CN218570232U

CN218570232U - Optical fiber bending position measuring device

Info

Publication number: CN218570232U
Application number: CN202222828749.8U
Authority: CN
Inventors: 蒋灵芝; 胡肖潇; 姚飞
Original assignee: GUILIN G-LINK TECHNOLOGY CO LTD
Current assignee: GUILIN G-LINK TECHNOLOGY CO LTD
Priority date: 2022-10-26
Filing date: 2022-10-26
Publication date: 2023-03-03
Anticipated expiration: 2032-10-26

Abstract

The utility model discloses a measure device of optic fibre bending position changes the polarization state of injecting into the light signal of being surveyed in the optic fibre, acquires the crooked position location numerical value that changes of optical cable that corresponds with the polarization state after changing, when acquireing the crooked quantity that changes the position location numerical value of optical cable reaches appointed numerical value, with each the crooked position location numerical value that changes of optical cable is ordered according to the numerical value size as the optic fibre length value, and is minimum with the numerical value optic fibre length value does by being surveyed the fine bending position measurement result of light. The influence of the optical fiber birefringence on the positioning and measuring result of the bending position of the optical cable can be effectively eliminated, the measuring precision is improved, and the error is reduced.

Description

Optical fiber bending position measuring device

Technical Field

The utility model relates to an optical fiber sensing measures technical field, in particular to crooked position measuring device of optic fibre.

Background

When using OTDR to quickly and accurately find the location of a fault point on an optical cable, it is often necessary to select one or more reference points in the optical cable link and to know the length of the optical fiber between these reference points and the OTDR measurement point. In order to losslessly measure the length of the optical fiber between the reference point and the OTDR measurement point, the prior art performs time-varying bending on the optical cable at the reference point position, the bending diameter varies by 0.5m to 1m, and then uses the P-OTDR to measure the length of the optical fiber between the bending variation position of the optical cable and the P-OTDR measurement end point.

In cable eavesdropping prevention systems, P-OTDR is also used to detect the occurrence of cable eavesdropping activity. When an illegal person eavesdrops on the communication optical cable system, the optical fiber in the optical cable or the optical fiber in the cable protective case needs to be taken out for processing, and the curvature of the optical fiber inevitably changes in the process. The P-OTDR used in the optical cable anti-eavesdropping system can detect the change of the curvature of the optical fiber and measure the length of the optical fiber between the position of the change of the curvature of the optical fiber and a P-OTDR measurement end point, thereby generating an alarm and positioning.

The length of the optical fiber between the bending change position of the optical cable to the P-OTDR measurement end point is measured by using the P-OTDR, and the principle is to measure the position of the change of the polarization state of the light scattering signal in the measured optical fiber.

However, the utility model discloses a people is realizing the utility model discloses an in-process discovers, in actual optical cable, because there is the birefringence phenomenon in the optic fibre, along optic fibre axial length, different optic fibre positions, the polarization state of light scattering signal is slowly-changed with time. When the length of the optical fiber between the bending change position of the optical cable and the OTDR measurement point is measured by using the P-OTDR, because the optical scattering signal at the bending change position of the optical cable is possibly in a certain polarization state, the change amplitude of the scattering optical signal obtained by the P-OTDR due to the bending of the optical cable is very small in the polarization state, and the change amplitude of the scattering optical signal is larger after a certain distance is needed, namely half of the optical fiber birefringence beat length.

Therefore, the length value of the optical fiber obtained sometimes is larger than the actual value through the existing measuring method, the error can reach 5 m-50 m, the error value is related to the beat length of the birefringence of the optical fiber, the beat length value of the birefringence of the optical fiber is large, and the positioning error obtained through P-OTDR is larger. Therefore, how to improve the positioning accuracy in the optical fiber measurement in response to the birefringence problem becomes a technical problem that needs to be solved by those skilled in the art.

SUMMERY OF THE UTILITY MODEL

The utility model aims at providing an improve P-OTDR positioning accuracy's measuring device and method to eliminate the influence that the optic fibre birefringence arouses, improve measuring precision.

In order to achieve the above object, the utility model provides a following scheme:

in a first aspect, a method for measuring a bending position of an optical fiber is provided, which is applied in a P-OTDR positioning measurement system, and the method includes:

changing the polarization state of the optical signal injected into the tested optical fiber;

obtaining an optical cable bending change position positioning value corresponding to the changed polarization state;

when the number of the obtained optical cable bending change position positioning values reaches a specified value, sequencing the optical cable bending change position positioning values serving as optical fiber length values according to the value;

and taking the optical fiber length value with the minimum value as the bending position measurement result of the measured optical fiber.

In some embodiments, the polarization state of the optical signal injected into the measured optical fiber is changed, specifically:

and setting the polarization angle of the optical signal currently injected into the tested optical fiber according to a preset change value range.

In some embodiments, the specified numerical value is an integer of 10 or less and 2 or more;

the change value ranges from 10 degrees to 90 degrees.

In a second aspect, there is provided an optical fiber bending position measuring apparatus, the apparatus comprising:

the optical transmitter is connected with the control and calculation unit and the polarization controller and is used for injecting optical signals into the optical fiber to be measured;

the polarization controller is connected with the optical transmitter and the optical directional coupler and is used for changing the polarization state of the optical signal injected into the tested optical fiber;

the light direction coupler is respectively connected with the polarization controller, the tested optical fiber and the analyzer;

the polarization analyzer is connected with the optical directional coupler and is used for carrying out polarization state detection operation on the signals fed back by the optical directional coupler;

the optical receiver is respectively connected with the analyzer and the control and calculation unit;

and the control and calculation unit is used for acquiring optical cable bending change position positioning values corresponding to the changed polarization state, sequencing the optical cable bending change position positioning values serving as optical fiber length values according to the numerical values when the number of the acquired optical cable bending change position positioning values reaches a specified numerical value, and taking the optical fiber length value with the minimum numerical value as a bending position measurement result of the measured optical fiber.

In some embodiments, wherein the polarization controller is specifically configured to:

the change value ranges from 10 degrees to 90 degrees.

By applying the technical scheme, the influence of the optical fiber birefringence on the positioning and measuring result of the bending position of the optical cable can be effectively eliminated, the measuring precision is improved, and the error is reduced.

Drawings

In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required to be used in the embodiments will be briefly described below, and it is obvious that the drawings in the following description are only some embodiments of the present invention, and for those skilled in the art, other drawings can be obtained according to these drawings without inventive labor.

Fig. 1 is a schematic flow chart of a method for measuring a bending position of an optical fiber according to the present invention.

Fig. 2 is a schematic structural diagram of an apparatus for measuring a bending position of an optical fiber according to the present invention.

Fig. 3 is a schematic diagram of a processing step of measuring bending position data of an optical fiber according to an embodiment of the present invention.

Detailed Description

The technical solutions in the embodiments of the present application will be clearly and completely described below with reference to the drawings in the embodiments of the present application, and it is obvious that the described embodiments are only a part of the embodiments of the present application, and not all of the embodiments. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present application.

It is noted that other embodiments of the present application will become apparent to those skilled in the art from consideration of the specification and practice of the invention disclosed herein. This application is intended to cover any variations, uses, or adaptations of the invention following, in general, the principles of the application and including such departures from the present disclosure as come within known or customary practice within the art to which the invention pertains. It is intended that the specification and examples be considered as exemplary only, with a true scope and spirit of the application being indicated by the following claims.

It is to be understood that the present application is not limited to the precise construction herein after described and illustrated in the accompanying drawings, and that various modifications and changes may be made without departing from the scope thereof. The scope of the application is limited only by the appended claims.

A method of measuring a bend location of an optical fiber according to an exemplary embodiment of the present application is described below with reference to fig. 1. It should be noted that the following application scenarios are merely illustrated for the convenience of understanding the spirit and principles of the present application, and the embodiments of the present application are not limited in this respect. Rather, embodiments of the present application may be applied to any scenario where applicable.

The embodiment of the present application provides a method for measuring a bending position of an optical fiber, as shown in fig. 1, the method includes the following steps:

step 301, changing the polarization state of the optical signal injected into the tested optical fiber, wherein the change value range of the polarization angle of the optical signal every time is between 10 and 90 degrees;

step 302, obtaining optical cable bending change position positioning values corresponding to the changed polarization state, and obtaining N optical fiber length values, wherein N is more than or equal to 2 and less than or equal to 10;

step 303, when the number of the obtained optical cable bending change position location values reaches a specified value, taking each optical cable bending change position location value as an optical fiber length value to be sequenced according to the value;

and step 304, taking the optical fiber length value with the minimum value as the bending position measurement result of the measured optical fiber.

Correspondingly, the utility model also provides an optic fibre bending position measuring device, as shown in figure 2, the device includes:

an optical transmitter 601 connected to the control and calculation unit and the polarization controller, for injecting an optical signal into the optical fiber to be tested;

a polarization controller 602 connected to the optical transmitter and the optical directional coupler, for changing the polarization state of the optical signal injected into the tested optical fiber;

a light directional coupler 603, which is respectively connected to the polarization controller, the measured optical fiber and the analyzer;

an analyzer 604 connected to the optical directional coupler for performing a polarization state detection operation on the signal fed back by the optical directional coupler;

an optical receiver 605 connected to the analyzer and the control and calculation unit, respectively;

the control and calculation unit 606 is configured to obtain optical cable bending change position location values corresponding to the changed polarization state, sort the optical cable bending change position location values serving as optical fiber length values according to the size of the optical fiber when the number of the obtained optical cable bending change position location values reaches a specified value, and take the optical fiber length value with the smallest value as a bending position measurement result of the measured optical fiber.

In a particular embodiment of the present application, the polarization controller is specifically configured to:

In specific embodiments of the present application, the specified numerical values are integers of 10 or less and 2 or more; the change value ranges from 10 degrees to 90 degrees.

By applying the technical scheme, the polarization state of the optical signal injected into the tested optical fiber is changed, optical cable bending change position location values corresponding to the changed polarization state are obtained, when the number of the obtained optical cable bending change position location values reaches a specified value, the optical cable bending change position location values are used as optical fiber length values to be sequenced according to the value size, and the optical fiber length value with the minimum value is used as a bending position measurement result of the tested optical fiber. The influence of the optical fiber birefringence on the positioning and measuring result of the bending position of the optical cable can be effectively eliminated, the measuring precision is improved, and the error is reduced.

The communication bus may be a PCI (peripheral component interconnect) bus, an EISA (extended industry standard architecture) bus, or the like. The communication bus may be divided into an address bus, a data bus, a control bus, etc. For ease of illustration, only one thick line is shown, but this does not mean that there is only one bus or one type of bus.

The communication interface is used for communication between the terminal and other equipment.

The memory may include a RAM (random access memory) or may include a nonvolatile memory such as at least one disk memory. Optionally, the memory may also be at least one memory device located remotely from the processor.

The processor may be a general-purpose processor including a CPU (central processing unit), an NP (network processor), and the like; but also a DSP (Digital signal processing), an ASIC (Application specific integrated circuit), an FPGA (Field Programmable gate array) or other Programmable logic device, discrete gate or transistor logic device, discrete hardware component.

In a further embodiment of the present invention, there is also provided a computer-readable storage medium having stored thereon a computer program which, when executed by a processor, implements the optical fiber bending position measuring method as described above.

Claims

1. An optical fiber bending position measuring apparatus, comprising:

the optical transmitter is connected with the control and calculation unit and the polarization controller and is used for injecting optical signals into the optical fiber to be detected;

the optical directional coupler is respectively connected with the polarization controller, the measured optical fiber and the analyzer;

2. The apparatus of claim 1, wherein the polarization controller is specifically configured to:

3. The apparatus of claim 2,

the specified numerical value is an integer of 10 or less and 2 or more;

the change value ranges from 10 degrees to 90 degrees.