WO2020192269A1 - 一种保偏光纤主轴差分延时的测量装置 - Google Patents

一种保偏光纤主轴差分延时的测量装置 Download PDF

Info

Publication number
WO2020192269A1
WO2020192269A1 PCT/CN2020/073568 CN2020073568W WO2020192269A1 WO 2020192269 A1 WO2020192269 A1 WO 2020192269A1 CN 2020073568 W CN2020073568 W CN 2020073568W WO 2020192269 A1 WO2020192269 A1 WO 2020192269A1
Authority
WO
WIPO (PCT)
Prior art keywords
polarization
maintaining fiber
fiber
maintaining
signal
Prior art date
Application number
PCT/CN2020/073568
Other languages
English (en)
French (fr)
Inventor
金晓峰
秦东林
张程慧
金向东
余显斌
郑史烈
章献民
丛波
Original Assignee
浙江大学
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by 浙江大学 filed Critical 浙江大学
Priority to JP2021514965A priority Critical patent/JP7086335B2/ja
Publication of WO2020192269A1 publication Critical patent/WO2020192269A1/zh
Priority to US17/194,290 priority patent/US11159233B2/en

Links

Images

Classifications

    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04B—TRANSMISSION
    • H04B10/00—Transmission systems employing electromagnetic waves other than radio-waves, e.g. infrared, visible or ultraviolet light, or employing corpuscular radiation, e.g. quantum communication
    • H04B10/07—Arrangements for monitoring or testing transmission systems; Arrangements for fault measurement of transmission systems
    • H04B10/075—Arrangements for monitoring or testing transmission systems; Arrangements for fault measurement of transmission systems using an in-service signal
    • H04B10/079—Arrangements for monitoring or testing transmission systems; Arrangements for fault measurement of transmission systems using an in-service signal using measurements of the data signal
    • H04B10/0795—Performance monitoring; Measurement of transmission parameters
    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04B—TRANSMISSION
    • H04B10/00—Transmission systems employing electromagnetic waves other than radio-waves, e.g. infrared, visible or ultraviolet light, or employing corpuscular radiation, e.g. quantum communication
    • H04B10/07—Arrangements for monitoring or testing transmission systems; Arrangements for fault measurement of transmission systems
    • H04B10/073—Arrangements for monitoring or testing transmission systems; Arrangements for fault measurement of transmission systems using an out-of-service signal
    • H04B10/0731—Testing or characterisation of optical devices, e.g. amplifiers
    • G—PHYSICS
    • G01—MEASURING; TESTING
    • G01M—TESTING STATIC OR DYNAMIC BALANCE OF MACHINES OR STRUCTURES; TESTING OF STRUCTURES OR APPARATUS, NOT OTHERWISE PROVIDED FOR
    • G01M11/00—Testing of optical apparatus; Testing structures by optical methods not otherwise provided for
    • G01M11/30—Testing of optical devices, constituted by fibre optics or optical waveguides
    • G01M11/33—Testing of optical devices, constituted by fibre optics or optical waveguides with a light emitter being disposed at one fibre or waveguide end-face, and a light receiver at the other end-face
    • G01M11/331—Testing of optical devices, constituted by fibre optics or optical waveguides with a light emitter being disposed at one fibre or waveguide end-face, and a light receiver at the other end-face by using interferometer
    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04B—TRANSMISSION
    • H04B10/00—Transmission systems employing electromagnetic waves other than radio-waves, e.g. infrared, visible or ultraviolet light, or employing corpuscular radiation, e.g. quantum communication
    • H04B10/25—Arrangements specific to fibre transmission
    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04B—TRANSMISSION
    • H04B10/00—Transmission systems employing electromagnetic waves other than radio-waves, e.g. infrared, visible or ultraviolet light, or employing corpuscular radiation, e.g. quantum communication
    • H04B10/50—Transmitters
    • H04B10/501—Structural aspects
    • H04B10/503—Laser transmitters
    • G—PHYSICS
    • G02—OPTICS
    • G02B—OPTICAL ELEMENTS, SYSTEMS OR APPARATUS
    • G02B6/00—Light guides; Structural details of arrangements comprising light guides and other optical elements, e.g. couplings
    • G02B6/02—Optical fibres with cladding with or without a coating
    • G02B6/024—Optical fibres with cladding with or without a coating with polarisation maintaining properties

Definitions

  • the invention belongs to the field of optical fiber delay measurement, and in particular relates to a measurement device for polarization-maintaining optical fiber spindle differential delay.
  • Polarization maintaining fiber has a wide range of applications in the field of optical fiber communication sensing. It can be used as a transmission element or a sensing element; as a transmission element, it shows good polarization maintaining ability; as a sensing element, it is widely used Distributed stress sensors, fiber optic gyroscopes, fiber optic current transformers and other fiber optic sensing fields are of great significance to study its transmission and sensing characteristics, and their transmission and sensing characteristics are usually expressed as changes in delay.
  • optical fiber testing In optical fiber testing, optical cable laying, fault checking, etc., the measurement of optical fiber delay will be involved. In various optical fiber experiments and projects, the measurement of optical fiber delay will also be involved. It can be said that accurate optical fiber delay measurement is extremely important in almost all optical fiber communication and optical fiber sensing systems.
  • OTD optical time domain reflection principle
  • OCR low coherent reflection principle
  • OFDR optical frequency domain reflection measurement principle
  • OTDR is widely used in the field of optical fiber network communication to measure the length of optical fiber, detect the position of the optical cable breakpoint, etc.
  • the test accuracy can only reach the microsecond level.
  • OLCR has high test accuracy, the accuracy can reach femtosecond level, and the structure is simple, which is convenient for making portable instruments.
  • the dynamic range of OLCR is relatively small, and the maximum measurement range is only a few centimeters.
  • the polarization states reflected by the two arms of the interferometer must be matched, otherwise it will affect the accuracy of OLCR measurement.
  • the measurement accuracy of OFDR is higher than that of OTDR, which can reach the order of picoseconds; the measurement range is larger than OLCR, up to several kilometers, which has higher practicability.
  • this method requires a fixed-length optical fiber as the reference optical path, which is susceptible to the influence of temperature and reduces the measurement accuracy.
  • the present invention provides a measuring device for the differential delay of the main axis of the polarization maintaining fiber.
  • the measuring device can reach the measurement accuracy of the picosecond level and the dynamic range of the kilometer level.
  • a measuring device for the differential delay of a polarization-maintaining fiber spindle which includes a polarization-maintaining fiber Sagnac interferometer, a signal generator, a microwave detector, and a microprocessor, in which:
  • the polarization-maintaining fiber Sagnac interferometer includes a laser, a photoelectric modulator, and a polarization-maintaining fiber coupler connected in sequence, and also includes an optical fiber interface J1 and an optical fiber interface J2 that are arranged at the two output ends of the polarization-maintaining fiber coupler.
  • the other light output from the fast axis is coupled to the slow axis of the polarization-maintaining fiber under test via the fiber interface J2.
  • the two beams of light on different axes propagate in opposite directions, and the light on the fast axis of the polarization-maintaining fiber under test propagates to the test.
  • the other end of the polarization-maintaining fiber is coupled to the slow axis of the polarization-maintaining fiber coupler through the fiber interface J2, and the light on the slow axis of the polarization-maintaining fiber to be tested propagates to the other end of the polarization-maintaining fiber to be tested and the propagation does not change through the fiber interface J1.
  • the axis enters the slow axis of the polarization-maintaining fiber coupler, the two beams are superimposed and output, and the optical signal is converted into an electrical signal by a photodetector;
  • the signal generator generates a frequency sweeping radio frequency signal, which is modulated onto an optical signal by a photoelectric modulator;
  • the microwave detector is arranged at the output end of the photodetector and is used to detect the power of the radio frequency signal output by the photodetector;
  • the microcontroller is connected to the microwave detector, and is used for calculating the optical delay generated by the polarization maintaining fiber according to the output signal of the microwave detector.
  • the microcontroller calculates and obtains the differential delay of the polarization maintaining fiber spindle according to the following formula:
  • the device uses the different propagation constants of light in the fast axis and slow axis of the polarization-maintaining fiber to produce a delay difference to measure the length of the fiber under test.
  • the structure of the Sagnac interferometer is adopted, and the reference optical path is reduced. The influence of temperature on measurement accuracy.
  • the time delay measurement method based on microwave photon technology it can reach the measurement accuracy of the picosecond level and the dynamic range of the kilometer level.
  • Fig. 1 is a system schematic diagram of a measuring device for a polarization-maintaining optical fiber spindle differential delay according to the present invention
  • Figure 2 is a schematic diagram of the structure of a polarization maintaining fiber
  • Figure 3 is a schematic diagram of the structure of the optical fiber interface, in which Figure 3 (a) is the connection mode that the optical fiber interface J2 must ensure; Figure 3 (b) is the connection mode that the optical fiber interface J1 must ensure.
  • the measurement device for the differential delay of the polarization maintaining fiber spindle includes: a laser (DFB) 1, a signal generator (Signal Source) 2, a photoelectric modulator (MZM) 3, and a polarization maintaining fiber coupler (OC)4, fiber interface J1, fiber interface J2, polarization-maintaining fiber 5 to be tested, photodetector (PD) 6, microwave detector (Radio Detector) 7 and microcontroller (MCU) 8.
  • a laser DFB
  • Signal Generator Signal Generator
  • MZM photoelectric modulator
  • OC polarization maintaining fiber coupler
  • the laser 1, the photoelectric modulator 3, the polarization-maintaining fiber coupler 4, the fiber interface J1, the fiber interface J2, the photodetector 6, and the polarization-maintaining fiber 5 to be tested constitute a polarization-maintaining fiber Saguenaik interferometer.
  • the polarization-maintaining fiber 5 to be tested has two transmission axes, one is a fast axis, and the other is a slow axis perpendicular to the fast draw.
  • the fiber interface J1 and the fiber interface J2 are used to connect the polarization-maintaining fiber coupler 4 and the polarization-maintaining fiber 5 to be tested.
  • the fiber interface J1 ensures that the fast axis and the fast axis of the two sections of fiber to be connected are aligned, and the slow axis and the slow axis are aligned.
  • the fiber interface J2 ensures that the fast axis and the slow axis of the two sections of fiber to be connected are aligned, and the slow axis and the fast axis are aligned.
  • the laser 1 uses a broad-spectrum light source with a coherence length of less than 30 um, and its coherence length is much smaller than the optical path difference caused by the different propagation constants of the fast and slow axes of the polarization-maintaining fiber. Also, the laser 1 emits linearly polarized light.
  • the polarization-maintaining fiber coupler 4 is a 2 ⁇ 2 3dB polarization-maintaining fiber coupler, and the polarization-maintaining fiber coupler 4 is connected to the two lengths of the polarization-maintaining fiber of the fiber interface J1 and the fiber interface J2.
  • the low-coherence linearly polarized light emitted by the laser 1 is carried by the photoelectric modulator 3 with a radio frequency signal, and is divided into two outputs by the polarization maintaining fiber polarization maintaining fiber coupler 4.
  • the light output along the fast axis at port b of the polarization-maintaining fiber coupler enters the polarization-maintaining fiber 5 under test through the fiber interface J1 and still propagates along the fast axis; the other output from port c of the polarization-maintaining fiber coupler along the fast axis
  • One path of light is coupled to the slow axis of the polarization-maintaining fiber 5 to be tested via the fiber interface J2, and the two beams of light on different axes propagate in opposite directions.
  • the light on the fast axis of the polarization-maintaining fiber 5 to be tested propagates to the other end of the polarization-maintaining fiber 5 to be tested, it is coupled to the slow axis of the polarization-maintaining fiber coupler 4 through the fiber interface J2, and the slow axis of the polarization-maintaining fiber 5 to be tested
  • the light from above propagates to the other end of the polarization-maintaining fiber 5 to be measured and enters the slow axis of the polarization-maintaining fiber coupler 4 through the fiber interface J1 without changing the propagation axis.
  • the two beams are superimposed and output, and the optical signal is converted into an electrical signal by the photodetector 6 .
  • a group of sweep frequency signals generated by the signal generator 2 are modulated onto the light and enter the polarization-maintaining fiber Sagnac interferometer. Because the propagation constants of the fast and slow axes of the polarization-maintaining fiber to be measured are different, when it reaches the output end There is a delay difference between the light on the two axes, the superimposed output optical signal is converted into an electrical signal by the photodetector, and its amplitude will carry the delay information, which is calculated by the microwave detector 7 and the microcontroller 8 to generate the polarization maintaining fiber 6 to be measured The light delay.
  • the working principle of the measuring device for the differential delay of the polarization maintaining fiber spindle is as follows:
  • the radio frequency signal generated by the signal generator 2 can be expressed as:
  • the bias voltage applied to the photoelectric modulator is:
  • the first part of equation (3) is the phase change produced by the DC bias, and the second part is the phase change produced by the modulation signal.
  • the bias point of the photoelectric modulator should be placed at the half-wave voltage, namely
  • the gain of the first-order electrical signal used in the product can be maximized, and the high-order harmonic signals can be well suppressed.
  • the expression of the microwave modulated laser at the output end of the photoelectric modulator is:
  • the optical signals in the fast axis and slow axis of the polarization maintaining fiber can be expressed as:
  • the laser is a low-coherence light source, it satisfies the conditions:
  • the output signal of the photodetector is amplified and then input to the detection detector to obtain the output signal:
  • the value is related. As long as the two adjacent frequency points f RF0 and f RF1 where Vout is 0 are measured, the delay amount can be obtained:
  • the method and device for measuring the differential delay of the main axis of the polarization-maintaining fiber uses the difference in the propagation constants of the light in the fast axis and the slow axis of the polarization-maintaining fiber to produce a delay difference to measure the length of the fiber under test, and adopts Sagnac interference
  • the structure of the instrument eliminates the need for a reference optical path, which reduces the influence of temperature on measurement accuracy.
  • the time delay measurement method based on microwave photonic technology it can reach the measurement accuracy of the picosecond level and the dynamic range of the kilometer level.

Landscapes

  • Physics & Mathematics (AREA)
  • Electromagnetism (AREA)
  • Engineering & Computer Science (AREA)
  • Computer Networks & Wireless Communication (AREA)
  • Signal Processing (AREA)
  • Optics & Photonics (AREA)
  • General Physics & Mathematics (AREA)
  • Chemical & Material Sciences (AREA)
  • Analytical Chemistry (AREA)
  • Optical Communication System (AREA)
  • Optical Modulation, Optical Deflection, Nonlinear Optics, Optical Demodulation, Optical Logic Elements (AREA)
  • Gyroscopes (AREA)

Abstract

本发明公开了一种保偏光纤主轴差分延时的测量装置，包括保偏光纤萨格奈克干涉仪、信号发生器，微波检波器，微处理器，其中：保偏光纤萨格奈克干涉仪包括依次连接的激光器、光电调制器、保偏光纤耦合器、设置在保偏光纤耦合器输出端的光纤接口J1、J2，设置在光纤接口J1、J2之间的待测保偏光纤，以及设置在保偏光纤耦合器另一输出端的光电探测器；信号发生器产生扫频射频信号，并被光电调制器调制到光信号上；微波检波器用于检测光电探测器输出的射频信号的功率；微控制器与微波检波器连接，用于根据微波检波器的输出信号计算保偏光纤产生的光延时。该测量装置可以达到皮秒量级的测量精度和千米级的动态范围。

Description

一种保偏光纤主轴差分延时的测量装置 技术领域
本发明属于光纤延时测量领域，具体涉及一种保偏光纤主轴差分延时的测量装置。
背景技术
保偏光纤在光纤通信传感领域有着广泛的运用，它既可以当做传输元件，也可以成为传感元件；作为传输元件，它表现出良好的偏振保持能力；作为传感元件，它广泛运用于分布式应力传感器、光纤陀螺仪、光纤电流互感器等光纤传感领域，研究它的传输、传感特性有着重要的意义，而其传输、传感特性通常表现为延时量的变化。
在光纤测试、光缆铺设、故障检查等各方面，都会涉及到光纤延时的测量在各类光纤实验以及工程中，也会涉及到光纤延时的测量。可以说，准确的光纤延时的测量在几乎所有的光纤通信以及光纤传感系统中都极为重要。
传统的光纤延时测量方法有光时域反射原理(OTDR)，低同调反射原理(OLCR)和光频域反射测量原理(OFDR)等。
OTDR广泛应用到光纤网络通信领域来测量光纤长度，检测光缆断点位置等，但是由于方法本身误差的影响，测试精度只能达到微秒级别。
OLCR测试精度高，精度可达飞秒级别，而且结构简单，方便制成便携仪器。但是OLCR的动态范围比较小，最大的测量范围只有几厘米，同时要求干涉仪两臂反射回来的偏振状态要匹配，否则会影响OLCR测量精确度。
OFDR的测量精度比OTDR高，可以达到皮秒量级；测量范围比OLCR大，可达几千米，具有较高的实用性。但此方法需要一段定长光纤作为参考光路，容易受温度的影响而降低测量准确度。
发明概述
技术问题
问题的解决方案
技术解决方案
鉴于上述，本发明提供了一种保偏光纤主轴差分延时的测量装置。该测量装置可以达到皮秒量级的测量精度和千米级的动态范围。
本发明的技术方案为：
一种保偏光纤主轴差分延时的测量装置，包括保偏光纤萨格奈克干涉仪、信号发生器，微波检波器，微处理器，其中：
所述保偏光纤萨格奈克干涉仪包括依次连接的激光器、光电调制器、保偏光纤耦合器、还包括设置在保偏光纤耦合器两个输出端的光纤接口J1、光纤接口J2设置在光纤接口J1、光纤接口J2之间的待测保偏光纤，以及设置在保偏光纤耦合器另一输出端的光电探测器；激光器发出的低相干线偏振光经光电调制器搭载射频信号后，由保偏光纤保偏光纤耦合器分为两路输出，其中沿保偏光纤耦合器快轴输出的一路光经光纤接口J1进入待测保偏光纤仍沿着快轴传播，沿着保偏光纤耦合器快轴输出的另一路光经光纤接口J2耦合到待测保偏光纤的慢轴上，两束在不同轴上的光相向传播，待测保偏光纤的快轴上的光传播到待测保偏光纤的另一端时又经光纤接口J2耦合到保偏光纤耦合器的慢轴上，待测保偏光纤慢轴上的光传播到待测保偏光纤另一端经光纤接口J1不改变传播轴进入保偏光纤耦合器的慢轴，两束光叠加输出，经光电探测器将光信号转化为电信号；
所述信号发生器，产生扫频射频信号，该扫频射频信号经光电调制器、被调制到光信号上；
所述微波检波器设置在光电探测器的输出端，用于检测光电探测器输出的射频信号的功率；
所述微控制器与所述微波检波器连接，用于根据所述微波检波器的输出信号计算保偏光纤产生的光延时。
所述微控制器根据以下公式计算获得保偏光纤主轴差分延时量：
Figure PCTCN2020073568-appb-000001
其中，
f RF0
与
f RF1
为相邻的检波检测器输出的电压为0的频点值。
该装置用了光在保偏光纤的快轴和慢轴具有不同的传播常数会产生延时差来测量该待测光纤的长度，采用萨格奈克干涉仪的结构，无需参考光路减小了温度对测量准确度的影响。同时结合了基于微波光子技术的延时测量方法，可以达到皮秒量级的测量精度和千米级的动态范围。
发明的有益效果
对附图的简要说明
附图说明
为了更清楚地说明本发明实施例或现有技术中的技术方案，下面将对实施例或现有技术描述中所需要使用的附图做简单地介绍，显而易见地，下面描述中的附图仅仅是本发明的一些实施例，对于本领域普通技术人员来讲，在不付出创造性劳动前提下，还可以根据这些附图获得其他附图。
图1是本发明保偏光纤主轴差分延时的测量装置的系统示意图；
图2是保偏光纤的结构示意图；
图3是光纤接口的结构示意图，其中，图3(a)为光纤接口J2要保证的连接方式；图3(b)为光纤接口J1要保证的连接方式。
发明实施例
本发明的实施方式
为使本发明的目的、技术方案及优点更加清楚明白，以下结合附图及实施例对本发明进行进一步的详细说明。应当理解，此处所描述的具体实施方式仅仅用以解释本发明，并不限定本发明的保护范围。
如图1所示，本发明提供的保偏光纤主轴差分延时的测量装置包括：激光器(DFB)1，信号发生器(Signal Source)2，光电调制器(MZM)3，保偏光纤耦合器(OC)4，光纤接口J1，光纤接口J2，待测保偏光纤5，光电探测器(PD)6，微波检波器(Radio Detector)7和微控制器(MCU)8。
其中，激光器1，光电调制器3，保偏光纤耦合器4，光纤接口J1，光纤接口J2，光电探测器6以及待测保偏光纤5组成保偏光纤萨格奈克干涉仪。如图2所示，待测保偏光纤5具有两个传输轴，一个是快轴，另外一个是与快抽垂直的慢轴。如图3(a)和图3(b)所示，光纤接口J1与光纤接口J2用来将保偏光纤耦合器4和待测保偏光纤5连接起来。光纤接口J1保证要连接的两段光纤的快轴和快轴对准，慢轴和慢轴对准。光纤接口J2保证要连接的两段光纤的快轴和慢轴对准，慢轴和快轴对准。
具体地，激光器1采用的是相干长度小于30um的宽谱光源，其相干长度远远小于保偏光纤快轴和慢轴由于传播常数不同而引起的光程差。并且，激光器1发出线偏振光。
具体地，保偏光纤耦合器4为2×2 3dB保偏光纤耦合器，并且，保偏光纤耦合器4连接光纤接口J1、光纤接口J2的两段保偏光纤等长。
工作时，激光器1发出的低相干线偏振光经光电调制器3搭载射频信号后，由保偏光纤保偏光纤耦合器4分为两路输出。其中，在保偏光纤耦合器b端口沿着快轴输出的一路光经光纤接口J1进入待测保偏光纤5仍沿着快轴传播；保偏光纤耦合器c端口沿着快轴输出的另一路光经光纤接口J2耦合到待测保偏光纤5的慢轴上，两束在不同轴上的光相向传播。待测保偏光纤5的快轴上的光传播到待测保偏光纤5的另一端时又经光纤接口J2耦合到保偏光纤耦合器4的慢轴上，待测保偏光纤5慢轴上的光传播到待测保偏光纤5另一端经光纤接口J1不改变传播轴进入保偏 光纤耦合器4的慢轴，两束光叠加输出，经光电探测器6将光信号转化为电信号。
信号发生器2产生的一组扫频射频信号调制到光上后进入保偏光纤萨格奈克干涉仪，由于待测保偏光纤的快轴和慢轴的传播常数不同，因此到达输出端时两轴上的光存在延时差，叠加输出的光信号经光电探测器转化为电信号后其幅度将携带延时信息，经微波检波器7和微控制器8计算待测保偏光纤6产生的光延时。
上述保偏光纤主轴差分延时的测量装置的工作原理如下：
信号发生器2产生的射频信号可以表示为：
Figure PCTCN2020073568-appb-000002
其中，
V RF
表示射频信号幅值，
ω RF
表示射频信号频率。
加在光电调制器上的偏置电压为：
Figure PCTCN2020073568-appb-000003
所产生的光相位变化为：
Figure PCTCN2020073568-appb-000004
其中，
V DC
为稳压直流电源提供的直流电压，
V π
为光电调制器的半波电压。式子(3)的第一部分是直流偏置产生的相位变化，第二部分是由调制信号产生的相位变化。当初始相位在
Figure PCTCN2020073568-appb-000005
，且输入信号为小信号时，激光功率的变化趋于线性状态。因此一般情况下光电调制器偏置点都要放置在半波电压，即
Figure PCTCN2020073568-appb-000006
，这样就可使产品中所使用的一阶电信号增益为最大值，同时可以很好的抑制高次谐波信号。
经过微波调制的激光，在光电调制器输出端的表达形式为：
Figure PCTCN2020073568-appb-000007
其中：
α loss
光电调制器的损耗，
P 0
是激光器输入的光强，
P out(t)
是光电调制器输出的光强，经过一个2×2的3dB保偏光纤耦合器被分成两束光，一路光沿着保偏光纤的快轴传播，另一路经偏振控制器耦合到保偏光纤的慢轴。保偏光纤快轴和慢轴中的光信号分别可以表示为：
Figure PCTCN2020073568-appb-000008
Figure PCTCN2020073568-appb-000009
Figure PCTCN2020073568-appb-000010
Figure PCTCN2020073568-appb-000011
其中，
Figure PCTCN2020073568-appb-000012
是射频信号在快轴中产生的相位的变化量，
Figure PCTCN2020073568-appb-000013
是射频信号在慢轴中产生的相位的变化量，
τ f
是射频信号在快轴中的延时，
τ s
是射频信号在慢轴中的延时。由于激光器为低相干光源，满足条件：
Figure PCTCN2020073568-appb-000014
其中：
f RF
是射频信号的频率，L是待测保偏光纤的拍长，
τ
是光在待测保偏光纤的快轴和慢轴传播时产生的延时差。因此，沿快轴和慢轴传播的两束光在保偏光纤耦合器叠加输出，输出的光信号到光电探测器中，忽略直流分量，可得一阶信号输出的电流为：
Figure PCTCN2020073568-appb-000015
＝
Figure PCTCN2020073568-appb-000016
其中，
η
为光电转化效率，
α loss
是光电调制器的损耗。光电探测器输出的信号放大后输入到检波检测器中得到输出信号：
Figure PCTCN2020073568-appb-000017
可以看到，输出电压Vout的大小和f RF满足余弦关系。余弦函数的周期和(τ s-τ f)
的值有关。只要测得相邻的两个Vout为0的频点f RF0和f RF1，即可得到延时量：
Figure PCTCN2020073568-appb-000018
本保偏光纤主轴差分延时测量的方法装置利用了光在保偏光纤的快轴和慢轴具有不同的传播常数会产生延时差来测量该待测光纤的长度，采用萨格奈克干涉仪的结构，无需参考光路减小了温度对测量准确度的影响。同时结合了基于微波光子技术的延时测量方法，可以达到皮秒量级的测量精度和千米级的动态范 围。
以上所述的具体实施方式对本发明的技术方案和有益效果进行了详细说明，应理解的是以上所述仅为本发明的最优选实施例，并不用于限制本发明，凡在本发明的原则范围内所做的任何修改、补充和等同替换等，均应包含在本发明的保护范围之内。

Claims (6)

  1. 一种保偏光纤主轴差分延时的测量装置，其特征在于，包括保偏光纤萨格奈克干涉仪、信号发生器，微波检波器，微处理器，其中：所述保偏光纤萨格奈克干涉仪包括依次连接的激光器、光电调制器、保偏光纤耦合器、还包括设置在保偏光纤耦合器两个输出端的光纤接口J1、光纤接口J2设置在光纤接口J1、光纤接口J2之间的待测保偏光纤，以及设置在保偏光纤耦合器另一输出端的光电探测器；激光器发出的低相干线偏振光经光电调制器搭载射频信号后，由保偏光纤保偏光纤耦合器分为两路输出，其中沿保偏光纤耦合器快轴输出的一路光经光纤接口J1进入待测保偏光纤仍沿着快轴传播，沿着保偏光纤耦合器快轴输出的另一路光经光纤接口J2耦合到待测保偏光纤的慢轴上，两束在不同轴上的光相向传播，待测保偏光纤的快轴上的光传播到待测保偏光纤的另一端时又经光纤接口J2耦合到保偏光纤耦合器的慢轴上，待测保偏光纤慢轴上的光传播到待测保偏光纤另一端经光纤接口J1不改变传播轴进入保偏光纤耦合器的慢轴，两束光叠加输出，经光电探测器将光信号转化为电信号；所述信号发生器，产生扫频射频信号，该扫频射频信号经光电调制器、被调制到光信号上；所述微波检波器设置在光电探测器的输出端，用于检测光电探测器输出的射频信号的功率；所述微控制器与所述微波检波器连接，用于根据所述微波检波器的输出信号计算保偏光纤产生的光延时。
  2. 如权利要求1所述的保偏光纤主轴差分延时的测量装置，其特征在于，所述激光器采用的是相干长度小于30μm的宽谱光源，其相干长度远远小于保偏光纤快轴和慢轴由于传播常数不同而引起的光程差。
  3. 如权利要求2所述的保偏光纤主轴差分延时的测量装置，其特征在于，所述激光器发出线偏振光。
  4. 如权利要求1所述的保偏光纤主轴差分延时的测量装置，其特征在于，所述保偏光纤耦合器为2×2 3dB保偏光纤耦合器。
  5. 如权利要求4所述的保偏光纤主轴差分延时的测量装置，其特征在于，所述保偏光纤耦合器连接光纤接口J1、光纤接口J2的两段保偏光纤等长。
  6. 如权利要求1所述的保偏光纤主轴差分延时的测量装置，其特征在于，所述微控制器根据以下公式计算获得保偏光纤主轴差分延时量：
    Figure PCTCN2020073568-appb-100001
    其中，
    f RF0
    与
    f RF1
    为相邻的两个检波检测器输出的电压为0的频点值。
PCT/CN2020/073568 2019-03-28 2020-01-21 一种保偏光纤主轴差分延时的测量装置 WO2020192269A1 (zh)

Priority Applications (2)

Application Number Priority Date Filing Date Title
JP2021514965A JP7086335B2 (ja) 2019-03-28 2020-01-21 偏波保持光ファイバ主軸差分時間遅延の測定装置
US17/194,290 US11159233B2 (en) 2019-03-28 2021-03-07 Measuring device for polarization-maintaining optical fiber spindle differential delay

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
CN201910242806.4 2019-03-28
CN201910242806.4A CN109831249B (zh) 2019-03-28 2019-03-28 一种保偏光纤主轴差分延时的测量装置

Related Child Applications (1)

Application Number Title Priority Date Filing Date
US17/194,290 Continuation US11159233B2 (en) 2019-03-28 2021-03-07 Measuring device for polarization-maintaining optical fiber spindle differential delay

Publications (1)

Publication Number Publication Date
WO2020192269A1 true WO2020192269A1 (zh) 2020-10-01

Family

ID=66873021

Family Applications (1)

Application Number Title Priority Date Filing Date
PCT/CN2020/073568 WO2020192269A1 (zh) 2019-03-28 2020-01-21 一种保偏光纤主轴差分延时的测量装置

Country Status (4)

Country Link
US (1) US11159233B2 (zh)
JP (1) JP7086335B2 (zh)
CN (1) CN109831249B (zh)
WO (1) WO2020192269A1 (zh)

Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN114745045A (zh) * 2022-03-10 2022-07-12 吉林大学 一种基于c-otdr的少模光纤差分模式群时延测量方法
CN115955280A (zh) * 2023-03-13 2023-04-11 万事通科技(杭州)有限公司 一种光纤信道窃听检测装置

Families Citing this family (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN109831249B (zh) * 2019-03-28 2020-02-18 浙江大学 一种保偏光纤主轴差分延时的测量装置

Citations (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN1584649A (zh) * 2004-06-03 2005-02-23 清华大学 基于光纤环镜的光标签擦除滤波器
CN102494681A (zh) * 2011-12-06 2012-06-13 北京航空航天大学 一种基于双折射调制的差分双干涉式光纤陀螺仪
US9115993B1 (en) * 1990-08-30 2015-08-25 The Charles Stark Draper Laboratory, Inc. Fused PM fiber single-polarization resonator
CN206496890U (zh) * 2017-02-24 2017-09-15 北京世维通光智能科技有限公司 保偏光纤延时环测试系统
CN109831249A (zh) * 2019-03-28 2019-05-31 浙江大学 一种保偏光纤主轴差分延时的测量装置

Family Cites Families (10)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US7315699B2 (en) * 2004-04-26 2008-01-01 Lucent Technologies Inc. Optical device for extracting a sideband signal from a composite signal including orthogonally modulated signals
CN101592551B (zh) * 2009-06-05 2011-01-12 北京航空航天大学 一种基于Sagnac干涉仪的保偏光纤拍长测试方法及测试装置
JPWO2011115293A1 (ja) * 2010-03-19 2013-07-04 古河電気工業株式会社 偏波無依存波長変換器および偏波無依存波長変換方法
US8599385B2 (en) * 2010-05-14 2013-12-03 General Photonics Corporation Measuring distributed polarization crosstalk in polarization maintaining fiber and optical birefringent material
JP5936057B2 (ja) * 2012-08-27 2016-06-15 国立大学法人 東京大学 光ファイバ特性測定装置及び光ファイバ特性測定方法
CN203259329U (zh) * 2013-05-10 2013-10-30 武汉钜风科技有限公司 保偏光纤中偏振模耦合分布的测量装置
CN103363905A (zh) * 2013-07-02 2013-10-23 北京航空航天大学 一种基于光谱分析的保偏光纤长度测量系统及其方法
WO2016042507A1 (en) * 2014-09-17 2016-03-24 Ecole Polytechnique Federale De Lausanne (Epfl) Method and apparatus for measuring the local birefingence along an optical waveguide
US9476699B2 (en) * 2015-03-05 2016-10-25 General Photonics Corporation Measurements of strain, stress and temperature by using 1-dimensional and 2-dimensional distributed fiber-optic sensors based on sensing by polarization maintaining fiber of distributed polarization crosstalk distribution
CN105865752B (zh) * 2016-03-10 2020-02-14 苏州光环科技有限公司 采用分布式偏振串扰分析仪全面评判保偏光纤特性的方法和装置

Patent Citations (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US9115993B1 (en) * 1990-08-30 2015-08-25 The Charles Stark Draper Laboratory, Inc. Fused PM fiber single-polarization resonator
CN1584649A (zh) * 2004-06-03 2005-02-23 清华大学 基于光纤环镜的光标签擦除滤波器
CN102494681A (zh) * 2011-12-06 2012-06-13 北京航空航天大学 一种基于双折射调制的差分双干涉式光纤陀螺仪
CN206496890U (zh) * 2017-02-24 2017-09-15 北京世维通光智能科技有限公司 保偏光纤延时环测试系统
CN109831249A (zh) * 2019-03-28 2019-05-31 浙江大学 一种保偏光纤主轴差分延时的测量装置

Non-Patent Citations (1)

* Cited by examiner, † Cited by third party
Title
ANHUA ET AL.: "Research and Application of Optical Fiber Sagnac Loop", ELECTRO-OPTIC TECHNOLOGY APPLICATION, vol. 28, no. 6, 31 December 2013 (2013-12-31), XP055738463 *

Cited By (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN114745045A (zh) * 2022-03-10 2022-07-12 吉林大学 一种基于c-otdr的少模光纤差分模式群时延测量方法
CN114745045B (zh) * 2022-03-10 2023-11-03 吉林大学 一种基于c-otdr的少模光纤差分模式群时延测量方法
CN115955280A (zh) * 2023-03-13 2023-04-11 万事通科技(杭州)有限公司 一种光纤信道窃听检测装置

Also Published As

Publication number Publication date
US20210226700A1 (en) 2021-07-22
CN109831249B (zh) 2020-02-18
CN109831249A (zh) 2019-05-31
JP2022500940A (ja) 2022-01-04
JP7086335B2 (ja) 2022-06-20
US11159233B2 (en) 2021-10-26

Similar Documents

Publication Publication Date Title
WO2020192269A1 (zh) 一种保偏光纤主轴差分延时的测量装置
CN109547098B (zh) 一种微波光子延时测量校准装置
CN103900797B (zh) 带有光程扫描位置和速度校正的光学相干域偏振测量装置
CN102494617B (zh) 一种单模光纤长度测量系统
US20030103211A1 (en) Sensor and method for detecting fiber optic faults
CN103900798B (zh) 一种带有光程扫描在线校正的光学相干域偏振测量装置
CN104132798A (zh) 一种y波导集成光学相位调制器调制系数测量装置和方法
CN103900680A (zh) 一种利用光源抑制偏振串音测量噪声的装置及检测方法
CN104618013A (zh) 一种基于全光纤宽谱混沌光源的相关光时域反射仪
CN107314888B (zh) 多功能铌酸锂集成器件的偏振性能测量方法
CN106441083B (zh) 激光回馈干涉仪
Hong et al. Location of a wideband perturbation using a fiber Fox–Smith interferometer
CN107976300B (zh) 一种保偏光纤拍长的测量方法
CN110726468A (zh) 一种基于直波导相位调制器的分布式光纤声波传感系统
CN113804301A (zh) 一种基于光频域移频干涉的分布式偏振串音快速测量装置
Kobayashi et al. Optical fiber component characterization by high-intensity and high-spatial-resolution interferometric optical-time-domain reflectometer
CN209979850U (zh) 基于oeo快速切换的大量程、高精度绝对距离测量仪器
CN108709720B (zh) 一种高双折射保偏光纤的模式双折射的测量装置和方法
CN101592526A (zh) 一种光平均波长的测量方法及装置
CN111162835A (zh) 光时域反射仪
CN108007307B (zh) 一种光纤的测量方法以及测量装置
CN113834508B (zh) 基于互注入半导体激光器和非平衡马赫-曾德尔干涉仪的分布式光纤传感系统及其定位方法
CN110186500A (zh) 一种采用绝对法的非平衡光纤干涉仪臂长差测量装置及测量方法
CN205719932U (zh) 一种用于测试透光介质双折射率差值的装置
CN211926897U (zh) 一种光源噪声改善前馈结构及光纤振动测量装置

Legal Events

Date Code Title Description
121 Ep: the epo has been informed by wipo that ep was designated in this application

Ref document number: 20779370

Country of ref document: EP

Kind code of ref document: A1

DPE1 Request for preliminary examination filed after expiration of 19th month from priority date (pct application filed from 20040101)
ENP Entry into the national phase

Ref document number: 2021514965

Country of ref document: JP

Kind code of ref document: A

NENP Non-entry into the national phase

Ref country code: DE

122 Ep: pct application non-entry in european phase

Ref document number: 20779370

Country of ref document: EP

Kind code of ref document: A1