公开(公告)号：US07450718B2

公开(公告)日：2008-11-11

申请号：US11071696

申请日：2005-03-03

申请人： Jonathan Young ,  Michael J. Lagasse

发明人： Jonathan Young ,  Michael J. Lagasse

IPC分类号： G06F9/00

CPC分类号： H04L9/0852 ,  H04L9/12

摘要： A method of synchronizing the operation of a two-way QKD system by sending a sync signal (SC) in only one direction, namely from one QKD station (ALICE) to the other QKD station (BOB). The one-way transmission greatly reduces the amount of light scattering as compared to two-way sync signal transmission. The method includes phase-locking the sync signal at BOB and dithering the timing of the quantum signals so as to operate the QKD system in three different operating states. The number of detected quantum signals is counted for each state for a given number of detector gating signals. The QKD system is then operated in the state associated with the greatest number of detected quantum signals. This method is rapidly repeated during the operation of the QKD system to compensate for timing errors to maintain the system at or near its optimum operating state. The method allows for only having to adjust the timing of a single timed element—namely, the quantum laser—to compensate for timing variations, rather than having to adjust the timing of all or some of the timed elements in the QKD system.

摘要翻译： 一种通过仅在一个方向（即从一个QKD站（ALICE）到另一个QKD站（BOB））发送同步信号（SC）来同步双向QKD系统的操作的方法。 与双向同步信号传输相比，单向传输大大减少了光散射量。 该方法包括在BOB处对同步信号进行锁相和抖动量子信号的定时，以便在三种不同的工作状态下操作QKD系统。 对于给定数量的检测器门控信号，针对每个状态计数检测到的量子信号的数量。 然后，QKD系统在与最大数量的检测到的量子信号相关联的状态下运行。 该方法在QKD系统的操作期间快速重复以补偿定时误差，以将系统维持在或接近其最佳操作状态。 该方法仅允许调整单个定时元件（即量子激光器）的定时，以补偿定时变化，而不必调整QKD系统中所有或部分定时元件的定时。

公开(公告)号：US20090208220A1

公开(公告)日：2009-08-20

申请号：US12322379

申请日：2009-02-02

申请人： Michael J. Lagasse

发明人： Michael J. Lagasse

IPC分类号： H04B10/00

CPC分类号： H04B10/00 ,  H03K3/42 ,  H04B2210/006

摘要： Systems and methods for generating RF pulses that have a reduced phase error are disclosed. The systems are optical based and thus are highly linear, so that phase errors, including jitter, are significantly reduced as compared to electrical RF pulse generation systems and methods. The optical-based RF pulse generation methods includes generating laser light, imparting an envelope modulation to the laser light, imparting a carrier modulation to the laser light, and detecting the envelope-modulated and carrier-modulated light to form the electrical RF pulse. The electrical RF pulse can then be carried by a cable to an external device.

摘要翻译： 公开了用于产生具有减小的相位误差的RF脉冲的系统和方法。 这些系统是基于光学的，因此是高度线性的，使得与电RF脉冲发生系统和方法相比，包括抖动在内的相位误差显着降低。 基于光的RF脉冲产生方法包括产生激光，向激光施加包络调制，向激光施加载波调制，以及检测包络调制和载波调制的光以形成电RF脉冲。 然后可以通过电缆将电RF脉冲携带到外部设备。

公开(公告)号：US07853020B2

公开(公告)日：2010-12-14

申请号：US11901773

申请日：2007-09-19

申请人： A. Craig Beal ,  Michael J. Lagasse ,  Audrius Berzanskis

发明人： A. Craig Beal ,  Michael J. Lagasse ,  Audrius Berzanskis

IPC分类号： H04L9/08

CPC分类号： H04L9/0858

摘要： Systems and methods for enhanced quantum key distribution (QKD) using an actively compensated QKD system. The method includes exchanging quantum signals between first and second QKD stations and measuring the quantum signal error. An error signal SE representative of the system visibility error is then generated. An error-signal threshold STH that defines a system visibility error limit is then selected. Those qubits measured with the condition SE>STH are called “above-threshold” qubits, while those qubits measured with the condition SE≦STH are called “below-threshold” qubits. Only below-threshold qubits are stored and used to form the final quantum key. This is accomplished by sending a blanking signal SB to the memory unit where the qubits are stored. The blanking signal prevents above-threshold qubits from being stored therein. The raw quantum key so formed has few errors and thus forms a longer final quantum key for a given number of exchanged quantum signals.

摘要翻译： 使用积极补偿的QKD系统来增强量子密钥分配（QKD）的系统和方法。 该方法包括在第一和第二QKD站之间交换量子信号并测量量子信号误差。 然后产生代表系统可见性错误的错误信号SE。 然后选择定义系统可见性错误极限的误差信号阈值STH。 以条件SE> STH测量的量子位称为“高于阈值”量子位，而用条件SE＆nlE; STH测量的量子位称为“低于阈值”量子位。 只有低于阈值的量子位被存储并用于形成最终量子密钥。 这通过将消隐信号SB发送到存储量子位的存储器单元来实现。 消隐信号防止存储高于阈值的量子位。 如此形成的原始量子密钥具有很少的误差，因此对于给定数量的交换量子信号形成更长的最终量子密钥。

公开(公告)号：US20090074192A1

公开(公告)日：2009-03-19

申请号：US11901773

申请日：2007-09-19

申请人： A. Craig Beal ,  Michael J. Lagasse ,  Audrius Berzanskis

发明人： A. Craig Beal ,  Michael J. Lagasse ,  Audrius Berzanskis

IPC分类号： H04L9/08

CPC分类号： H04L9/0858

摘要： Systems and methods for enhanced quantum key distribution (QKD) using an actively compensated QKD system. The method includes exchanging quantum signals between first and second QKD stations and measuring the quantum signal error. An error signal SE representative of the system visibility error is then generated. An error-signal threshold STH that defines a system visibility error limit is then selected. Those qubits measured with the condition SE>STH are called “above-threshold” qubits, while those qubits measured with the condition SE≦STH are called “below-threshold” qubits. Only below-threshold qubits are stored and used to form the final quantum key. This is accomplished by sending a blanking signal SB to the memory unit where the qubits are stored. The blanking signal prevents above-threshold qubits from being stored therein. The raw quantum key so formed has few errors and thus forms a longer final quantum key for a given number of exchanged quantum signals.

摘要翻译： 使用积极补偿的QKD系统来增强量子密钥分配（QKD）的系统和方法。 该方法包括在第一和第二QKD站之间交换量子信号并测量量子信号误差。 然后产生代表系统可见性错误的错误信号SE。 然后选择定义系统可见性错误极限的误差信号阈值STH。 用条件SE> STH测量的量子位称为“高于阈值”量子位，而用条件SE <= STH测量的量子位称为“低于阈值”量子位。 只有低于阈值的量子位被存储并用于形成最终量子密钥。 这通过将消隐信号SB发送到存储量子位的存储器单元来实现。 消隐信号防止存储高于阈值的量子位。 如此形成的原始量子密钥具有很少的误差，因此对于给定数量的交换量子信号形成更长的最终量子密钥。

公开(公告)号：US07529373B2

公开(公告)日：2009-05-05

申请号：US10589419

申请日：2005-03-03

申请人： Jonathan Young ,  Harry Vig ,  Michael J. Lagasse

发明人： Jonathan Young ,  Harry Vig ,  Michael J. Lagasse

IPC分类号： H04L9/00 ,  H04L9/08

CPC分类号： H04B10/70 ,  H04L9/0852

摘要： A method of autocalibrating a quantum key distribution (QKD) system (200) is disclosed. The QKD system includes a laser ((202) that generates photon signals in response to a laser gating signal (S0) from a controller (248). The method includes first performing a laser gate scan (304) to establish the optimum arrival time (TMAX) of the laser gating signal corresponding to an optimum—e.g., a maximum number of photon counts (NMAX)—from a single-photon detector (SPD) unit (216) in the QKD system when exchanging photon signals between encoding stations (Alice and Bob) of the QKD system. Once the optimal laser gating signal arrival time (TMAX) is determined, the laser gate scan is terminated and a laser gate dither process (308) is initiated. The laser dither involves varying the arrival time (T) of the laser gating signal around the optimum value of the arrival time TMAX. The laser gate dither provides minor adjustments to the laser gating signal arrival time to ensure that the SPD unit produces an optimum (e.g., maximum) number of photon counts.

摘要翻译： 公开了一种自动校准量子密钥分发（QKD）系统（200）的方法。 QKD系统包括激光器（202），其响应于来自控制器（248）的激光门控信号（S0）产生光子信号，该方法包括首先执行激光门扫描（304）以建立最佳到达时间（ 当在编码站之间交换光子信号时，QKD系统中的单光子检测器（SPD）单元（216）中的最佳光子计数（NMAX）的最佳数量对应于激光门控信号（TMAX） 和Bob），一旦确定了最佳激光门控信号到达时间（TMAX），终止激光门扫描，开始激光门抖动处理（308），激光抖动涉及改变到达时间（T ）激光门控信号绕到达到时间TMAX的最佳值。激光门抖动对激光门控信号到达时间进行微调，以确保SPD单元产生最佳（例如，最大）数量的光子计数。

公开(公告)号：US07221812B2

公开(公告)日：2007-05-22

申请号：US11052373

申请日：2005-02-07

申请人： Michael J. Lagasse

发明人： Michael J. Lagasse

IPC分类号： G02B6/00 ,  G02B27/10 ,  G02F1/29

CPC分类号： G02B27/1073 ,  G02B27/145

摘要： A bulk-optics assembly for a transmitting/receiving QKD station (BOB1) in a two-way autocompensating QKD system (101) is disclosed. The assembly consists of a first beamsplitter (104) having a high (e.g., 90:10) beamsplitting ratio, a 50:50 beamsplitter (106) and a polarizing beamsplitter (108). The assembly also optionally includes a polarizer (102), and/or a fixed attenuator (FOA), and/or an optional blocking filter (110) downstream of the polarizing beamsplitter. The compact bulk-optics assembly is easier to manufacture than a fiber-based optical system, and is simpler and more compact than prior art bulk-optics assemblies for QKD systems.

摘要翻译： 公开了一种用于双向自动补偿QKD系统（101）中的发送/接收QKD站（BOB1）的体光学组件。 组件由具有高（例如90:10）分束比的第一分束器（104），50:50分束器（106）和偏振分束器（108）组成。 组件还可选地包括偏振器（102）和/或固定衰减器（FOA）和/或偏振分束器下游的可选的阻挡滤光器（110）。 紧凑的体光学组件比基于光纤的光学系统更容易制造，并且比现有技术的用于QKD系统的大容量光学组件更简单和更紧凑。