Optical pulse tester and measurement method

Abstract

To easily and accurately measure crosstalk between cores in a multicore optical fiber.SOLUTION: An optical pulse tester 10 according to the present disclosure measures crosstalk between cores of a multicore optical fiber 1. The optical pulse tester 10 includes a laser element 12 configured to generate an optical pulse, an output port 20 configured to output the optical pulse to one of a plurality of cores in the multicore optical fiber 1, an input port 30 configured to receive backscattered light generated in a core other than the one core among the plurality of cores, and a photodetector 13 configured to detect the backscattered light received by the input port 30.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present disclosure relates to an optical time domain tester and a measurement method. [Background technology]

[0002] Optical fibers include single-core optical fibers that have one core and multi-core optical fibers that have multiple cores.

[0003] Multi-core optical fibers have multiple cores densely arranged in the cladding, which causes crosstalk between the cores.

[0004] Conventionally, various techniques have been studied for measuring crosstalk between cores in a multi-core optical fiber. For example, Patent Document 1 discloses a technique for measuring crosstalk using multiple OTDR (Optical Time Domain Reflectometer) devices. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] Japanese Patent Application Publication No. 2012-202827 Summary of the Invention [Problem to be solved by the invention]

[0006] The measurement method described in Patent Document 1 requires the use of multiple OTDR devices, and it is not possible to easily measure crosstalk between cores in a multi-core optical fiber.

[0007] Another possible method for measuring crosstalk between cores in a multi-core optical fiber is to input an optical pulse into one of the multiple cores via an optical directional coupler and receive and measure backscattered light generated in the other cores via the same optical directional coupler. However, with this measurement method, the blocking ability of the optical directional coupler is not perfect, so the backscattered light from the core to which the optical pulse is input leaks out through the optical directional coupler and is added to the backscattered light generated in the other cores. Therefore, it is difficult to measure only the backscattered light generated in the other cores, and it is difficult to measure crosstalk accurately.

[0008] Therefore, an object of the present disclosure is to provide an optical time domain reflectometer and a measurement method that can easily and accurately measure crosstalk between cores in a multi-core optical fiber. [Means for solving the problem]

[0009] An optical time domain reflectometer according to some embodiments is an optical time domain reflectometer for measuring crosstalk between cores of a multi-core optical fiber, and includes: a laser element for generating an optical pulse; an output port for outputting the optical pulse to one of a plurality of cores of the multi-core optical fiber; an input port for receiving backscattered light generated in a core other than the one of the plurality of cores; and a photodetector for detecting the backscattered light received by the input port. With such an optical time domain reflectometer, it is possible to easily and accurately measure crosstalk between cores in a multi-core optical fiber.

[0010] In one embodiment of the optical time domain tester, a plurality of the input ports may be provided, thereby allowing a plurality of backscattered lights to be received simultaneously.

[0011] In one embodiment of the optical time domain tester, a plurality of the optical receivers may be connected to the plurality of input ports, respectively, thereby enabling crosstalk of a plurality of cores to be measured simultaneously.

[0012] In one embodiment, the optical time domain tester further includes an optical switch connected to the plurality of input ports, and the optical switch outputs any one of the plurality of backscattered light beams supplied from the plurality of input ports to the optical receiver, thereby enabling crosstalk of multiple cores to be measured with a small mounting area.

[0013] The optical time domain reflectometer according to one embodiment may further include a controller configured to generate an OTDR waveform based on the backscattered light detected by the optical receiver, thereby enabling checking of the crosstalk distribution along the longitudinal direction of the multi-core optical fiber.

[0014] The optical pulse tester according to one embodiment may further include a display unit that displays the OTDR waveform, thereby making it possible to easily check the OTDR waveform.

[0015] A measurement method according to some embodiments is a method for measuring crosstalk between cores of a multi-core optical fiber using an optical pulse tester, and includes the steps of generating an optical pulse, outputting the optical pulse from an output port to one core of a plurality of cores of the multi-core optical fiber, receiving at an input port backscattered light generated in cores other than the one core of the plurality of cores, and detecting the backscattered light received by the input port. According to this measurement method, it is possible to easily and accurately measure crosstalk between cores in a multi-core optical fiber. [Effects of the Invention]

[0016] According to the present disclosure, it is possible to provide an optical time domain tester and a measurement method that can easily and accurately measure crosstalk between cores in a multi-core optical fiber. [Brief explanation of the drawings]

[0017] [Figure 1]1 is a diagram showing a schematic configuration of an optical pulse tester according to a first embodiment. [Figure 2] FIG. 1 is a diagram showing an example of an OTDR waveform. [Figure 3] FIG. 10 is a diagram illustrating a schematic configuration of an optical pulse tester according to a second embodiment. [Figure 4] FIG. 1 is a diagram showing a schematic configuration of an optical pulse tester according to a comparative example. [Figure 5A] FIG. 10 is a diagram showing an example of an OTDR waveform affected by leakage from an optical directional coupler, measured by an optical time domain reflectometer according to a comparative example. [Figure 5B] FIG. 10 is a diagram showing an example of an OTDR waveform measured by an optical time domain reflectometer according to a comparative example, from which the influence of leakage from an optical directional coupler has been removed. DETAILED DESCRIPTION OF THE INVENTION

[0018] Hereinafter, embodiments of the present disclosure will be described with reference to the drawings.

[0019] (First embodiment) 1 is a diagram showing a schematic configuration of an optical pulse tester 10 according to the first embodiment. The configuration and functions of the optical pulse tester 10 according to the first embodiment will be described with reference to FIG.

[0020] The optical time domain tester 10 is a measuring instrument capable of measuring the crosstalk between cores of the multi-core optical fiber 1. The optical time domain tester 10 may be a measuring instrument capable of functioning as, for example, an OTDR (Optical Time Domain Reflectometer).

[0021] The multi-core optical fiber 1 to be measured is an optical fiber having multiple cores in one cladding. The multiple cores of the multi-core optical fiber 1 cause crosstalk between each core.

[0022] A multi-core optical fiber 1 to be measured is connected to an optical time domain reflectometer 10 via a fan-out 2. The fan-out 2 is an optical fiber element that converts the multiple cores of the multi-core optical fiber 1 into multiple single-core optical fibers. A single-core optical fiber is an optical fiber that has one core in one cladding.

[0023] 1, the fan-out 2 converts four cores of the multi-core optical fiber 1 into four single-core optical fibers. Note that the fan-out 2 converting into four single-core optical fibers is just an example, and the fan-out 2 may convert multiple cores of the multi-core optical fiber 1 into any number of single-core optical fibers equal to or greater than two.

[0024] Optical time domain tester 10 includes laser driver 11, laser element 12, photoreceivers 13-1 to 13-3, amplifier circuits 14-1 to 14-3, AD converters 15-1 to 15-3, control unit 16, display unit 17, output port 20, and input ports 30-1 to 30-3.

[0025] Hereinafter, when there is no need to distinguish between optical receivers 13-1 to 13-3, they will be simply referred to as optical receiver 13. Although optical time domain tester 10 includes three optical receivers 13-1 to 13-3 in FIG. 1, optical time domain tester 10 may include one or more optical receivers 13.

[0026] Hereinafter, when there is no need to particularly distinguish between the amplifier circuits 14-1 to 14-3, they will be simply referred to as amplifier circuit 14. Also, although the optical time domain tester 10 in FIG. 1 includes three amplifier circuits 14-1 to 14-3, it is sufficient for the optical time domain tester 10 to include one or more amplifier circuits 14.

[0027] Hereinafter, when there is no need to distinguish between AD converters 15-1 to 15-3, they will be simply referred to as AD converter 15. Although optical time domain tester 10 includes three AD converters 15-1 to 15-3 in FIG. 1, optical time domain tester 10 may include one or more AD converters 15.

[0028] Hereinafter, when there is no need to distinguish between input ports 30-1 to 30-3, they will be simply referred to as input port 30. In addition, although optical time domain tester 10 is shown in FIG. 1 to have three input ports 30-1 to 30-3, optical time domain tester 10 may have one or more input ports 30.

[0029] The laser driver 11 is a driving unit that drives the laser element 12. The laser driver 11 drives the laser element 12 in response to a command from the control unit 16, and can cause the laser element 12 to generate an optical pulse.

[0030] The laser element 12 generates laser light of a predetermined wavelength. The laser element 12 is driven by the laser driver 11 to generate optical pulses.

[0031] The optical pulse generated by the laser element 12 is output from the output port 20. The optical pulse output from the output port 20 is input to one of the multiple cores of the multi-core optical fiber 1 via the fan-out 2.

[0032] When an optical pulse is input to one of the multiple cores of the multi-core optical fiber 1, crosstalk occurs from the core to which the optical pulse is input to cores other than the core to which the optical pulse is input. Hereinafter, the "core to which the optical pulse is input" may be referred to as the "input core." Also, the "cores other than the core to which the optical pulse is input" may be referred to as the "other cores."

[0033] When an optical pulse is input to an input core, the optical pulse leaks to other cores due to crosstalk. When the optical pulse leaks to other cores, backscattered light is generated in the other cores. The backscattered light generated in the three other cores is output to input ports 30-1 to 30-3, respectively, via fan-out 2.

[0034] The input ports 30-1 to 30-3 receive the backscattered light generated in the three other cores, respectively.

[0035] The photoreceivers 13-1 to 13-3 are connected to the input ports 30-1 to 30-3, respectively. The photoreceiver 13-1 detects the backscattered light received by the input port 30-1. The photoreceiver 13-1 outputs a current signal corresponding to the optical intensity of the detected backscattered light to the amplifier circuit 14-1. The photoreceiver 13-2 detects the backscattered light received by the input port 30-2. The photoreceiver 13-2 outputs a current signal corresponding to the optical intensity of the detected backscattered light to the amplifier circuit 14-2. The photoreceiver 13-3 detects the backscattered light received by the input port 30-3. The photoreceiver 13-3 outputs a current signal corresponding to the optical intensity of the detected backscattered light to the amplifier circuit 14-3.

[0036] The light receiver 13 may be, for example, a photodiode.

[0037] The amplifier circuits 14-1 to 14-3 are connected to the photoreceivers 13-1 to 13-3, respectively. The amplifier circuit 14-1 converts the current signal supplied from the photoreceiver 13-1 into a voltage signal and amplifies the converted voltage signal. The amplifier circuit 14-1 outputs the amplified voltage signal to the AD converter 15-1. The amplifier circuit 14-2 converts the current signal supplied from the photoreceiver 13-2 into a voltage signal and amplifies the converted voltage signal. The amplifier circuit 14-2 outputs the amplified voltage signal to the AD converter 15-2. The amplifier circuit 14-3 converts the current signal supplied from the photoreceiver 13-3 into a voltage signal and amplifies the converted voltage signal. The amplifier circuit 14-3 outputs the amplified voltage signal to the AD converter 15-3.

[0038] The amplifier circuit 14 may be an amplifier circuit of any configuration.

[0039] AD converters 15-1 to 15-3 are connected to amplifier circuits 14-1 to 14-3, respectively. AD converter 15-1 samples the analog voltage signal supplied from amplifier circuit 14-1 at predetermined time intervals and converts it into a digital signal. AD converter 15-1 outputs the digital signal to control unit 16. AD converter 15-2 samples the analog voltage signal supplied from amplifier circuit 14-2 at predetermined time intervals and converts it into a digital signal. AD converter 15-2 outputs the digital signal to control unit 16. AD converter 15-3 samples the analog voltage signal supplied from amplifier circuit 14-3 at predetermined time intervals and converts it into a digital signal. AD converter 15-3 outputs the digital signal to control unit 16.

[0040] The AD converter 15 may be an AD converter of any configuration.

[0041] The control unit 16 includes at least one processor, at least one dedicated circuit, or a combination of these. The processor is a general-purpose processor such as a central processing unit (CPU) or a graphics processing unit (GPU), or a dedicated processor specialized for a specific process. The dedicated circuit is, for example, a field-programmable gate array (FPGA) or an application-specific integrated circuit (ASIC). The control unit 16 controls each component of the optical time domain tester 10 and executes processes related to the operation of the optical time domain tester 10.

[0042] The control unit 16 generates an OTDR waveform based on the digital signal supplied from the AD converter 15. Here, the digital signal supplied from the AD converter 15 is a signal corresponding to the light intensity of the backscattered light detected by the photodetector 13.

[0043] In this specification, "OTDR waveform" refers to a waveform in which the horizontal axis represents distance and the vertical axis represents light intensity. "Distance" refers to the distance from one end of the multi-core optical fiber 1 along the longitudinal direction of the multi-core optical fiber 1. Here, one end of the multi-core optical fiber 1 is the end on the side where an optical pulse is input. In the OTDR waveform, "distance" corresponds to the time from when an optical pulse is input into the multi-core optical fiber 1 until the backscattered light returns. In the OTDR waveform, "light intensity" corresponds to the light intensity of the backscattered light.

[0044] 2 shows an example of an OTDR waveform generated by the control unit 16. The control unit 16 generates an OTDR waveform for each of the digital signals supplied from the AD converters 15-1 to 15-3. That is, the control unit 16 generates three OTDR waveforms.

[0045] A user of the optical time domain tester 10 can check the distribution of crosstalk from the input core to the three other cores along the longitudinal direction of the multi-core optical fiber 1 by checking the OTDR waveform.

[0046] 1, when the optical time domain tester 10 has three input ports 30-1 to 30-3, the control unit 16 can simultaneously generate OTDR waveforms for the three other cores of the multi-core optical fiber 1. Therefore, when the optical time domain tester 10 has three input ports 30-1 to 30-3, the user of the optical time domain tester 10 can simultaneously check crosstalk to the three other cores.

[0047] The control unit 16 controls the laser driver 11 to cause the laser element 12 to generate an optical pulse. The control unit 16 can change the amplification degree of the amplifier circuit 14 in accordance with the light intensity of the backscattered light detected by the photodetector 13.

[0048] The display unit 17 includes one or more output interfaces for displaying information, and may include, for example, an LCD (Liquid Crystal Display) or an organic EL (Electro Luminescent) display.

[0049] The display unit 17 can display the OTDR waveform generated by the control unit 16.

[0050] According to the optical time domain reflectometer 10 of the first embodiment described above, it is possible to easily and accurately measure crosstalk between cores in the multi-core optical fiber 1. More specifically, the optical time domain reflectometer 10 includes an output port 20 that outputs an optical pulse to one of the multiple cores in the multi-core optical fiber 1, and an input port 30 that receives backscattered light generated in the cores other than the one of the multiple cores. Therefore, the optical time domain reflectometer 10 does not need to use an optical directional coupler to measure crosstalk, and is not affected by leakage of backscattered light from the core to which the optical pulse is input via the optical directional coupler. Therefore, the optical time domain reflectometer 10 can accurately measure crosstalk between cores in the multi-core optical fiber 1. Furthermore, the optical time domain reflectometer 10 can easily measure crosstalk using a single device by outputting an optical pulse from the output port 20 and receiving backscattered light at the input port 30.

[0051] 1, the optical time domain tester 10 according to the first embodiment may have multiple input ports 30. When multiple input ports 30 are provided, the optical time domain tester 10 according to the first embodiment can simultaneously measure the crosstalk of multiple other cores.

[0052] (Second embodiment) 3 is a diagram showing a schematic configuration of an optical pulse tester 10a according to the second embodiment. The configuration and functions of the optical pulse tester 10a according to the second embodiment will be described with reference to FIG.

[0053] The optical pulse tester 10a according to the second embodiment will be described mainly in terms of the differences from the optical pulse tester 10 according to the first embodiment, and descriptions of the commonalities or similarities with the optical pulse tester 10 according to the first embodiment will be omitted as appropriate.

[0054] The optical pulse tester 10a according to the second embodiment includes a laser driver 11, a laser element 12, a photodetector 13, an amplifier circuit 14, an AD converter 15, a control unit 16, a display unit 17, an optical switch 18, an output port 20, and input ports 30-1 to 30-3.

[0055] The optical pulse tester 10a according to the second embodiment differs from the optical pulse tester 10 according to the first embodiment in that it has only one optical receiver 13, one amplifier circuit 14, and one AD converter 15. The optical pulse tester 10a according to the second embodiment also differs from the optical pulse tester 10 according to the first embodiment in that it includes an optical switch 18.

[0056] The optical switch 18 is connected to the input ports 30-1 to 30-3. The optical switch 18 outputs to the photodetector 13 one of the plurality of backscattered lights supplied from the input ports 30-1 to 30-3.

[0057] The optical switch 18 may be an optical switch of any configuration that is capable of selecting and outputting one light beam from among a plurality of input light beams.

[0058] The control unit 16 controls the optical switch 18 to switch which of the multiple backscattered lights the optical switch 18 outputs to the light receiver 13 .

[0059] The optical time domain tester 10a according to the second embodiment can reduce the number of components because it requires only one optical receiver 13, one amplifier circuit 14, and one AD converter 15. Therefore, the optical time domain tester 10a according to the second embodiment can reduce the mounting area of ​​the optical receiver 13, the amplifier circuit 14, and the AD converter 15 on the circuit board.

[0060] Furthermore, the optical time domain reflectometer 10a according to the second embodiment can easily and accurately measure the crosstalk between cores in the multi-core optical fiber 1, similar to the optical time domain reflectometer 10 according to the first embodiment.

[0061] (Comparative Example) Fig. 4 is a diagram showing a schematic configuration of an optical time domain reflectometer 100 according to a comparative example. The optical time domain reflectometer 100 according to the comparative example will be described with reference to Fig. 4. The optical time domain reflectometer 100 according to the comparative example is also a measuring instrument capable of measuring crosstalk between cores of a multi-core optical fiber 1.

[0062] The optical pulse tester 100 of the comparative example includes a laser driver 11, a laser element 12, a photodetector 13, an amplifier circuit 14, an AD converter 15, a control unit 16, a display unit 17, an optical directional coupler 19, and an input / output port 40.

[0063] The optical directional coupler 19 is an optical element that transmits light in a specific direction. The optical directional coupler 19 outputs the optical pulse supplied from the laser element 12 to the input / output port 40. The optical directional coupler 19 also outputs the backscattered light supplied from the input / output port 40 to the photodetector 13.

[0064] The optical time domain tester 100 according to the comparative example is connected to the multi-core optical fiber 1 to be measured via the optical directional coupler 3 and the fan-out 2.

[0065] The fan-out 2 converts the four cores of the multi-core optical fiber 1 into a single-core optical fiber 200 and single-core optical fibers 301 to 303. The single-core optical fiber 200 is connected to an input core of the multi-core optical fiber 1. The single-core optical fibers 301 to 303 are connected to the other three cores of the multi-core optical fiber 1, respectively.

[0066] The optical directional coupler 3 is an optical element that transmits light in a specific direction. The optical directional coupler 3 inputs optical pulses supplied from the input / output port 40 of the optical time domain reflectometer 100 into the input core of the multi-core optical fiber 1 via the fan-out 2.

[0067] The optical directional coupler 3 can be connected to any one of the single-core optical fibers 301 to 303. The optical directional coupler 3 outputs the backscattered light supplied from the connected single-core optical fiber among the single-core optical fibers 301 to 303 to the input / output port 40 of the optical time domain tester 100.

[0068] 4 shows a state in which the single-core optical fiber 301 of the single-core optical fibers 301 to 303 is connected to the optical directional coupler 3. In this case, backscattered light generated by crosstalk in the other cores of the multi-core optical fiber 1 connected to the single-core optical fiber 301 is output to the input / output port 40 of the optical time domain tester 100.

[0069] The backscattered light received by the input / output port 40 from the optical directional coupler 3 is output to the optical receiver 13 by the optical directional coupler 19. The processing after the optical receiver 13 detects the backscattered light is the same as the processing of the optical time domain tester 10 according to the first embodiment.

[0070] When measuring the crosstalk between cores of the multi-core optical fiber 1 using the optical time domain reflectometer 100 according to the comparative example, the following problems arise.

[0071] When an optical pulse output from the input / output port 40 of the optical time domain tester 100 is input to an input core of the multi-core optical fiber 1, backscattered light is also generated in the input core. The backscattered light generated in the input core is input to the optical directional coupler 3 via the single-core optical fiber 200.

[0072] The optical directional coupler 3 does not normally output the backscattered light input from the single-core optical fiber 200 to the input / output port 40 of the optical time domain reflectometer 100. However, since the blocking ability of the optical directional coupler 3 is not perfect, a part of the backscattered light input from the single-core optical fiber 200 to the optical directional coupler 3 leaks out to the input / output port 40 of the optical time domain reflectometer 100.

[0073] As a result, the optical time domain tester 100 according to the comparative example ends up measuring the backscattered light from the input core leaking out of the optical directional coupler 3, added to the backscattered light from the other cores that are the original measurement targets.

[0074] FIG. 5A shows an example of an OTDR waveform measured by the optical pulse tester 100 according to the comparative example under this condition.

[0075] 5A, waveform 401 is an OTDR waveform obtained by measuring the backscattered light from the input core leaking out of the optical directional coupler 3 added to the backscattered light from other cores that are the original measurement target. Waveform 402 is an OTDR waveform obtained only by the backscattered light from the input core leaking out of the optical directional coupler 3.

[0076] In the optical time domain tester 100 according to the comparative example, it is also possible to eliminate the influence of backscattered light from the input core leaking out of the optical directional coupler 3. In this case, first, the OTDR waveform of the waveform 402 is measured in advance in a state where none of the single-core optical fibers 301 to 303 is connected, and the result is subtracted from the OTDR waveform of the waveform 401 measured in a state where the single-core optical fiber 301 is connected.

[0077] The OTDR waveform measured in this way, which is the original target of measurement, due to backscattered light from other cores, is shown in Figure 5B. The OTDR waveform in Figure 5B is the waveform that we actually want to measure.

[0078] However, when performing such a measurement, it is necessary to measure the OTDR waveform in advance with none of the single-core optical fibers 301 to 303 connected, which increases the number of measurements and requires the effort of connecting and disconnecting the single-core optical fiber 301. Furthermore, if the OTDR waveform is measured in advance with none of the single-core optical fibers 301 to 303 connected and the measurement result contains noise, the influence of the noise will appear when the previously measured OTDR waveform is subtracted, making it impossible to obtain a highly accurate measurement result.

[0079] Furthermore, in order to measure the crosstalk of all three other cores using the optical time domain reflectometer 100 according to the comparative example, it is necessary to reconnect the single-core optical fibers 301 to 303 and the optical directional coupler 3 for each measurement, and measure them in order. Therefore, the optical time domain reflectometer 100 according to the comparative example cannot measure the crosstalk of multiple other cores simultaneously.

[0080] In contrast, the optical time domain tester 10 according to the first embodiment and the optical time domain tester 10a according to the second embodiment each have an output port 20 and an input port 30 separately, so there is no need to install an optical directional coupler 3 between the fan-out 2.

[0081] Therefore, the optical time domain reflectometer 10 according to the first embodiment and the optical time domain reflectometer 10a according to the second embodiment can accurately measure crosstalk while completely eliminating the influence of backscattered light from the input core.

[0082] Furthermore, the optical time tester 10 according to the first embodiment and the optical time tester 10a according to the second embodiment do not need to measure the OTDR waveform in advance with none of the single-core optical fibers 301 to 303 connected, as is the case with the optical time tester 100 according to the comparative example. Therefore, the optical time tester 10 according to the first embodiment and the optical time tester 10a according to the second embodiment can measure crosstalk in a single measurement, and can measure crosstalk without the hassle of connecting and disconnecting the single-core optical fibers 301 to 303.

[0083] Furthermore, when the optical time domain tester 10 according to the first embodiment has a plurality of input ports 30 and optical receivers 13, the optical time domain tester 10 according to the first embodiment can simultaneously measure the crosstalk of a plurality of other cores, thereby enabling the crosstalk of a plurality of other cores to be measured in a short time.

[0084] It will be apparent to those skilled in the art that the present disclosure can be embodied in other specific forms other than the above-described embodiments without departing from the spirit or essential characteristics thereof. Therefore, the foregoing description is illustrative and not limiting. The scope of the disclosure is defined not by the foregoing description but by the appended claims. All modifications within the range of equivalents of any modifications are intended to be encompassed therein.

[0085] For example, the arrangement and number of the components described above are not limited to the above description and the illustrations in the drawings, and may be arbitrarily configured as long as the functions thereof can be realized.

[0086] For example, in the above-described embodiment, an example was given in which the number of input ports 30 was three, but the number of input ports 30 is not limited to this, and may be any number equal to or greater than one. [Explanation of symbols]

[0087] 1. Multi-core optical fiber 2. Fanout 3 Optical directional coupler 10, 10a Optical Time Domain Reflectometer 11 Laser driver 12 Laser element 13 Receiver 14 Amplification circuit 15 AD converter 16 Control Unit 17 Display 18 Optical Switch 19 Optical directional coupler 20 output ports 30 input ports 40 input / output ports 100 Optical Time Domain Reflectometer 200 Single-core optical fiber 301~303 Single-core optical fiber

Claims

1. An optical time domain reflectometer for measuring crosstalk between cores of a multi-core optical fiber, comprising: a laser element for generating optical pulses; an output port that outputs the optical pulse to one core out of a plurality of cores of the multi-core optical fiber; an input port for receiving backscattered light generated in a core other than the one core of the plurality of cores; a light receiver for detecting the backscattered light received by the input port; An optical time domain tester comprising:

2. 2. The optical pulse tester according to claim 1, An optical time domain reflectometer having a plurality of the input ports.

3. 3. The optical pulse tester according to claim 2, A plurality of the light receivers is provided, The optical time domain reflectometer includes a plurality of optical receivers connected to the plurality of input ports, respectively.

4. 3. The optical pulse tester according to claim 2, further comprising an optical switch connected to a plurality of said input ports; The optical switch outputs any one of the plurality of backscattered light beams supplied from the plurality of input ports to the optical receiver.

5. 2. The optical pulse tester according to claim 1, The optical time domain tester further comprises a control unit that generates an optical time domain reflectometer (OTDR) waveform based on the backscattered light detected by the optical receiver.

6. 6. The optical pulse tester according to claim 5, The optical time domain tester further comprises a display unit that displays the OTDR waveform.

7. A method for measuring crosstalk between cores of a multi-core optical fiber using an optical time domain reflectometer, comprising: generating a light pulse; outputting the optical pulse from an output port to one core of a plurality of cores of the multi-core optical fiber; receiving, at an input port, backscattered light generated in cores other than the one core of the plurality of cores; detecting the backscattered light received by the input port; , including, a measurement method.

8. 8. The measurement method according to claim 7, The optical time domain reflectometer includes a plurality of input ports.

9. 9. The measurement method according to claim 8, The optical time domain tester comprises: a plurality of light receivers for detecting the backscattered light; A measurement method, wherein the plurality of optical receivers are respectively connected to the plurality of input ports.

10. 9. The measurement method according to claim 8, The optical time domain tester comprises: further comprising an optical switch connected to a plurality of said input ports; The optical switch outputs any one of the plurality of backscattered lights supplied from the plurality of input ports.

11. 8. The measurement method according to claim 7, The measurement method further includes generating an OTDR waveform based on the detected backscattered light.

12. The measurement method according to claim 11, The measurement method further comprises the step of displaying the OTDR waveform.

Images