Optical time-domain reflectometer

A technology of time domain reflectometry and optical fiber, applied in electromagnetic wave transmission systems, electrical components, transmission systems, etc., can solve the problems of small dynamic range, large dark current and thermal noise, etc. Effect

Active Publication Date: 2015-03-18
张强
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

Due to the large dark current and thermal noise of classic photodetectors, the value of OTDR is generally -110dbm, resulting in a small dynamic range that OTDR can measure

Method used

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  • Optical time-domain reflectometer

Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1

[0056] figure 1 It is a structural schematic diagram of Embodiment 1 of an optical fiber time domain reflectometer according to the present invention, and the device includes:

[0057] Trigger 101 , laser 102 , attenuator 103 , circulator 104 , up-conversion single-photon detector 105 and time-to-digital converter 106 .

[0058] The trigger 101 is used to output an electric pulse signal with a preset frequency.

[0059] Optionally, the trigger 101 includes: a microwave signal generator 107 and an encoder 108,

[0060] The microwave signal generator 107 is used to output an initial pulse signal;

[0061]The encoder 108 is used to encode the initial pulse signal, and output an electric pulse signal with a preset frequency.

[0062] It should be noted here that the trigger 101 can also be composed of other devices capable of outputting electrical pulse signals with a preset frequency, and details will not be repeated here.

[0063] Optionally, the model of the microwave signa...

Embodiment 2

[0104] figure 2 It is a schematic structural diagram of Embodiment 2 of an optical fiber time domain reflectometer according to the present invention. Compared with Embodiment 1, the device further includes a polarization controller, and the device includes:

[0105] Trigger 101 , laser 102 , attenuator 103 , circulator 104 , up-converting single photon detector 105 , time-to-digital converter 106 and polarization controller 201 .

[0106] Wherein, the optical signal is transmitted between the laser 102 , the attenuator 103 , the circulator 104 and the up-conversion single-photon detector 106 through a single-mode optical fiber.

[0107] The pulse signal light passes between the laser 102, the attenuator 103, the circulator 104 and the detection fiber, and the backscattered light passes through the single-mode fiber optic transmission.

[0108]The electrical pulse signal output by the trigger 101 triggers the laser 102 to generate the pulse signal light of the same frequenc...

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PUM

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Abstract

The invention discloses an optical time-domain reflectometer comprising a trigger, a laser, an attenuator, a circulator, an up-conversion single-photon detector and a time-to-digital converter. The optical time-domain reflectometer (OTDR) of the invention employs the up-conversion single-photon detector. The up-conversion single-photon detector employs a pump light wavelength of 1900 nm to 2000 nm to carry out narrowband filtering on sum frequency light, a noise equivalent power (NEP) lower than the NEP of a classic detector is obtained under the same quantum efficiency, and the NEP value can reach -140dbm. The lower the NEP value is, the larger the detected dynamic range is. Therefore, the up-conversion single-photon detector effectively increases the detectable dynamic range of the OTDR, the detection resolution is improved, the measuring time is reduced, and dead zones after a Fresnel reflection peak are effectively prevented.

Description

technical field [0001] The invention relates to the field of optical fiber communication, in particular to an optical fiber time domain reflectometer. Background technique [0002] At present, with the continuous development of optical communication, an important branch of optical communication - Optical Fiber Communications (Optical Fiber Communications) is gradually replacing cables and microwave communications due to its advantages of wide transmission frequency bandwidth, high anti-interference and low signal attenuation. It has become the main transmission method in the world communication. Optical fiber communication is a communication method that uses light waves as a carrier and optical fiber as a transmission medium to transmit information from one place to another. It is called "wired" optical communication. Therefore, the performance of optical fiber directly affects the speed and distance of optical signal transmission. [0003] Lightning, earthquakes, and cons...

Claims

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Application Information

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Patent Type & Authority Applications(China)
IPC IPC(8): H04B10/071
Inventor 张强申屠国樑
Owner 张强
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