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量子信息中隐形传输与逻辑操作的理论研究

量子信息中隐形传输与逻辑操作的理论研究

作者：祁春超华中科技大学

学位级别：硕士

目前,随着人们对信息的需求日益增加,人们将会逐渐将现有的信息系统功能开发至最大极限。因此信息科学的进一步发展势必要借助于新的原理和方法,于是将量子力学与信息科学相结合而产生的一门新兴学科-量子信息学便产生了。量子信息用量... 详细信息

目前,随着人们对信息的需求日益增加,人们将会逐渐将现有的信息系统功能开发至最大极限。因此信息科学的进一步发展势必要借助于新的原理和方法,于是将量子力学与信息科学相结合而产生的一门新兴学科-量子信息学便产生了。量子信息用量子态编码,具有经典信息没有的特殊性质,其特有的量子纠缠特性使得量子信息理论比经典信息科学在某些方面更具有优势。本论文的工作主要分为以下五个方面: （1）阐述了原子与光场的相互作用。原子与光场相互作用理论是利用原子-腔系统实现量子信息操作的理论基础。加深对原子-光场相互作用系统演化规律的了解,有利于基于原子-腔系统量子纠缠态制备方案的研究。本文将重点介绍三种制备纠缠态的方法:原子-腔系统中原子纠缠态制备,两模光场纠缠态的制备,参量下转换器光子纠缠态的制备。（2）介绍了量子通信与量子计算的基本理论。主要阐述了量子比特、量子门、纠缠态、隐形态传输、量子不可克隆定理、量子稠密编码等基础理论知识。（3）分析了量子逻辑操作。主要通过线性光学元件,辅助光,路由选择原理,Bell态测量及泡利变换,最终可实现一系列量子逻辑操作。（4）讨论了基于电荷探测器的电子的隐形态传输与量子逻辑运算方案,有效地提高了操作的成功概率。该方案主要利用电荷探测器、Bell分析器、Hadamard门变换、辅助电子及电子偏振光束分离器。

关键词：量子通信纠缠态电荷探测器隐形态传输量子逻辑操作

基于600-2000nm抽运源的太赫兹相干光源的最新进展

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物理学报 2011年第9期60卷 873-881页

作者：祁春超欧阳征标深圳大学太赫兹技术研究中心深圳市微纳光子信息技术重点实验室深圳大学电子科学与技术学院深圳518060

最近几年,紧凑型、便携式、低廉、可调谐的太赫兹波源由于具有广泛的应用前景因而成为太赫兹领域的研究焦点.波长为600—2000nm范围的近红外光源由于具有体积紧凑、价格低廉、频率可调谐和工作稳定的特点,所以频繁被选为太赫兹波产生的... 详细信息

最近几年,紧凑型、便携式、低廉、可调谐的太赫兹波源由于具有广泛的应用前景因而成为太赫兹领域的研究焦点.波长为600—2000nm范围的近红外光源由于具有体积紧凑、价格低廉、频率可调谐和工作稳定的特点,所以频繁被选为太赫兹波产生的抽运源.本文着重从双波长可调谐抽运源、内腔光参量振荡器太赫兹发生器两个方面进行了较系统的阐述.分析表明,近红外相对中红外双波长抽运光源由于具有更紧凑的结构而成为研究热点;差频和非线性级联过程由于具有调谐范围宽的特点而成为产生太赫兹辐射的重要手段.

关键词：太赫兹辐射近红外波段调谐宽度非线性级联过程

Transmittance investigation on capacitive mesh on thick dielectric substrates as output windows for optically pumped terahertz lasers

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Chinese Physics B 2010年第11期19卷 389-394页

作者：祁春超左都罗卢彦兆唐建程祖海 Wuhan National Laboratory for Optoelectronics College of Optoelectronic Science and EngineeringHuazhong University of Science and Technology

This paper reports that an output window for optically pumped terahertz （THz） laser has been fabricated by depositing a capacitive nickel-mesh on a thick high-resistivity silicon substrate （approximating to 5 mm thick）. Unlike the conventional process of depositing a gold film approximating to 100 nm on negative photoresist using electron-beam evaporation, a nickel film approximating to 1.5 μm thick is directly deposited on the clean surface of dielectric substrate using magnetron sputtering and then a positive photoresist is spun onto the nickel metal surface at 6000 r for 60 s. A transmittance spectrum of the output window in a certain frequency range （say, from zero to 1 THz） has been obtained by using THz time domain spectroscopy. Moreover a transmittance spectrum simulated numerically has also been estimated with respect to the output window using the transmission-line model （TLM） containing attenuation component from dielectric substrate. The simulation results show that the TLM can explain well the experimental curve in a certain frequency range from zero to 1 THz. Thus it is demonstrated that the improved optical component can be efficiently used as both output coupler and output window for optically pumped THz lasers.

关键词： physical optics capacitive mesh structure output coupler optically pumped Terahertz laser

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基于光放大的长脉冲抽运太赫兹激光

物理学报 2009年第7期58卷 4641-4646页

作者：祁春超左都罗孟凡奇卢彦兆纠智先程祖海武汉光电国家实验室华中科技大学光电子科学与工程学院武汉430074

为了获得较窄增益带宽、较大光强的太赫兹辐射,尝试了利用TEACO2激光器对6 W可调谐连续波CO2种子激光实行双程光放大实验,以期望获得长脉冲、高峰值功率的抽运光.通过实验,获得了大约30倍的放大系数,放大光输出功率随种子光注入功率的... 详细信息

为了获得较窄增益带宽、较大光强的太赫兹辐射,尝试了利用TEACO2激光器对6 W可调谐连续波CO2种子激光实行双程光放大实验,以期望获得长脉冲、高峰值功率的抽运光.通过实验,获得了大约30倍的放大系数,放大光输出功率随种子光注入功率的增加而增加,其中10 P(20)支线表现更加突出,并且被放大的激光支线半峰全宽在14μs左右.基于这种长脉冲抽运源,建立了一种产生脉冲太赫兹的动力学模型,给出了产生太赫兹辐射的饱和抽运光强表达式,确定了抽运光的光强范围.另外,通过对动力学模型含时解的推导,得到了太赫兹增益介质吸收抽运光能量的表达式.分析表明:对于强抽运光,这种长脉冲激光可能更适合充当重分子太赫兹增益介质的抽运源;而对于较弱抽运光,几乎不能形成转动能级间的粒子数反转,因而无太赫兹辐射产生.

关键词：激光物理长脉冲动力学模型太赫兹激光

Theoretical Design of a Wedged Output Coupler Coated by Capacitive Strip-Grating for Optically Pumped Terahertz Lasers

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Chinese Physics Letters 2010年第4期27卷 126-129页

作者：祁春超左都罗孟凡奇程祖海 Wuhan National Laboratory for Optoelectronics Wuhan 430074 College of Optoelectronic Science and Engineering Huazhong University of Science and Technology Wuhan 430074

An output coupler for optically pumped terahertz laser consisting of capacitive strip-grating and wedged high- resistivity silicon substrate is designed theoretically and its transmittance performance is also discussed. The etalon effects frequently occurring in previous experiments are effectively suppressed, and thus a fiat and accurate transmittance spectrum is obtained in a narrow wavenumber interval of 2 cm^-1 near a particular center wavenumber. Furthermore the transmittance sensitivity to the slight shift of substrate thickness is also completely eliminated. The wedged output coupler is easy to fabricate and its substrate may be used repeatedly to meet various transmittance requirements.

关键词： Optics quantum optics and lasers

Generation of Intense THz Pulsed Lasers Pumped Strongly by CO2 Pulsed Lasers

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Chinese Physics Letters 2009年第6期26卷 113-116页

作者：祁春超程祖海 Wuhan National Laboratory for Optoelectronics Huazhong University of Science and Technology Wuhan 430074 College of Optoelectronic Science and Engineering Huazhong University of Science and Technology Wuhan 430074

A theoretical method dealing with two intense laser fields interacting with a three-level molecular system is proposed. A discussion is presented on the properties of the solutions for time-independent and time-dependent absorption coefficients and gain coefficient on resonance for strong laser fields, based on analytic evaluation of the rate equations for a homogeneously broadened, three-level molecular system. The pump intensity range can be estimated according to the analytic expression of pump saturation intensity. The effects of pulse width, gas pressure and path length on the energy absorbed from pump light are studied theoretically. The results can be applied to the analysis of pulsed, optically pumped terahertz lasers.

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An Efficient Pulsed CH3OH Terahertz Laser Pumped by a TEA CO2 Laser

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Chinese Physics Letters 2010年第2期27卷 117-119页

作者：纠智先左都罗苗亮祁春超程祖海 Wuhan National Laboratory for Optoelectronics College of Optoelectronic Science and EngineeringHuazhong University of Science and TechnologyWuhan 430074

An efficient pulsed CH3OH terahertz （THz） laser pumped by a TEA CO2 laser is investigated experimentally. To improve photon conversion efficiency and THz laser energy, two cavity configurations of the TEA CO2 laser, which is external and semi-external, are evaluated. The pump intensities are about 4.7 MW/cm2 and 1.2 MW/cm2, respectively. Higher pump intensity and more stable single lines are obtained in the external cavity. For the 3.8 J pump energy of the 9P（16） transition in the external cavity, the maximum terahertz output energy with 570.5 μm wavelength at 160 Pa is 431 μJ. With a 6 J energy pulse in terms of a semi-external cavity, a 353 μJ terahertz emission （570.5 μm） is produced. The corresponding photon conversion efficiencies are 1.36% and 0.705%, increasing by a factor of about 2.

关键词： Optics quantum optics and lasers

An Efficient Photon Conversion Efficiency Ammonia Terahertz Cavity Laser

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Chinese Physics Letters 2009年第12期26卷 106-109页

作者：祁春超左都罗卢彦兆唐建杨晨光柯林达程祖海 Wuhan National Laboratory for Optoelectronics Wuhan 430074 College of Optoelectronic Science and Engineering Huazhong University of Science and Technology Wuhan 430074

An efficient ammonia terahertz （THz） cavity laser is reported experimentally. Unlike the past design schemes such as hole couplers and freestanding mesh couplers, in our systems the input and output couplers are fabricated by depositing nickel capacitive metallic meshes on ZnSe and high-resistivity silicon substrates. Thus the couplers not only can be constructed as an F-P oscillator but also can be used as sealed windows that are easier to perform the adjustment of alignment with. To enhanceTHz laser output energy and photon conversion efficiency, the dominant factors such as pump intensity and gas pressure are investigated experimentally. Finally, a 1.35mJ terahertz radiation of ammonia laser with 90μm wavelength （3.33THz） operating at 1.09kPa pumped by a 402mJ TEA CO2 laser with 9R （16） line is generated, and photon conversion efficiencies of 6.5% are achieved.

关键词： Optics quantum optics and lasers

High energy optically pumped NH_3 terahertz laser with simple cavity

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Chinese Optics Letters 2010年第4期8卷 411-413页

作者：苗亮左都罗纠智先程祖海祁春超吴君竹 Wuhan National Laboratory for Optoelectronics College of Optoelectronic Science and Engineering Huazhong University of Science and Technology

A high energy pulsed terahertz（THz） laser is studied *** laser cavity simply consists of a quartz glass waveguide,a coated GaAs input window,and a crystal quartz output ***3 is filled in the cavity as gain medium,and pumped by an 8-J line-tunable transversely excited atmospheric（TEA） CO_2 *** 9R（16） transition acts as the pump line,55.6-mJ THz radiation（90μm） is obtained at 730-Pa NH_3 *** corresponding conversion efficiency is 13.54%.Energy and optimal pressure of amplified spontaneous emission and laser oscillation are compared.

关键词： Conversion efficiency Glass lasers High energy physics Infrared lasers Oxide minerals Pulsed laser applications Pulsed lasers Quartz