Optical pulse tester and measurement method

Abstract

The present invention relates to an optical pulse tester and a measurement method for easily and accurately measuring crosstalk between cores of a multi-core optical fiber. An optical pulse tester (10) measures crosstalk between cores of a multi-core optical fiber (1). An optical pulse tester (10) is provided with: a laser element (12) that generates an optical pulse; an output port (20) that outputs an optical pulse to one of the plurality of cores of the multi-core optical fiber (1); an input port (30) that receives backscattered light generated in a core other than one of the plurality of cores; and a light receiver (13) that detects the backscattered light received by the input port (30).

Description

Technical Field

[0001] The present invention relates to an optical pulse tester and a measuring method. Background Art

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

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

[0004] Currently, various technologies are being studied as techniques for measuring crosstalk between cores of a multi-core optical fiber. For example, Patent Document 1 discloses a technique for measuring crosstalk using a plurality of OTDR (Optical Time Domain Reflectometer) devices.

[0005] Patent Document 1: Japanese Patent Application Laid-Open No. 2012-202827 Summary of the Invention

[0006] The measurement method described in Patent Document 1 requires the use of a plurality of OTDR devices, and cannot easily measure the crosstalk between cores of a multi-core optical fiber.

[0007] Another method for measuring crosstalk between cores in a multi-core optical fiber is to input a light pulse into one of the multiple cores via an optical directional coupler, and then receive and measure the backscattered light generated in the other cores via the same optical directional coupler. With this measurement method, the optical directional coupler's blocking capability is incomplete, so the backscattered light from the core to which the light pulse was input leaks through the optical directional coupler and overlaps with the backscattered light generated in the other cores. Therefore, it is difficult to measure only the backscattered light generated in the other cores, making it difficult to accurately measure crosstalk.

[0008] Therefore, an object of the present invention is to provide an optical pulse tester and a measurement method capable of easily and accurately measuring crosstalk between cores of a multi-core optical fiber.

[0009] Several embodiments relate to an optical pulse tester for measuring crosstalk between cores of a multi-core optical fiber. The optical pulse tester comprises: a laser element for generating optical pulses; an output port for outputting the optical pulses to one of the multiple cores of the multi-core optical fiber; an input port for receiving backscattered light generated in cores other than the one core of the multiple cores; and a light receiver for detecting the backscattered light received by the input port. This optical pulse tester enables easy and highly accurate measurement of crosstalk between cores of the multi-core optical fiber.

[0010] In one embodiment, the optical pulse tester may include a plurality of input ports, thereby being able to simultaneously receive a plurality of backscattered lights.

[0011] In one embodiment, the optical pulse tester may include a plurality of the light receivers, each of which is connected to the plurality of input ports, thereby enabling simultaneous measurement of crosstalk between a plurality of cores.

[0012] In one embodiment, the optical pulse tester may further include an optical switch connected to the plurality of input ports, the optical switch outputting any one of the plurality of backscattered lights supplied from the plurality of input ports to the light receiver. This allows crosstalk measurements of multiple cores to be performed with a small mounting area.

[0013] The optical pulse tester according to one embodiment may further include a control unit that generates an OTDR waveform based on the backscattered light detected by the optical receiver. This allows confirmation of the distribution of crosstalk along the length of the multi-core optical fiber.

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

[0015] Several embodiments provide a method for measuring crosstalk between cores of a multi-core optical fiber using an optical pulse tester. The method comprises the following steps: generating an optical pulse; outputting the optical pulse from an output port to one of the multiple cores of the multi-core optical fiber; receiving backscattered light generated in cores other than the one of the multiple cores at an input port; and detecting the backscattered light received at the input port. This method allows for easy and highly accurate measurement of crosstalk between cores of the multi-core optical fiber.

[0016] Effects of the Invention

[0017] According to the present invention, it is possible to provide an optical pulse tester and a measurement method capable of easily and accurately measuring crosstalk between cores of a multi-core optical fiber. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] Figure 1 This is a diagram showing a schematic configuration of an optical pulse tester according to the first embodiment.

[0019] Figure 2 This is a diagram showing an example of an OTDR waveform.

[0020] Figure 3 This is a diagram showing a schematic configuration of an optical pulse tester according to a second embodiment.

[0021] Figure 4 It is a diagram showing a schematic configuration of an optical pulse tester according to a comparative example.

[0022] Figure 5A This is a diagram showing an example of an OTDR waveform measured in an optical pulse tester according to a comparative example and affected by leakage from an optical directional coupler.

[0023] Figure 5B This is a diagram showing an example of an OTDR waveform measured by an optical pulse tester according to a comparative example, in which the influence of leakage from an optical directional coupler is eliminated. DETAILED DESCRIPTION

[0024] Hereinafter, embodiments of the present invention will be described with reference to the accompanying drawings.

[0025] (First embodiment)

[0026] Figure 1 1 is a diagram showing a schematic configuration of an optical pulse tester 10 according to the first embodiment. Figure 1 The structure and function of the optical pulse tester 10 according to the first embodiment will be described.

[0027] The optical pulse tester 10 is a measuring device capable of measuring crosstalk between cores of the multi-core optical fiber 1. The optical pulse tester 10 may be a measuring device capable of functioning as an OTDR (Optical Time Domain Reflectometer), for example.

[0028] The multi-core optical fiber 1 to be measured is an optical fiber having a plurality of cores in a single cladding. The plurality of cores of the multi-core optical fiber 1 generate crosstalk between the cores.

[0029] The multi-core optical fiber 1 to be measured is connected to an optical pulse tester 10 via a fan-out 2. The fan-out 2 is an optical fiber component 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 having one core in one cladding.

[0030] exist Figure 1 In the example shown, the fan-out unit 2 converts the four cores of the multi-core optical fiber 1 into four single-core optical fibers. Furthermore, the conversion of the fan-out unit 2 into four single-core optical fibers is merely an example, and the fan-out unit 2 can also convert the multiple cores of the multi-core optical fiber 1 into any number of single-core optical fibers, greater than or equal to two.

[0031] The optical pulse tester 10 includes a laser driver 11, a laser element 12, photoreceivers 13-1 to 13-3, amplifier circuits 14-1 to 14-3, AD converters 15-1 to 15-3, a control unit 16, a display unit 17, an output port 20, and input ports 30-1 to 30-3.

[0032] Hereinafter, when there is no need to distinguish between the light receivers 13-1 to 13-3, they will be simply referred to as the light receiver 13. Figure 1 In FIG. 1 , the optical pulse tester 10 includes three light receivers 13 - 1 to 13 - 3 , but the optical pulse tester 10 only needs to include one or more light receivers 13 .

[0033] Hereinafter, when there is no need to distinguish between the amplifier circuits 14-1 to 14-3, they will be simply referred to as the amplifier circuit 14. Figure 1 In FIG. 1 , the optical pulse tester 10 includes three amplifier circuits 14 - 1 to 14 - 3 , but the optical pulse tester 10 only needs to include one or more amplifier circuits 14 .

[0034] Hereinafter, when there is no need to distinguish between the AD converters 15-1 to 15-3, they will be simply referred to as the AD converter 15. Figure 1 In FIG. 1 , the optical pulse tester 10 includes three AD converters 15 - 1 to 15 - 3 , but the optical pulse tester 10 only needs to include one or more AD converters 15 .

[0035] Hereinafter, when there is no need to distinguish between the input ports 30-1 to 30-3, they will be simply referred to as input ports 30. Figure 1 In FIG. 3 , the optical pulse tester 10 has three input ports 30 - 1 to 30 - 3 , but the optical pulse tester 10 only needs to have one input port 30 or more.

[0036] The laser driver 11 is a driving unit that drives the laser element 12. The laser driver 11 drives the laser element 12 according to a command from the control unit 16, and can cause the laser element 12 to generate a light pulse.

[0037] The laser element 12 generates laser light of a predetermined wavelength and is driven by the laser driver 11 to generate light pulses.

[0038] 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 cores of the multi-core optical fiber 1 via the fan-out unit 2 .

[0039] When a light pulse is input into one of the multiple cores of a multi-core optical fiber 1, crosstalk occurs from the core into which the light pulse is input to cores other than the core into which the light pulse is input. Hereinafter, the "core into which the light pulse is input" will sometimes be referred to as the "input core." Furthermore, the "cores other than the core into which the light pulse is input" will sometimes be referred to as "other cores."

[0040] When a light pulse is input to the input core, it leaks out to other cores due to crosstalk. This leakage generates backscattered light in the other cores. The backscattered light generated in the three other cores is output to input ports 30-1 through 30-3 via fan-out element 2.

[0041] The input ports 30 - 1 to 30 - 3 receive backscattered light generated in the other three cores, respectively.

[0042] Photoreceivers 13-1 to 13-3 are connected to input ports 30-1 to 30-3, respectively. Photoreceiver 13-1 detects backscattered light received at input port 30-1. Photoreceiver 13-1 outputs a current signal corresponding to the intensity of the detected backscattered light to amplifier circuit 14-1. Photoreceiver 13-2 detects backscattered light received at input port 30-2. Photoreceiver 13-2 outputs a current signal corresponding to the intensity of the detected backscattered light to amplifier circuit 14-2. Photoreceiver 13-3 detects backscattered light received at input port 30-3. Photoreceiver 13-3 outputs a current signal corresponding to the intensity of the detected backscattered light to amplifier circuit 14-3.

[0043] The light receiver 13 may be, for example, a photodiode.

[0044] Amplifier circuits 14-1 to 14-3 are connected to photoreceivers 13-1 to 13-3, respectively. Amplifier circuit 14-1 converts the current signal supplied from photoreceiver 13-1 into a voltage signal and amplifies the converted voltage signal. Amplifier circuit 14-1 outputs the amplified voltage signal to A / D converter 15-1. Amplifier circuit 14-2 converts the current signal supplied from photoreceiver 13-2 into a voltage signal and amplifies the converted voltage signal. Amplifier circuit 14-2 outputs the amplified voltage signal to A / D converter 15-2. Amplifier circuit 14-3 converts the current signal supplied from photoreceiver 13-3 into a voltage signal and amplifies the converted voltage signal. Amplifier circuit 14-3 outputs the amplified voltage signal to A / D converter 15-3.

[0045] The amplifier circuit 14 may be an amplifier circuit of any structure.

[0046] 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.

[0047] The AD converter 15 may be an AD converter of any structure.

[0048] The control unit 16 includes at least one processor, at least one dedicated circuit, or a combination thereof. The processor can be a general-purpose processor such as a CPU (Central Processing Unit) or a GPU (Graphics Processing Unit), or a dedicated processor that performs specialized processing. The dedicated circuit can be, for example, an FPGA (Field-Programmable Gate Array) or an ASIC (Application-Specific Integrated Circuit). The control unit 16 controls various components of the optical pulse tester 10 and executes processing related to the operation of the optical pulse tester 10.

[0049] 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 optical receiver 13.

[0050] In this specification, an "OTDR waveform" refers to a waveform with distance on the horizontal axis and light intensity on the vertical axis. "Distance" is the distance along the length of multi-core fiber 1, starting from one end. Here, the one end of multi-core fiber 1 is the end on the side where the light pulse is input. In an OTDR waveform, "distance" corresponds to the time from the time a light pulse is injected into multi-core fiber 1 until the backscattered light returns. In an OTDR waveform, "light intensity" corresponds to the intensity of the backscattered light.

[0051] exist Figure 2 1 shows an example of an OTDR waveform generated by the control unit 16. The control unit 16 generates OTDR waveforms 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.

[0052] The user of the optical pulse tester 10 can confirm 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.

[0053] like Figure 1 As shown, when the optical pulse 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 pulse tester 10 has three input ports 30-1 to 30-3, the user of the optical pulse tester 10 can simultaneously check crosstalk to the three other cores.

[0054] The control unit 16 controls the laser driver 11 to generate light pulses in the laser element 12. 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 light receiver 13.

[0055] 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.

[0056] The display unit 17 can display the OTDR waveform generated by the control unit 16 .

[0057] According to the optical pulse tester 10 involved in the first embodiment as described above, the crosstalk between the cores of the multi-core optical fiber 1 can be measured easily and with high precision. More specifically, the optical pulse tester 10 has: an output port 20, which outputs an optical pulse to one of the multiple cores of the multi-core optical fiber 1; and an input port 30, which receives backscattered light generated in the cores other than the one of the multiple cores. Therefore, the optical pulse tester 10 does not need to use an optical directional coupler to measure the crosstalk, and is not affected by the backscattered light from the core to which the optical pulse is input leaking through the optical directional coupler. Therefore, the optical pulse tester 10 can measure the crosstalk between the cores of the multi-core optical fiber 1 with high precision. In addition, the optical pulse tester 10 outputs the optical pulse from the output port 20 and receives the backscattered light at the input port 30, so that the crosstalk can be easily measured in one device.

[0058] In addition, if Figure 1 As shown, the optical pulse tester 10 according to the first embodiment may include a plurality of input ports 30. When the optical pulse tester 10 according to the first embodiment includes a plurality of input ports 30, it is possible to measure the crosstalk of a plurality of other cores simultaneously.

[0059] (Second embodiment)

[0060] Figure 3 : is a diagram showing a schematic configuration of an optical pulse tester 10a according to a second embodiment. Figure 3 The structure and function of the optical pulse tester 10 a according to the second embodiment will be described.

[0061] The optical pulse tester 10 a according to the second embodiment will be described mainly with respect to differences from the optical pulse tester 10 according to the first embodiment, and description of aspects common to or similar to the optical pulse tester 10 according to the first embodiment will be appropriately omitted.

[0062] An optical pulse tester 10 a according to the second embodiment includes a laser driver 11 , a laser element 12 , a light receiver 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 .

[0063] The optical pulse tester 10a according to the second embodiment differs from the optical pulse tester 10 according to the first embodiment in that the optical receiver 13, the amplifier circuit 14, and the A / D converter 15 are all one. Furthermore, 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 includes an optical switch 18.

[0064] The optical switch 18 is connected to the input ports 30 - 1 to 30 - 3 , and outputs any one of the plurality of backscattered lights supplied from the input ports 30 - 1 to 30 - 3 to the light receiver 13 .

[0065] The optical switch 18 may be an optical switch of any structure capable of selecting and outputting any one of a plurality of input light beams.

[0066] The control unit 16 controls the optical switch 18 to switch which of the plurality of backscattered lights the optical switch 18 outputs to the light receiver 13 .

[0067] The optical pulse tester 10a according to the second embodiment can be configured to include only one optical receiver 13, one amplifier circuit 14, and one A / D converter 15, thereby reducing the number of components. Consequently, the optical pulse tester 10a according to the second embodiment can reduce the mounting area of ​​the optical receiver 13, the amplifier circuit 14, and the A / D converter 15 on the circuit board.

[0068] Furthermore, the optical pulse tester 10 a according to the second embodiment can measure the crosstalk between the cores of the multi-core optical fiber 1 easily and with high accuracy, similarly to the optical pulse tester 10 according to the first embodiment.

[0069] (Comparative Example)

[0070] Figure 4 1 is a diagram showing a schematic configuration of an optical pulse tester 100 according to a comparative example. Figure 4 The optical pulse tester 100 according to the comparative example will be described. The optical pulse tester 100 according to the comparative example is also a measuring device capable of measuring crosstalk between cores of the multi-core optical fiber 1 .

[0071] The optical pulse tester 100 according to the comparative example includes a laser driver 11 , a laser element 12 , a light receiver 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 .

[0072] The optical directional coupler 19 is an optical element that transmits light in a specific direction. The optical directional coupler 19 outputs the light 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 light receiver 13.

[0073] An optical pulse tester 100 according to the comparative example is connected to a multi-core optical fiber 1 as a measurement target via an optical directional coupler 3 and a fan-out unit 2 .

[0074] The fan-out unit 2 converts the four cores of the multi-core optical fiber 1 into single-core optical fibers 200 and single-core optical fibers 301 to 303. The single-core optical fiber 200 is connected to the 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.

[0075] The optical directional coupler 3 is an optical element that transmits light in a specific direction and inputs an optical pulse supplied from the input / output port 40 of the optical pulse tester 100 into the input core of the multi-core optical fiber 1 via the fan-out unit 2 .

[0076] The optical directional coupler 3 can be connected to any of the single-core fibers 301 to 303 . The optical directional coupler 3 outputs backscattered light supplied from the connected single-core fiber among the single-core fibers 301 to 303 to the input / output port 40 of the optical pulse tester 100 .

[0077] Figure 4 The figure shows a case where single-core fiber 301 among single-core fibers 301 to 303 is connected to optical directional coupler 3. In this case, backscattered light generated by crosstalk in other cores of multi-core fiber 1 connected to single-core fiber 301 is output to input / output port 40 of optical pulse tester 100.

[0078] 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 that of the optical pulse tester 10 according to the first embodiment.

[0079] When measuring the crosstalk between cores of the multi-core optical fiber 1 using the optical pulse tester 100 according to the comparative example, the following problems arise.

[0080] When the optical pulse output from the input / output port 40 of the optical pulse tester 100 is input to the input core of the multi-core optical fiber 1 , backscattered light is also generated in the input core 1 . The backscattered light generated in the input core is input to the optical directional coupler 3 via the single-core optical fiber 200 .

[0081] The optical directional coupler 3 originally does not output backscattered light input from the single-core optical fiber 200 to the input / output port 40 of the optical pulse tester 100. However, the optical directional coupler 3 does not have a complete blocking capability, so a portion of the backscattered light input from the single-core optical fiber 200 to the optical directional coupler 3 leaks to the input / output port 40 of the optical pulse tester 100.

[0082] Then, the optical pulse tester 100 according to the comparative example measures light obtained by superimposing backscattered light from the input core leaking from the optical directional coupler 3 and backscattered light from other cores that are originally the measurement target.

[0083] Figure 5A 2 shows an example of an OTDR waveform measured by the optical pulse tester 100 according to the comparative example in this state.

[0084] exist Figure 5A In FIG. 4 , waveform 401 is the OTDR waveform obtained when measuring light obtained by superimposing backscattered light from the input core that leaks from the optical directional coupler 3 and backscattered light from the other cores originally being measured. Waveform 402 is the OTDR waveform obtained based solely on backscattered light from the input core that leaks from the optical directional coupler 3.

[0085] The optical pulse tester 100 according to the comparative example can also eliminate the influence of backscattered light from the input core that leaks from the optical directional coupler 3. In this case, first, an OTDR waveform of waveform 402 is measured in advance with none of the single-core optical fibers 301 to 303 connected. This result is then subtracted from the OTDR waveform of waveform 401 measured with the single-core optical fiber 301 connected.

[0086] Figure 5B The OTDR waveform obtained by the measurement based on the backscattered light from the other core that is originally the measurement target is shown in FIG. Figure 5B The OTDR waveform is the waveform to be measured.

[0087] However, when performing such measurements, the OTDR waveform must be measured beforehand without connecting any of the single-core optical fibers 301 to 303. This increases the number of measurements and increases the time required to connect or disconnect the single-core optical fiber 301. Furthermore, if the OTDR waveform is measured beforehand without connecting any of the single-core optical fibers 301 to 303, and if noise is present in the measurement result, the influence of the noise will be apparent when the pre-measured OTDR waveform is subtracted, thus failing to achieve a highly accurate measurement result.

[0088] Furthermore, in order to measure the crosstalk of all three other cores using the optical pulse tester 100 according to the comparative example, the single-core optical fibers 301 to 303 and the optical directional coupler 3 must be reconnected and measured sequentially each time a measurement is performed. Therefore, the optical pulse tester 100 according to the comparative example cannot simultaneously measure the crosstalk of multiple other cores.

[0089] In contrast, the optical pulse tester 10 according to the first embodiment and the optical pulse tester 10 a according to the second embodiment each have the output port 20 and the input port 30 , and therefore do not require an optical directional coupler 3 to be provided between the fan-out element 2 .

[0090] Therefore, the optical pulse tester 10 according to the first embodiment and the optical pulse tester 10 a according to the second embodiment can measure crosstalk with high accuracy while completely eliminating the influence of backscattered light from the input core.

[0091] Furthermore, the optical pulse tester 10 according to the first embodiment and the optical pulse tester 10a according to the second embodiment do not require the OTDR waveform to be measured beforehand without connecting any of the single-core optical fibers 301 to 303, as required by the optical pulse tester 100 according to the comparative example. Therefore, the optical pulse tester 10 according to the first embodiment and the optical pulse tester 10a according to the second embodiment can measure crosstalk in a single measurement, eliminating the time and effort required to connect and disconnect the single-core optical fibers 301 to 303.

[0092] Furthermore, when the optical pulse tester 10 according to the first embodiment has multiple input ports 30 and multiple optical receivers 13 , the optical pulse tester 10 according to the first embodiment can simultaneously measure the crosstalk of multiple other cores, thereby enabling the crosstalk of multiple other cores to be measured in a short time.

[0093] Those skilled in the art will appreciate that the present invention can be implemented in other prescribed ways besides the above-described embodiments without departing from its spirit or essential characteristics. Therefore, the above description is for illustrative purposes only and is not intended to be limiting. The scope of the disclosure is not defined by the above description but by the accompanying technical solutions. All variations within the scope of their equivalents are intended to be included herein.

[0094] For example, the arrangement and number of the above-mentioned components are not limited to those in the above description and drawings, and can be configured arbitrarily as long as the arrangement and number of the components can achieve their functions.

[0095] For example, in the above embodiment, the case where the number of input ports 30 is three is taken as an example for description. However, the number of input ports 30 is not limited thereto and may be any number greater than or equal to one.

[0096] Description of the label

[0097] 1 Multi-core fiber

[0098] 2 fan-outs

[0099] 3 Optical directional coupler

[0100] 10, 10a optical pulse tester

[0101] 11 Laser Driver

[0102] 12 Laser Components

[0103] 13 Photoreceiver

[0104] 14 Amplifier Circuit

[0105] 15 AD converter

[0106] 16 Control Unit

[0107] 17 Display

[0108] 18 Optical Switch

[0109] 19 Optical directional coupler

[0110] 20 output ports

[0111] 30 input ports

[0112] 40 input and output ports

[0113] 100 Optical Pulse Tester

[0114] 200 single-core optical fiber

[0115] 301~303 single-core optical fiber

Claims

1. An optical pulse tester for measuring crosstalk between cores of a multi-core optical fiber, wherein: The optical pulse tester has: a laser element that generates light pulses; an output port configured to output the optical pulse to one of the plurality of cores of the multi-core optical fiber; an input port for receiving backscattered light generated in cores other than the one core of the plurality of cores; as well as A light receiver detects the backscattered light received by the input port.

2. The optical pulse tester according to claim 1, wherein: The optical pulse tester has a plurality of input ports.

3. The optical pulse tester according to claim 2, wherein: The optical pulse tester includes a plurality of light receivers. The plurality of light receivers are connected to the plurality of input ports, respectively.

4. The optical pulse tester according to claim 2, wherein: The optical pulse tester further includes an optical switch connected to the plurality of input ports. The optical switch outputs any one of the plurality of backscattered lights supplied from the plurality of input ports to the light receiver.

5. The optical pulse tester according to claim 1, wherein: The optical pulse tester further includes a control unit that generates an OTDR waveform based on the backscattered light detected by the light receiver. The OTDR is an optical fiber time domain reflectometer.

6. The optical pulse tester according to claim 5, wherein: The optical pulse tester further includes a display unit for displaying the OTDR waveform.

7. A method for measuring crosstalk between cores of a multi-core optical fiber using an optical pulse tester, wherein: The determination method comprises the following steps: generating light pulses; Outputting the optical pulse from the output port to one core among the multiple cores of the multi-core optical fiber; receiving, through an input port, backscattered light generated in cores other than the one core of the plurality of cores; as well as The backscattered light received by the input port is detected.

8. The measuring method according to claim 7, wherein The optical pulse tester has a plurality of input ports.

9. The measuring method according to claim 8, wherein The optical pulse tester includes a plurality of light receivers for detecting the backscattered light. The plurality of light receivers are connected to the plurality of input ports, respectively.

10. The measuring method according to claim 8, wherein The optical pulse tester further includes an optical switch connected to the plurality of input ports. The optical switch outputs any one of the plurality of backscattered lights supplied from the plurality of input ports.

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

12. The measuring method according to claim 11, wherein The measuring method further includes the step of displaying the OTDR waveform.

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