关测量，研究了两个相邻单光子计数脉冲时间分布统计效应，直接观测到了采用被动—主动混合抑制技术后死时间的改善(《半导体光电》发表文章)。
论文摘要
第二，验证了基于光量子偏振特性的真随机源方案并实现了系统的集成化
和实用化。首先讨论随机数的数学机理，研究数学和物理上获得随机数的方案。
针对量子保密通信对真随机数的要求，基于单个光子在分束器两侧所表现出来
的量子随机性，讨论了几种获得真随机数的方案。其次，着重研究了基于单个
光子在偏振分束镜两侧偏振分束所表现出的随机特性获得真随机数的实验方
案。首先从可行性的角度对实验方案进行了求证，获得了二进制随机码的嫡值
0.999999等很好地随机结果(((物理学报》发表文章)。最后，从实用性的角度
出发，实现了结构紧凑、实用化、集成化的随机数发生器。巧妙设计LD驱动电
路和调制电路，获得了低输出功率、结构紧凑、高频调制的LD脉冲光源，经衰
减后满足准单光子源的要求;利用高效SPAD光子探测器探测随机信号，获得高
计数率的随机数信号;同时采用同步符合技术提取有效信号;再送入数据采集
卡采集信号，在计算机中记录下所得到的二进制随机码;最后采用国际通用的
随机数检测程序(ENT)直接对二进制随机码进行随机性分析。
第三，实现了空间和光纤中对单光子的路由操控。基于M一Z干涉仪原理，采
用多种方案分别对空间和光纤中的单光子路由操控进行研究，验证了对单光子路
由操控的可行性，实现了光子在节点上的路由(((光子学报》发表文章)。对量子
电路中各种逻辑电路的光学实现进行可行性分析，并将对单个光子在光学节点上
有序操控的研究作为量子网络发展的一项关键单元技术，旨在未来量子网络的研
究中得到更为广泛的应用。
Twentieth century is the century that quantum mechanics have made prominent progress in application field. The most peculiar characteristics of quantum mechanics are the existence of indivisible quanta and of entangled systems. Both of these lie at the root of quantum cryptography. Quantum cryptography could well be the first application of quantum mechanics at the single-quantum level. As the transmission of information is based on single photon, so we choose SPAD( single photon avalanche diode) as the detector. Performance of SPAD would be the vital key to decide transmission distance, error rate, and so on for the cryptography system. The key used in the one-time pad must be secret and used only once. All secure cryptosystems, both classical and quantum ones, require truly random numbers. Thus We put improving the performance of SPAD and producing truly random numbers as the two main jobs of this article.
First, Designing various working circuits for SPAD to improve working performance. Passive quenching circuit is the most common working mode for SPAD in application. The two main limitations for this circuit are that the lower output amplitude of the avalanche signal which would make trouble for the latter signal executing circuit and the longer dead time (the time interval between two avalanche signals) which would make the detector lose avalanche signal, thus decreasing counting rate and lower the efficiency of detector. The main purpose of studying the high efficient SPAD is to resolve the two problems on SPAD. To improve the output amplitude, the scheme of adding AC channelduring SPAD discharge period with a little capacitance in the passive quenching circuit has realized the purpose of improving the avalanche output from 20-30mV to 120-130mV. A compact and efficient avalanche signal executing circuit has been designed to make the signal be the TTL signal to satisfy the requirement of transmission ( apply Chinese patent: 03230983. x ).A mixed passive-active
quenching circuit with active fast restoring technology described in this article is to reduce the dead time and get higher counts. The single photon detector is developed successfully with higher quantum efficiency, lower noise and shorter dead time. Excellent experiment results have been got: dead time <100ns, counts>5MHz(apply Chinese patent: 03141680.2) .We do research on the autocorrelation of the output of SPAD in passive and mixed passive-active quenching modes respectively with TAC/MCA technology. And good graphs well justify our results on improving dead time with analysis on statistical time distributing of two neighboring avalanche signals (publish article on <
Second, A quantum random number generator scheme on the basis of photon random routing chosen charactristics at a polarizing beam splitter has been justified. And A fast and compact random number generator has been produced. We well study function principle of the random number and make an investigation on the realization schemes of random number generator, both in Physics and Mathematics .Various schemes have been discussed in this article to get true random number to satisfy the requirement of quantum cryptography. Based on the random choice of a single photon at a polarizing beam splitter, a quantum Mechanical source of true random number is realized( publish article on <
Third, Doing experiment on single-photon routing control both on
space and fiber interface. As s
引文
[1] Bennett, C.H., F. Bessette, G. Brassard, L. Salvail, and J. Smolin, 1992, "Experimental quantum cryptography," J. Cryptology 5, 3-28.
[2] Townsend, P., 1994, "Secure key distribution system cryptographyic key distribution system based on quantum cryptography," Electron. Lett. 30, 809-811.
[3] Bennett, C.H., and G. Brassard, 1985, "Quantum public key distribution system," IBM Tech. Discl. Bull. 28,3153-3163.
[4] Bennett, C.H., G. Brassard, and A. Ekert, 1992, "Quantum cryptography," Sci. Am. 267, 50-57.
[5] Bourennane, M., F. Gibson, A. Karlsson, A. Hening, P. Jonsson, T. Tsegaye, D. Ljunggren, and E. Sunderg, 1999, "Experiments on long wavelength(1550nm) 'plug and play' quantum cryptography system," Opt. Express 4,383-387.
[6] Bourennane, M., A. Karlsson, G. Bj?rn, N. Gisin, and N. Cerf, 2001, "Quantum key distribution using multilevel encoding: security
analysis," preprint quant-ph/O106049.
[7] Braginsky, V. B., and F.Y. Khalili, 1992, Quantum Measurement.
[8] Brassard, G., 1988, Modern Cryptolog: A Tutorial, Lecture Notes in Computer Science, Vol. 325(Springer, New York).
[9] Ekert, A.K., 1999, "Quantum cryptography based on Bell'S theorem," Phys. Rev. Lett. 67, 661-663.
[10] Hillery, M., V. Buzek, and A. Berthiaume, 1999, "Quantum secret sharing," Phys. Rev. A59, 1829-1834.
[11] Hughes, R.,G. Morgan, and C. Peterson, 2000, "Quantum key distribution over a 48-km optical fiber network," J. Mod. Opt. 47, 533-547.
[12] Huttner, B., N. Imoto, and S. M. Barnett, 1996, "Short distance applications of quantum cryptography," J. Nonlinear Opt. Phys. Mater. 5, 823-832.
[13] Huttner, B., N. Imoto, N. Gisin, and T. Mor, 1995, "Quantum cryptography with coherent states," Phys. Rev. A51, 1863-1869.
[14] Jacob, B., and J. Franson, 1996, "Quantum cryptography in free space," Opt. Lett. 21, 1854-1856.
[15] L?tkenhaus, N., 2000, "Security against individual attacks for realistic quantum key distribution over distances as long as 30km," Opt. Lett. 20, 1695-1697.
[16] Maurer, U.M., 1993, "Secret key agreement by public discussion from common information." IEEE Trans. Inf. Theory 39.733-742.
[17] Maurer, U.M., and S. Wolf, 1999, "Uncondionally secure key agreement and intrinsic information," IEEE Trans. Inf. Theory 45, 499-514.
[18] Muller, A., H. Zbinden, and N. Gisin, 1996, "Quantum cryptography over 23km in installed under-lake telecom fibre," Europhys. Lett. 33, 335-339.
[19] Muller, A., J. Breguet, and N. Gisin. 1993. "Experimental demonstration of quantum cryptography using polarized photons in optical fiber over more than 1km," Europhys. Lett. 23. 383-388.
[20] Naik, D., C. Peterson, A. White, A. Berglund, and P. Kwiat, 2000, "Entangled state quantum cryptography: eavesdropping on the Ekert protocol," Phys. Rev. Lett. 84, 4833-4736.
[21] Shor, P.W., and J. Preskill, 2000, "Simple proof of security of the BB84 quantum key distribution protocol." Phy. Rev. Lett. 85, 441-444.
[22] C. H. Bennett, Phys. Rev. Lett. 68,3121(1992);A.K. Ekert, Nature, 358,14(1992).
[23] D Stucki, N Gisin, O Guinnard, G Ribordy and H zbinden, "Quantum key distribution over 67km with a plug&play system", New Journal of physics 4(2002) 41.1-41.8.
[24] 周春源，吴光，陈修亮，李和祥，曾和平，“50千米光纤中量子保密通信”，中国科学(G辑)2003．4．
[25] Matth?us Halder, Patrick zard?, Christian kurtsiefer, Harald
weinfurter Phil Gorman, Paul Tapster, John Rarity, "Compact Long Distance Quantum Cryptography", experimental quantum physics.
[26] T. Jennewein, U. Achleitner, G. Weihs, H. Weinfurter, A. Zeilinger, A Fast and Compact Quantum Random Number Generator(Los Alamos Eprint, quant-ph/9912118).
[27] A. J. Martino, G. M. Morris, Applied Optics 30 981(1991).
[28] G. M. Morris, Opt. Engin. 24 861985; J. Marron, A. J. Martino, G. M. Morris, Applied Optics 25 26(1986).
[29] W. M. Itano, J. C. Bergquist, R. G. Hulet, and D. J. Wineland, Phys. Rev. Lett. 59 2732(1987).
[30] Th. Sauter, W. Neuhauser, R. Blatt, and P. E. Toschek, Phys. Rev. Lett. 57 1696(1986).
[2] Townsend, P., 1994, "Secure key distribution system cryptographyic key distribution system based on quantum cryptography," Electron. Lett. 30, 809-811.
[3] Bennett, C.H., and G. Brassard, 1985, "Quantum public key distribution system," IBM Tech. Discl. Bull. 28,3153-3163.
[4] Bennett, C.H., G. Brassard, and A. Ekert, 1992, "Quantum cryptography," Sci. Am. 267, 50-57.
[5] Bourennane, M., F. Gibson, A. Karlsson, A. Hening, P. Jonsson, T. Tsegaye, D. Ljunggren, and E. Sunderg, 1999, "Experiments on long wavelength(1550nm) 'plug and play' quantum cryptography system," Opt. Express 4,383-387.
[6] Bourennane, M., A. Karlsson, G. Bj?rn, N. Gisin, and N. Cerf, 2001, "Quantum key distribution using multilevel encoding: security
analysis," preprint quant-ph/O106049.
[7] Braginsky, V. B., and F.Y. Khalili, 1992, Quantum Measurement.
[8] Brassard, G., 1988, Modern Cryptolog: A Tutorial, Lecture Notes in Computer Science, Vol. 325(Springer, New York).
[9] Ekert, A.K., 1999, "Quantum cryptography based on Bell'S theorem," Phys. Rev. Lett. 67, 661-663.
[10] Hillery, M., V. Buzek, and A. Berthiaume, 1999, "Quantum secret sharing," Phys. Rev. A59, 1829-1834.
[11] Hughes, R.,G. Morgan, and C. Peterson, 2000, "Quantum key distribution over a 48-km optical fiber network," J. Mod. Opt. 47, 533-547.
[12] Huttner, B., N. Imoto, and S. M. Barnett, 1996, "Short distance applications of quantum cryptography," J. Nonlinear Opt. Phys. Mater. 5, 823-832.
[13] Huttner, B., N. Imoto, N. Gisin, and T. Mor, 1995, "Quantum cryptography with coherent states," Phys. Rev. A51, 1863-1869.
[14] Jacob, B., and J. Franson, 1996, "Quantum cryptography in free space," Opt. Lett. 21, 1854-1856.
[15] L?tkenhaus, N., 2000, "Security against individual attacks for realistic quantum key distribution over distances as long as 30km," Opt. Lett. 20, 1695-1697.
[16] Maurer, U.M., 1993, "Secret key agreement by public discussion from common information." IEEE Trans. Inf. Theory 39.733-742.
[17] Maurer, U.M., and S. Wolf, 1999, "Uncondionally secure key agreement and intrinsic information," IEEE Trans. Inf. Theory 45, 499-514.
[18] Muller, A., H. Zbinden, and N. Gisin, 1996, "Quantum cryptography over 23km in installed under-lake telecom fibre," Europhys. Lett. 33, 335-339.
[19] Muller, A., J. Breguet, and N. Gisin. 1993. "Experimental demonstration of quantum cryptography using polarized photons in optical fiber over more than 1km," Europhys. Lett. 23. 383-388.
[20] Naik, D., C. Peterson, A. White, A. Berglund, and P. Kwiat, 2000, "Entangled state quantum cryptography: eavesdropping on the Ekert protocol," Phys. Rev. Lett. 84, 4833-4736.
[21] Shor, P.W., and J. Preskill, 2000, "Simple proof of security of the BB84 quantum key distribution protocol." Phy. Rev. Lett. 85, 441-444.
[22] C. H. Bennett, Phys. Rev. Lett. 68,3121(1992);A.K. Ekert, Nature, 358,14(1992).
[23] D Stucki, N Gisin, O Guinnard, G Ribordy and H zbinden, "Quantum key distribution over 67km with a plug&play system", New Journal of physics 4(2002) 41.1-41.8.
[24] 周春源，吴光，陈修亮，李和祥，曾和平，“50千米光纤中量子保密通信”，中国科学(G辑)2003．4．
[25] Matth?us Halder, Patrick zard?, Christian kurtsiefer, Harald
weinfurter Phil Gorman, Paul Tapster, John Rarity, "Compact Long Distance Quantum Cryptography", experimental quantum physics.
[26] T. Jennewein, U. Achleitner, G. Weihs, H. Weinfurter, A. Zeilinger, A Fast and Compact Quantum Random Number Generator(Los Alamos Eprint, quant-ph/9912118).
[27] A. J. Martino, G. M. Morris, Applied Optics 30 981(1991).
[28] G. M. Morris, Opt. Engin. 24 861985; J. Marron, A. J. Martino, G. M. Morris, Applied Optics 25 26(1986).
[29] W. M. Itano, J. C. Bergquist, R. G. Hulet, and D. J. Wineland, Phys. Rev. Lett. 59 2732(1987).
[30] Th. Sauter, W. Neuhauser, R. Blatt, and P. E. Toschek, Phys. Rev. Lett. 57 1696(1986).