CN202218230U

CN202218230U - Basic vector automatic adjustment device for quantum communication system

Info

Publication number: CN202218230U
Application number: CN2011202086901U
Authority: CN
Inventors: 张明; 王建宇; 贾建军; 吴金才; 张亮; 杨世骥; 周辉; 江昊; 强佳
Original assignee: Shanghai Institute of Technical Physics of CAS
Current assignee: Shanghai Institute of Technical Physics of CAS
Priority date: 2011-06-21
Filing date: 2011-06-21
Publication date: 2012-05-09
Anticipated expiration: 2021-06-21

Abstract

This patent discloses a basic vector automatic adjustment device for a quantum communication system, which includes a rotating motor assembly, a half-wave plate, a motor controller, a real-time controller and a rotary transformer in the quantum communication system. The real-time controller reads the position of the telescope in real time through the resolver, calculates the deflection angle of the signal light and the rotation angle of the half-wave plate according to the algorithm, generates a control signal and sends it to the motor controller, and the motor controller receives the control signal according to the photoelectric The position of the half-wave plate measured by the encoder controls the motor to rotate the half-wave plate to an appropriate position, and rotates the signal light to an appropriate polarization state, so that the quantum communication system can correctly detect the polarization information of the quantum light through the basis vector. The device solves the problem that the polarization direction of the signal light changes due to the change of the telescope azimuth during tracking in quantum communication, thereby ensuring that the receiving end can correctly detect the polarization state of the signal light under a specific basis vector standard.

Description

Basic vector automatic adjustment device for quantum communication system

技术领域 technical field

本专利涉及自由空间量子通信技术，具体涉及一种用于量子通信系统的基矢自动调节装置，它用于对量子通信中因粗跟踪所造成的信号光的偏振方向变化进行自动调节。 This patent relates to free-space quantum communication technology, in particular to a base vector automatic adjustment device for quantum communication systems, which is used to automatically adjust the polarization direction change of signal light caused by rough tracking in quantum communication. the

技术背景 technical background

空间尺度量子通信中主要是靠具有特定偏振态的光量子传输信息，判断光量子的偏振态需要有统一的标准，本系统中引入一种特定的正交二维坐标系作为判断光子偏振态的标准，并且整个通信系统中用于判断信号光偏振状态的坐标系一致，将该坐标系称为基矢。发射端以基矢作为标准发射带有偏振信息的量子光，接收端接收到量子光后同样以基矢为标准提取量子光的偏振信息。 Space-scale quantum communication mainly relies on light quanta with a specific polarization state to transmit information, and a unified standard is required for judging the polarization state of light quanta. This system introduces a specific orthogonal two-dimensional coordinate system as the standard for judging the polarization state of photons. Moreover, the coordinate system used to judge the polarization state of the signal light in the entire communication system is consistent, and this coordinate system is called a base vector. The transmitting end uses the basis vector as a standard to emit quantum light with polarization information, and the receiving end also uses the basis vector as a standard to extract the polarization information of the quantum light after receiving the quantum light. the

在空间尺度量子通信中，卫星沿着轨道绕地球旋转，不停的向地面接收站发射信号光，地面接收站需要不断调整望远镜姿态以便于捕获卫星传输过来的信号，如图2中I所示。望远镜在捕获信号光时主要有两种姿态变化：俯仰方向旋转和水平方向旋转。如图2中II所示，以地面坐标系为准，垂直地面向上为Z轴，水平方向以右手定则确定X轴与Y轴。规定俯仰方向旋转的角度为俯仰角，由-Z轴向+Z轴方向旋转为正，范围为-90度到90度；水平方向旋转的角度为方位角，以+Z轴为轴向右旋为正，范围为-180度到180度(望远镜实际俯仰角与方位角的范围比较小)。 In space-scale quantum communication, the satellite rotates around the earth along the orbit and continuously transmits signal light to the ground receiving station. The ground receiving station needs to constantly adjust the attitude of the telescope in order to capture the signal transmitted by the satellite, as shown by I in Figure 2 . When the telescope captures signal light, there are two main attitude changes: rotation in the pitch direction and rotation in the horizontal direction. As shown in II in Figure 2, based on the ground coordinate system, the Z axis is vertically upward, and the X axis and Y axis are determined by the right-hand rule in the horizontal direction. It is specified that the angle of rotation in the pitch direction is the pitch angle, and the rotation from the -Z axis to the +Z axis is positive, and the range is -90 degrees to 90 degrees; the angle of rotation in the horizontal direction is the azimuth angle, and the +Z axis is the axis to the right. It is positive, and the range is -180 degrees to 180 degrees (the range of the actual pitch angle and azimuth angle of the telescope is relatively small). the

为了将望远镜捕获到的信号光传输到后光路系统中进行处理，需要在望远镜的旋转臂中安装反射光路，如图3所示，左边为望远镜旋转臂光路图，其中 6为望远镜镜筒、7为望远镜旋转臂、8为入射光线、9为水平反射光线、10为垂直反射光线。由图3可以看出，当望远镜旋转时会影响反射光路中信号光的偏振方向。规定信号光传播的方向为Z轴，基矢坐标垂直于Z轴，并满足右手定则，图中A所表示的X-Y轴为入射光8的基矢坐标。当望远镜的俯仰角变化时，则会引起望远镜水平反射光9的偏振旋转；设望远镜镜筒俯仰角为a，规定沿信号光的传播方向，信号光偏振状态右旋为正，则水平反射光9的偏振方向旋转的角度为a，如图3中B所示，其中虚线表示整个系统的基矢，X-Y轴表示信号光的偏振方向所在的平面旋转状态。当旋转臂带动望远镜水平方向旋转时，则会引起旋转臂垂直向上反射到后光路的信号光产生旋转，如图3中10所示；同样设望远镜镜筒水平方位角为b，同样定义右旋为正，则垂直反射光的偏振方向旋转的角度为b，如图3中C所示。 In order to transmit the signal light captured by the telescope to the rear optical system for processing, it is necessary to install a reflection optical path in the rotating arm of the telescope, as shown in Figure 3, the left is the optical path diagram of the telescope rotating arm, in which 6 is the telescope barrel, 7 8 is the incident ray, 9 is the horizontal reflected ray, and 10 is the vertical reflected ray. It can be seen from Figure 3 that when the telescope rotates, it will affect the polarization direction of the signal light in the reflected light path. It is stipulated that the direction of signal light propagation is the Z axis, and the base vector coordinates are perpendicular to the Z axis, and satisfy the right-hand rule. The X-Y axis represented by A in the figure is the base vector coordinates of the incident light 8 . When the pitch angle of the telescope changes, it will cause the polarization rotation of the horizontally reflected light 9 of the telescope; if the pitch angle of the telescope barrel is a, it is stipulated that along the propagation direction of the signal light, the right-handed polarization state of the signal light is positive, and the horizontally reflected light The rotation angle of the polarization direction of 9 is a, as shown by B in Figure 3, where the dotted line represents the basis vector of the entire system, and the X-Y axis represents the plane rotation state where the polarization direction of the signal light is located. When the rotating arm drives the telescope to rotate in the horizontal direction, it will cause the signal light reflected vertically upward by the rotating arm to the rear optical path to rotate, as shown by 10 in Figure 3; also set the horizontal azimuth angle of the telescope lens barrel as b, and also define the right rotation is positive, then the angle of rotation of the polarization direction of the vertically reflected light is b, as shown in C in Figure 3. the

根据以上分析可以得出：俯仰角a会造成镜筒水平反射光9偏振右旋，方位角b造成旋转臂垂直反射光10偏振右偏。由于镜筒俯仰角与方位角的叠加，旋转臂垂直出射光线的偏振方向相对于入射光线的基矢方向偏转角度为a+b，所以当偏振角为α的信号光进入望远镜后，会经过望远镜镜筒底部的凹面镜汇聚到镜筒中间的反射镜上，经过镜筒反射镜将光线水平反射到旋转臂中的反射光路，如果镜筒的俯仰角a不为零的话，此时水平反射光线的的偏振角与基矢的X轴的夹角就会变化为α+a。当光线进入反射光路时首先需要通过一片凸透镜将光线变为平行光，然后再经过三个平面反射镜反射到后光路。当信号光经过最后一块平面反射镜垂直向上反射到后光路时，如果此时望远镜的方位角b不为零，那么信号光的偏振方向与基矢的X轴夹角就会变为α+a+b，如图3中D所示。 According to the above analysis, it can be concluded that the pitch angle a will cause the 9 polarization of the horizontally reflected light of the lens barrel to be right-handed, and the azimuth b will cause the 10 polarization of the vertically reflected light of the rotating arm to be right-shifted. Due to the superposition of the pitch angle and the azimuth angle of the lens barrel, the polarization direction of the vertical outgoing light of the rotating arm is deflected by a+b relative to the base vector direction of the incident light. Therefore, when the signal light with a polarization angle of α enters the telescope, it will pass through the telescope The concave mirror at the bottom of the lens barrel converges to the reflector in the middle of the lens barrel, and the light is horizontally reflected to the reflection path in the rotating arm through the lens barrel reflector. If the pitch angle a of the lens barrel is not zero, the light is reflected horizontally at this time The angle between the polarization angle and the X-axis of the base vector will change to α+a. When light enters the reflected light path, it first needs to pass through a convex lens to turn the light into parallel light, and then reflect to the rear light path through three flat mirrors. When the signal light is reflected vertically upwards to the rear optical path by the last plane mirror, if the azimuth b of the telescope is not zero at this time, the angle between the polarization direction of the signal light and the X-axis of the base vector will become α+a +b, as shown in D in Figure 3. the

图1量子通信系统5中的量子接收端固定在后光路中，信号光进行检测之前必须将其偏振状态旋转到接收端以基矢标准能够正确检测的偏振状态，这就需要在后光路中增加旋光元件。本系统中采用半波片对信号光偏振进行旋转，当半波片快轴方向与基矢X轴夹角为θ(逆时针方向为正)时，其琼斯矩阵为： The quantum receiving end in the quantum communication system 5 in Fig. 1 is fixed in the rear optical path. Before the signal light is detected, its polarization state must be rotated to a polarization state that can be detected correctly by the base vector standard at the receiving end, which requires the rear optical path Add optical rotators. In this system, the half-wave plate is used to rotate the polarization of the signal light. When the angle between the fast axis direction of the half-wave plate and the X-axis of the base vector is θ (the counterclockwise direction is positive), the Jones matrix is:

$[\begin{matrix} cos cos 22 θ θ,, sin sin 22 θ θ \\ sin sin 22 θ θ,, - - cos cos 22 θ θ \end{matrix}]$

当光矢量与X轴成α角时，其琼斯矩阵为： When the light vector forms an angle α with the X axis, its Jones matrix is:

${E E.}_{α α} = = [\begin{matrix} cos cos α α \\ sin sin α α \end{matrix}]$

当该光矢量透射半波片时，出射光线的琼斯矩阵为： When the light vector is transmitted through the half-wave plate, the Jones matrix of the outgoing light is:

${E E.}_{out out} = = [\begin{matrix} cos cos 22 θ θ,, sin sin 22 θ θ \\ sin sin 22 θ θ,, - - cos cos 22 θ θ \end{matrix}] [\begin{matrix} cos cos α α \\ sin sin α α \end{matrix}] = = [\begin{matrix} cos cos ((22 θ θ - - α α)) \\ sin sin ((22 θ θ - - α α)) \end{matrix}]$

所以透过半波片的出射光线的偏振角由α变化为2θ-α。 Therefore, the polarization angle of the outgoing light passing through the half-wave plate changes from α to 2θ-α. the

根据前面分析，设图3中入射信号光偏振方向与X轴方向夹角为α，则由于望远镜旋转的影响，经过旋转臂反射向后光路的信号光的偏振方向逆时针旋转了(a+b)的角度，即此时信号光与水平方向夹角为α+(a+b)。如果将半波片的快轴方向与基矢X轴方向的夹角设置为

如图4所示，其中角12为半波片与基矢X轴夹角，角13为信号光偏振偏转角度。根据半波片的旋波原理，透射过半波片的信号光偏振角度为： According to the previous analysis, if the angle between the polarization direction of the incident signal light and the X-axis direction in Figure 3 is α, then due to the influence of the telescope rotation, the polarization direction of the signal light reflected by the rotating arm to the rear optical path rotates counterclockwise (a+b ), that is, the angle between the signal light and the horizontal direction is α+(a+b). If the angle between the fast axis direction of the half-wave plate and the X-axis direction of the base vector is set as

As shown in FIG. 4 , the angle 12 is the angle between the half-wave plate and the X-axis of the base vector, and the angle 13 is the polarization deflection angle of the signal light. According to the wave rotation principle of the half-wave plate, the polarization angle of the signal light transmitted through the half-wave plate is:

$22 ((\frac{a a + + b b}{22})) - - [[α α + + ((a a + + b b))]] = = - - α α$

即信号光的偏振角最终由α变化为-α，这样在量子检测端只需将检测出的偏正角度取反就能正确得到信号光的偏振状态。 That is, the polarization angle of the signal light is finally changed from α to -α, so that the polarization state of the signal light can be obtained correctly only by inverting the detected polarization angle at the quantum detection end. the

由于望远镜在通信中需要实时的调整姿态以便于跟踪卫星发射的信号光，所以基矢调节系统也需要实时自动的调整反射到后光路的信号光偏振状态，这就需要引入自动控制系统。如图1所示：旋转电机组件1通过光电编码器可以测得半波片2的旋转位置；旋转变压器5-1可以测得望远镜的旋转位置；所以可以利用实时控制器通过旋转变压器实时读取望远镜的位置；再根据前面所述算法计算出信号光偏转的角度以及半波片需要旋转的角度；然后生成控制信号发送给电机控制器；电机控制器3收到控制信号后根据光电编码器测得的半波片位置，控制电机将半波片旋转到适当位置；从而将信号光旋转到恰当的偏振状态，以便于量子接收端能通过基矢正确检测出量子光的偏振信息。 Since the telescope needs to adjust its attitude in real time in order to track the signal light emitted by the satellite, the base vector adjustment system also needs to automatically adjust the polarization state of the signal light reflected to the rear optical path in real time, which requires the introduction of an automatic control system. As shown in Figure 1: the rotary motor assembly 1 can measure the rotational position of the half-wave plate 2 through the photoelectric encoder; the rotary transformer 5-1 can measure the rotary position of the telescope; so the real-time controller can be used to read in real time through the rotary transformer The position of the telescope; then calculate the angle of signal light deflection and the angle that the half-wave plate needs to rotate according to the algorithm described above; then generate a control signal and send it to the motor controller; after the motor controller 3 receives the control signal, measure according to the photoelectric encoder The position of the half-wave plate is obtained, and the motor is controlled to rotate the half-wave plate to an appropriate position; thereby rotating the signal light to an appropriate polarization state, so that the quantum receiving end can correctly detect the polarization information of the quantum light through the basis vector. the

发明内容 Contents of the invention

本发明针对星地间量子通信中，望远镜镜筒由于跟踪卫星而不停的变换空间角度所造成的信号光旋转，从而使信号接收端以固定的基矢无法正确检测出旋变后的光矢量信息的问题，提供了一种有效的基矢自动调节装置。该装置通过可控的半波片，实时根据旋转变压器的数据来旋转已经改变偏振方向的光矢量，通过一系列变换，使光矢量到达通信终端时能被量子接收端正确的检测出来。解决了星地间量子通信中由于望远镜空间角变化引起反射回路中信号光偏振方向旋转变化，导致接收端无法正确检测量子光偏振状态的问题。 The invention aims at the rotation of the signal light caused by the telescope lens barrel constantly changing the space angle due to tracking the satellite in the inter-satellite quantum communication, so that the signal receiving end cannot correctly detect the rotated light vector with a fixed base vector information problem, an efficient basis vector autoregulator is provided. The device uses a controllable half-wave plate to rotate the light vector that has changed its polarization direction in real time according to the data of the resolver. Through a series of transformations, the light vector can be correctly detected by the quantum receiving end when it reaches the communication terminal. It solves the problem that the polarization direction of the signal light in the reflection loop changes due to the change of the space angle of the telescope in the quantum communication between the satellite and the earth, which leads to the problem that the receiving end cannot correctly detect the polarization state of the quantum light. the

本装置是利用半波片的旋波特性，将已经改变偏振态的信号光旋转到恰当角度，然后再通过一系列变换，从而使量子接收端能通过与量子发射端统一的基矢将信号光正确的检测出来。其中望远镜的空间角度可以通过安装在望远镜镜筒的水平旋转轴和俯仰旋转轴上的旋转变压器读出，半波片的旋转角度则可以通过光电编码器以及电机控制器来控制。 This device uses the rotational wave characteristics of the half-wave plate to rotate the signal light that has changed its polarization state to an appropriate angle, and then through a series of transformations, so that the quantum receiving end can transmit the signal through the same base vector as the quantum transmitting end. The light is correctly detected. The space angle of the telescope can be read by a resolver installed on the horizontal rotation axis and pitch rotation axis of the telescope barrel, and the rotation angle of the half-wave plate can be controlled by a photoelectric encoder and a motor controller. the

装置中设定一种特定的正交二维坐标系作为判断光子偏振态的标准，将该坐标系称为基矢；发射端以基矢为标准发射具有一定偏振状态的量子光，接收端以基矢为标准检测信号光的偏振状态。使用该装置，量子光发射端和接收端可以使用统一的基矢作为光矢量的判断标准。信号光进入望远镜旋转臂反射光路，偏振状态会改变，在到达量子接收端前，通过半波片将量子光的偏振方向旋转到初始偏振方向的负方向，这样在接收端便可以利用预定的基矢检测出信号光的偏振状态，而不用担心由望远镜跟踪卫星所造成的信号光偏振方向的变化。 A specific orthogonal two-dimensional coordinate system is set in the device as a standard for judging the polarization state of photons, and the coordinate system is called the base vector; the transmitting end emits quantum light with a certain polarization state based on the base vector, and the receiving end uses The base vector is the polarization state of the standard detection signal light. Using this device, the quantum light transmitter and receiver can use a unified base vector as the criterion for judging the light vector. When the signal light enters the reflection path of the rotating arm of the telescope, the polarization state will change. Before reaching the quantum receiving end, the polarization direction of the quantum light is rotated to the negative direction of the initial polarization direction through the half-wave plate, so that the predetermined base can be used at the receiving end. It can detect the polarization state of the signal light without worrying about the change of the polarization direction of the signal light caused by the telescope tracking the satellite. the

本专利量子通信基矢自动调节装置的结构如图1所示，其结构包括：旋转电机组件1、半波片2、电机控制器3、实时控制器4和量子通信系统5中的旋转变压器5-1。其中： The structure of the quantum communication base vector automatic adjustment device of this patent is shown in Figure 1, and its structure includes: a rotating motor assembly 1, a half-wave plate 2, a motor controller 3, a real-time controller 4 and a resolver 5 in a quantum communication system 5 -1. in:

1.旋转电机组件1由旋转电机、光电编码器和半波片安装基座组成，半波片2固定在半波片基座上，半波片安装基座通过蜗杆-蜗轮传动副与旋转电机连接；光电编码器安装在旋转电机上，主要负责测量旋转电机组件的旋转位置，其精度要求达到0.1度；旋转电机采用可控的直流电机或者步进电机，反应速度在0.3s以内，旋转电机通过蜗杆-蜗轮传动副带动半波片安装基座旋转，半波片安装基座的旋转精度为0.1度； 1. The rotating motor assembly 1 is composed of a rotating motor, a photoelectric encoder and a half-wave plate mounting base. The half-wave plate 2 is fixed on the half-wave plate base. The half-wave plate mounting base is connected to the rotating motor through the worm-worm gear transmission pair. Connection; the photoelectric encoder is installed on the rotating motor, and is mainly responsible for measuring the rotational position of the rotating motor assembly, and its accuracy is required to reach 0.1 degrees; the rotating motor adopts a controllable DC motor or a stepping motor, and the response speed is within 0.3s. The half-wave plate installation base is driven to rotate through the worm-worm gear transmission pair, and the rotation accuracy of the half-wave plate installation base is 0.1 degrees;

2.半波片2选取量子通信系统5需要信号光波长相应的入/2半波片； 2. The half-wave plate 2 selects the input/2 half-wave plate corresponding to the wavelength of the signal light required by the quantum communication system 5;

3.电机控制器3用来读取光电编码器数据和控制旋转电机，并且具有可编程控制的功能； 3. The motor controller 3 is used to read the data of the photoelectric encoder and control the rotating motor, and has the function of programmable control;

4.实时控制器4采用电脑或者具有浮点运算功能的可编程器件，用来实时读取旋转变压器数据，计算半波片需要旋转角度，控制电机控制器； 4. The real-time controller 4 adopts a computer or a programmable device with floating-point calculation function to read the data of the resolver in real time, calculate the rotation angle required by the half-wave plate, and control the motor controller;

5.旋转变压器5-1是两个旋转变压器，分别安装在光学终端望远镜的俯仰轴和水平轴上，负责读取望远镜水平方位角和俯仰角数据，其测量精度为0.1度。 5. Resolver 5-1 is two resolvers, installed on the pitch axis and horizontal axis of the optical terminal telescope respectively, responsible for reading the telescope's horizontal azimuth and pitch angle data, and its measurement accuracy is 0.1 degrees. the

旋转电机组件1安装在量子通信系统5的望远镜后光路中；半波片2固定在旋转电机组件1上的半波片安装基座中，信号光需要先通过半波片才能到达量子信号接收端；电机控制器3通过数据线连接到旋转电机组件上以便于读取光电编码器数据和控制旋转电机；实时控制器4通过一根数据线连接旋转变压器5-1读取望远镜空间角数据，通过另外一根数据线连接电机控制器3来向电机控制器发送控制信号；旋转变压器5-1分别安装在望远镜水平旋转轴上和俯仰旋转轴上，分别测量望远镜水平方位角和俯仰角数据，并通过数据线将数据传送给实时控制器4。 The rotating motor component 1 is installed in the optical path behind the telescope of the quantum communication system 5; the half-wave plate 2 is fixed in the half-wave plate mounting base on the rotating motor component 1, and the signal light needs to pass through the half-wave plate before reaching the quantum signal receiving end ; The motor controller 3 is connected to the rotating motor assembly by a data line so as to read the photoelectric encoder data and control the rotating motor; the real-time controller 4 is connected to the resolver 5-1 by a data line to read the space angle data of the telescope, through Another data line is connected to the motor controller 3 to send control signals to the motor controller; the resolver 5-1 is respectively installed on the horizontal rotation axis of the telescope and on the pitch rotation axis to measure the horizontal azimuth and pitch angle data of the telescope respectively, and The data is transmitted to the real-time controller 4 through the data line. the

旋转电机组件1通过光电编码器测得半波片2的旋转位置，旋转变压器5-1测得望远镜的旋转位置，利用实时控制器4通过旋转变压器实时读取望远镜的位置；再根据算法计算出信号光偏转的角度以及半波片需要旋转的角度，生成控制信号发送给电机控制器3，电机控制器3收到控制信号后根据光电编码器测得的半波片位置，控制电机将半波片2旋转到适当位置，将信号光旋转到恰当的偏振状态，以便于量子通信系统5能通过基矢正确检测出量子光的偏振信息。 The rotary motor assembly 1 measures the rotational position of the half-wave plate 2 through the photoelectric encoder, and the rotary transformer 5-1 measures the rotational position of the telescope, and uses the real-time controller 4 to read the position of the telescope in real time through the rotary transformer; The deflection angle of the signal light and the angle at which the half-wave plate needs to be rotated generate a control signal and send it to the motor controller 3. After receiving the control signal, the motor controller 3 controls the motor to rotate the half-wave plate according to the position of the half-wave plate measured by the photoelectric encoder. The plate 2 is rotated to a proper position, and the signal light is rotated to a proper polarization state, so that the quantum communication system 5 can correctly detect the polarization information of the quantum light through the basis vector. the

基矢自动调节具体步骤如下： The specific steps of base vector automatic adjustment are as follows:

1.根据检测量子光偏振态以及望远镜镜筒空间角的变化最大速度设定实时控制器4的控制时间间隔t，每隔时间t实时控制器就会向旋转变压器5-1发送一条指令，读取旋转变压器5-1的数据； 1. Set the control time interval t of the real-time controller 4 according to the detection quantum light polarization state and the maximum speed of the change of the space angle of the telescope lens barrel, and the real-time controller will send an instruction to the resolver 5-1 every time t, and read Get the data of resolver 5-1;

2.旋转臂电机通过调整望远镜来实时捕捉信号光，当偏振角为角为α的信号光进入望远镜后，如果望远镜的俯仰角a和水平旋转角b不为零，反射到后光路的信号光偏振方向与基矢的X轴夹角就会变为α+a+b，望远镜的俯仰角a和水平旋转角b可以通过旋转变压器5-1反馈给实时控制器4； 2. The rotating arm motor captures the signal light in real time by adjusting the telescope. When the signal light with a polarization angle of α enters the telescope, if the pitch angle a and the horizontal rotation angle b of the telescope are not zero, the signal light reflected to the rear optical path The angle between the polarization direction and the X-axis of the base vector will become α+a+b, and the pitch angle a and horizontal rotation angle b of the telescope can be fed back to the real-time controller 4 through the rotary transformer 5-1;

3.实时控制器4通过旋转变压器5-1分别读取到望远镜的俯仰角a以及望远镜的水平方位角b，通过信号光偏振角旋转叠加原理计算出信号光偏振角为α+a+b，并根据半波片旋光特性计算出半波片需要旋转的角度

从而生成控制信号，并把控制信号发送给电机控制器3； 3. The real-time controller 4 respectively reads the pitch angle a of the telescope and the horizontal azimuth b of the telescope through the rotary transformer 5-1, and calculates the polarization angle of the signal light as α+a+b through the principle of rotation and superposition of the polarization angle of the signal light, And calculate the angle that the half-wave plate needs to rotate according to the optical rotation characteristics of the half-wave plate

Thereby generating a control signal, and sending the control signal to the motor controller 3;

4.电机控制器3接收到控制信号，启动旋转电机组件1中的旋转电机旋转半波片2，并不断的通过光电编码器测量半波片的角度，当半波片旋转到快轴方向与基矢X轴夹角为

时便停止旋转，等待实时控制器4的下一条指令； 4. The motor controller 3 receives the control signal, starts the rotating motor in the rotating motor assembly 1 to rotate the half-wave plate 2, and continuously measures the angle of the half-wave plate through the photoelectric encoder. When the half-wave plate rotates to the direction of the fast axis and The angle between the base vector and the X-axis is

When just stop rotating, wait for the next instruction of real-time controller 4;

5.反射到后光路的信号光偏振角为α+a+b，信号光到达量子接收器之前会先透射过半波片2，由于半波片的旋光特性，信号光的偏振角会变为-α； 5. The polarization angle of the signal light reflected to the rear optical path is α+a+b. The signal light will first pass through the half-wave plate 2 before reaching the quantum receiver. Due to the optical rotation characteristics of the half-wave plate, the polarization angle of the signal light will become - α;

6.量子接收器接收到信号光，以预设的基矢为标准检测出量子光的偏振角为-α，并将该角度取反便得到入射光的偏振角度α，以此便完成了量子通信系统的基矢自动调节，使偏振状态改变了的信号光能够最终被正确的检测出来。 6. The quantum receiver receives the signal light, detects that the polarization angle of the quantum light is -α based on the preset base vector, and inverts the angle to obtain the polarization angle α of the incident light, thus completing the quantum The base vector of the communication system is automatically adjusted, so that the signal light whose polarization state has changed can be finally detected correctly. the

本专利的有益效果在于：量子通信系统中采用基矢自动调节控制系统可以有效的解决望远镜空间方位变化所造成光路中信号光的偏振变化，能够实时有效的将信号光的偏正方向旋转到恰当的角度，从而使量子接收端能够正确的检测出信号光偏振状态，保证了量子通信顺利的进行。 The beneficial effect of this patent is that: the use of the base vector automatic adjustment control system in the quantum communication system can effectively solve the polarization change of the signal light in the optical path caused by the change of the space orientation of the telescope, and can effectively rotate the polarization direction of the signal light to an appropriate position in real time. angle, so that the quantum receiving end can correctly detect the polarization state of the signal light, ensuring the smooth progress of quantum communication. the

附图说明 Description of drawings

图1为基矢自动调节装置结构图，图中： Figure 1 is a structural diagram of the base vector automatic adjustment device, in the figure:

1.旋转电机组件 2.半波片 3.电机控制器 1. Rotating motor assembly 2. Half-wave plate 3. Motor controller

4.实时控制器 5.量子通信系统 5-1.旋转变压器。 4. Real-time controller 5. Quantum communication system 5-1. Resolver. the

图2为望远镜空间角度说明图示：图中： Figure 2 is a diagram illustrating the space angle of the telescope: in the figure:

I表示望远镜跟踪卫星的空间示意图； I represents the spatial schematic diagram of the telescope tracking the satellite;

II表示望远镜空间角度坐标图。 II represents the space angle coordinate diagram of the telescope. the

图3为望远镜旋转所造成的反射光路信号光旋转变化的图示，图中： Figure 3 is a schematic diagram of the rotation change of the reflected light path signal light caused by the rotation of the telescope, in the figure:

6.望远镜 7.旋转臂 8.入射光线 6. Telescope 7. Rotating arm 8. Incident light

9.水平反射光线 10.垂直反射光线 9. Horizontal reflected light 10. Vertical reflected light

A.入射光线基矢坐标 B.水平反射光偏振旋转角度 A. The base vector coordinates of the incident light B. The polarization rotation angle of the horizontal reflected light

C.垂直反射光偏振旋转角度 D.反射光路偏振总旋转角度。 C. Vertical reflected light polarization rotation angle D. Reflected light path polarization total rotation angle. the

图4为半波片放置位置示意图。 Figure 4 is a schematic diagram of the placement position of the half-wave plate. the

图5为基矢自动调节方法程序流程图。 Fig. 5 is a flow chart of the program of the base vector automatic adjustment method. the

具体实施方式 Detailed ways

整个可用于量子通信基矢自动调节系统的实例系统如图1所示：旋转电机组件1采用THORLABS公司生产的旋转电机组件PRM1-Z7，其外观尺寸68mm，其半波片基座内径为27mm；该旋转电机组件包含精度为0.1度的光电编码器和反应速度为0.2秒的直流电机，直流电机采用螺纹杆连接到旋转组件的半波片基座上，半波片固定到旋转电机组件的半波片基座上，通过直流电机带动旋转；电机控制器3采用与旋转电机组件配套的THORLABS公司生产的APT直流电机伺服控制器TDC001，该电机控制器能够通过THORLABS公司提供的APT系列控制程序进行编程控制；该实例系统中采用850nm的激光作为信号光，所以半波片采用800至900nm波段的半波片，将其打磨成直径为26mm的圆形，固定到旋转电机组件PRM1-Z7上，并安装到量子通信系统5的后光路中；旋转变压器5-1采用定制的旋转变压器，测量精度能达到0.01度，所以该实例系统的基矢调节静止精度能达到0.1度；实时控制器4采用电脑来实现，通中控电路获得旋转变压器数据，通过串行口连接电机控制器，在电脑上编写控制台程序来实时进行数据的获取，计算，以及电机指令的发送。该实例系统中的电机控制器TDC001，可以通过THORLABS公司提供的APT 系列控制程序进行编程控制。主要用到两个APT软件的ActiveX控件：MG17Motor和MG17Logger，其中MG17Motor控件为电机控制控件，MG17Logger为电机指令日志控件。通过调用MG17Motor控件中的函数可以实现对电机运行的控制以及读取旋转组件旋转的位置，而MG17Logger主要功能是显示对APT直流电机伺服控制器发送的指令。 The entire example system that can be used for the quantum communication base vector automatic adjustment system is shown in Figure 1: the rotating motor component 1 adopts the rotating motor component PRM1-Z7 produced by THORLABS company, its appearance size is 68mm, and the inner diameter of the half-wave plate base is 27mm; The rotating motor assembly includes a photoelectric encoder with an accuracy of 0.1 degrees and a DC motor with a response speed of 0.2 seconds. The DC motor is connected to the base of the half-wave plate of the rotating assembly with a threaded rod, and the half-wave plate is fixed to the half-wave plate of the rotating motor assembly. On the base of the wave plate, the rotation is driven by a DC motor; the motor controller 3 adopts the APT DC motor servo controller TDC001 produced by THORLABS, which is matched with the rotating motor assembly, and the motor controller can be controlled by the APT series control program provided by THORLABS. Programming control; in this example system, 850nm laser is used as the signal light, so the half-wave plate adopts the half-wave plate in the 800-900nm band, and it is polished into a circle with a diameter of 26mm, and fixed on the rotating motor assembly PRM1-Z7. and installed in the rear optical path of the quantum communication system 5; the resolver 5-1 adopts a customized resolver, and the measurement accuracy can reach 0.01 degrees, so the static accuracy of the base vector adjustment of the example system can reach 0.1 degrees; the real-time controller 4 adopts Computer to achieve, through the central control circuit to obtain the resolver data, connect the motor controller through the serial port, write a console program on the computer to obtain data, calculate, and send motor commands in real time. The motor controller TDC001 in this example system can be programmed and controlled by the APT series control program provided by THORLABS. Two ActiveX controls of APT software are mainly used: MG17Motor and MG17Logger, among which MG17Motor is a motor control control, and MG17Logger is a motor command log control. By calling the functions in the MG17Motor control, the control of the motor operation and the reading of the rotating position of the rotating component can be realized, and the main function of the MG17Logger is to display the instructions sent to the APT DC motor servo controller. the

旋转电机组件PRM1-Z7自带有游标刻度盘，游标刻度盘精度为0.1度。其光电编码器采用触点归零的方法，断电后重新启动光电编码器读数为零。所以要使光电编码器读数为绝对位置的话，必须每次启动时使电机绝对归零。该基矢自动调节系统实例软件采用C++编程，编程时需要添加MG17Motor控件，首先要将控件属性中的硬件序列号改为直流电机控制器TDC001的硬件序列号，启动程序时通过控件指令startctrl()来启动电机控制器。实例中采用双线程的编程方式，主线程主要负责实时读取旋转变压器数据，并且进行数据计算转换，然后向直流电机控制器发送指令。启动TDC后会触发一个子线程，该子线程主要负责不断向旋转电机组件读取半波片的绝对位置并显示出来。程序流程图如图5所示。 The rotating motor assembly PRM1-Z7 has its own vernier dial, and the accuracy of the vernier dial is 0.1 degrees. Its photoelectric encoder adopts the method of contact zero return, and the reading of the photoelectric encoder is zero after restarting after power failure. Therefore, if the photoelectric encoder reading is an absolute position, the motor must be absolutely reset to zero every time it is started. The example software of the base vector automatic adjustment system adopts C++ programming. When programming, the MG17Motor control needs to be added. First, the hardware serial number in the control property must be changed to the hardware serial number of the DC motor controller TDC001. When starting the program, the control command startctrl() is used. to start the motor controller. In the example, a dual-thread programming method is adopted. The main thread is mainly responsible for reading the resolver data in real time, performing data calculation and conversion, and then sending instructions to the DC motor controller. After starting the TDC, a sub-thread is triggered, which is mainly responsible for continuously reading the absolute position of the half-wave plate from the rotating motor assembly and displaying it. The program flow chart is shown in Figure 5. the

以下结合图1来进一步阐述本发明能够进行基矢自动调节的具体实施步骤： Below in conjunction with Fig. 1, further set forth the specific implementation steps that the present invention can carry out base vector automatic adjustment:

1.检测量子光偏振态的精度要求为±0.5度，而该实例方案中望远镜镜筒空间角的变化速度最大为0.2度/秒，所以可以在电脑上将控制台的控制时间间隔设置为1s，由于实时控制时可以忽略旋转组件的0.2秒延时，基矢调节系统实时控制精度能达到0.3度。控制台程序每隔1s会向旋转变压器5-1发送一条指令，读取旋转变压器5-1的数据； 1. The accuracy of detecting the polarization state of quantum light is required to be ±0.5 degrees, and the maximum change speed of the space angle of the telescope lens barrel in this example scheme is 0.2 degrees/second, so the control time interval of the console can be set to 1s on the computer , because the 0.2-second delay of the rotating component can be ignored during real-time control, the real-time control accuracy of the base vector adjustment system can reach 0.3 degrees. The console program will send an instruction to the resolver 5-1 every 1s to read the data of the resolver 5-1;

2.本实验中我们采用波长为850nm的45度偏振光作为信号光，实验时某时刻俯仰轴旋转变压器测得望远镜的俯仰角为8.93度，水平轴旋转变压器测得望远镜的方位角为12.46度。当信号光通过旋转臂反射光路时，在后光路测不到45度偏振光，说明信号光偏振方向已经改变； 2. In this experiment, we use 45-degree polarized light with a wavelength of 850nm as the signal light. At a certain moment during the experiment, the pitch angle of the telescope measured by the pitch axis rotary transformer is 8.93 degrees, and the azimuth angle of the telescope measured by the horizontal axis rotary transformer is 12.46 degrees. . When the signal light passes through the rotating arm and reflects the optical path, no 45-degree polarized light can be detected in the rear optical path, indicating that the polarization direction of the signal light has changed;

3.控制台程序通过旋转变压器5-1分别读取到望远镜的俯仰角8.93度以及望远镜的方位角12.46度，计算出半波片需要旋转的角度为10.695度，从而生成控制信号，并把控制信号发送给电机控制器3(APT直流电机伺服控制器TDC001)； 3. The console program reads the pitch angle of the telescope at 8.93 degrees and the azimuth angle of the telescope at 12.46 degrees through the resolver 5-1, and calculates that the half-wave plate needs to be rotated at an angle of 10.695 degrees, thereby generating a control signal and turning the control The signal is sent to the motor controller 3 (APT DC motor servo controller TDC001);

4.电机控制器3接收到控制信号，启动旋转电机组件PRM1-Z7中的电机1旋转半波片2，并不断的通过光电编码器4测量半波片的角度，当半波片旋转到其快轴方向与基矢X轴夹角为10.695度时便停止转动，等待实时控制器4的下一条指令； 4. The motor controller 3 receives the control signal, starts the motor 1 in the rotating motor assembly PRM1-Z7 to rotate the half-wave plate 2, and continuously measures the angle of the half-wave plate through the photoelectric encoder 4, when the half-wave plate rotates to its When the angle between the direction of the fast axis and the X-axis of the base vector is 10.695 degrees, it stops rotating and waits for the next instruction from the real-time controller 4;

5.当已经改变了偏振方向的信号光透射过半波片后，在量子接收器上，以预设的基矢为标准，能够检测到偏振角为135度的信号光。这说明了偏振角为45度的信号光经过反射光路的旋转变化后再经过半波片，其偏振角度变成了-45度，即135度，在量子接收端将测得的偏振光取反，便得到了45度偏振光。以此便完成了量子通信系统的基矢自动调节，使偏振状态改变了的信号光能够最终被正确的检测出来。 5. After the signal light whose polarization direction has been changed is transmitted through the half-wave plate, the signal light with a polarization angle of 135 degrees can be detected on the quantum receiver with the preset base vector as the standard. This shows that the signal light with a polarization angle of 45 degrees passes through the half-wave plate after the rotation of the reflected light path, and its polarization angle becomes -45 degrees, that is, 135 degrees, and the measured polarized light is reversed at the quantum receiving end , 45-degree polarized light is obtained. In this way, the automatic adjustment of the basis vector of the quantum communication system is completed, so that the signal light whose polarization state has changed can be finally detected correctly. the

Claims

1. A basic vector automatic adjustment device for a quantum communication system, which includes a rotating motor assembly (1), a half-wave plate (2), a motor controller (3), a real-time controller (4) and a quantum communication system ( 5) The rotary transformer (5-1), characterized in that:

The rotating motor assembly (1) is composed of a rotating motor, a photoelectric encoder and a half-wave plate mounting base , and the half-wave plate mounting base is connected to the rotating motor through a worm-worm gear transmission pair, and is responsible for measuring the rotational position of the rotating motor assembly. The photoelectric encoder is installed on the rotating motor, and its accuracy reaches 0.1 degrees. The rotating motor adopts a controllable DC motor or a stepping motor, and the response speed is better than 0.3 seconds. The rotating motor drives the half-wave plate installation base through the worm-worm gear transmission pair. Rotation, the rotation accuracy of the half-wave plate mounting base is 0.1 degrees;

The rotary transformer (5-1) is two rotary transformers, which are respectively installed on the pitch axis and the horizontal axis of the telescope in the quantum communication system (5), and are used to read the horizontal azimuth and pitch angle data of the telescope. is 0.1 degrees;

The rotating motor assembly (1) is installed in the rear optical path of the telescope in the quantum communication system (5), the half-wave plate (2) is installed on the half-wave plate installation base in the rotating motor assembly (1), and the motor controller (3 ) is connected to the rotating motor assembly through a data line in order to read the photoelectric encoder data and control the rotating motor. The real-time controller (4) is connected to the resolver (5-1) through a data line to read the space angle data of the telescope. Another data cable is connected to the motor controller (3) to send control signals to the motor controller;

The rotating motor assembly (1) measures the rotational position of the half-wave plate (2) through the photoelectric encoder, the resolver (5-1) measures the rotational position of the telescope, and uses the real-time controller (4) to read the telescope in real time through the resolver Then calculate the deflection angle of the signal light and the rotation angle of the half-wave plate according to the algorithm, generate a control signal and send it to the motor controller (3), and the motor controller (3) receives the control signal according to the photoelectric encoder. The position of the half-wave plate is obtained, and the motor is controlled to rotate the half-wave plate (2) to an appropriate position, so that the signal light is rotated to an appropriate polarization state, so that the quantum communication system (5) can correctly detect the polarization of the quantum light through the basis vector information.

2. A base vector automatic adjustment device for a quantum communication system according to claim 1, characterized in that: said real-time controller (4) adopts a computer or a programmable device with a floating point operation function.