A fiber and optical modem connection testing device, method and system

Abstract

This invention discloses a fiber optic and optical modem connection testing device, method, and system. The testing device includes a fiber bending module, a first photoelectric detection module, a signal amplifier, an ADC module, a timing control circuit, an FPGA control logic module, a return loss measurement access port, a laser, and a second photoelectric detection module. The FPGA control logic module includes a burst light detection unit and a return loss measurement unit. This invention will not cause network outages for users and can accurately determine whether an optical splitter port is connected to an optical modem, providing data support for clearing unused ports.

Description

Technical Field

[0001] This invention relates to optical fiber communication testing technology, and more particularly to a testing device, method and system for the connection testing of optical fiber and optical modem. Background Technology

[0002] Optical fiber, as the primary transmission medium for modern internet communication, boasts advantages such as high data transmission rates and low signal attenuation, leading to a surge in users adopting fiber optic networks for communication. Typically, each building is equipped with a fiber distribution box containing a splitter. The splitter's input ports connect to an optical line terminal (OLT), while it has multiple output ports that connect to individual optical modems (ODMs) via the drop fiber. An ODM, also known as a single-port optical transceiver or optical modem, modulates optical signals into electrical signals, enabling computers and other devices to understand and process them. Therefore, monitoring the connection status between the drop fiber and the ODM is fundamental to ensuring communication quality.

[0003] In reality, when fiber optic network users relocate their broadband service or change network operators, the original network system is typically "soft-disconnected" (network shutdown). Installation and maintenance personnel don't need to make a second on-site visit to remove the existing fiber optic connection. Furthermore, the fiber distribution box contains numerous and mixed ports; if the wrong port is connected to, another user already using the fiber optic network, it can cause network outages and complaints. If a new user is added, a new splitter is installed, and the new user's optical modem is connected to the new splitter's wired transmission port. The port previously connected to the splitter remains connected to the fiber optic cable, but the fiber optic cable is not connected to the optical modem, resulting in a port being "idled." Over time, the idling rate of the splitter increases, causing significant resource waste, while adding more splitters also increases costs.

[0004] To detect whether the drop fiber from the port of an optical splitter is connected to an optical modem, current technology typically uses a PON network tester for fiber disconnection testing. This involves unplugging the drop fiber from the splitter port and testing whether the fiber is currently connected. This process requires testing while the fiber is disconnected (network interruption), and incorrect disconnection can still cause network outages for users. Furthermore, the PON network tester uses the conventional Twisted-Back-Loss Measurement (OTDR) method for fiber disconnection testing to determine if an optical modem is connected. This method requires both peak power and starting power for calculation. However, in optical modem testing applications, due to the complexity of actual optical paths and stringent dead zone requirements, the starting power is often unavailable. Consequently, the traditional OTDR method cannot accurately measure the emissivity value, and therefore cannot accurately determine whether an optical modem is connected to the splitter port. Summary of the Invention

[0005] To address the problems existing in the prior art, the purpose of this invention is to provide a connection testing device, method, and system that can accurately determine whether a splitter's port is connected to an optical modem without causing network outages for users. It can quickly identify and clear unused pigtails, release unused port resources, significantly save investment, and has high economic benefits.

[0006] To achieve the above-mentioned objectives, the present invention provides the following technical solution:

[0007] A fiber optic and optical modem connection testing device includes a fiber bending module, a first photoelectric detection module, a signal amplifier, an ADC module, a timing control circuit, an FPGA control logic module, a return loss measurement access port, a laser, and a second photoelectric detection module. The FPGA control logic module includes a burst light detection unit and a return loss measurement unit, wherein:

[0008] The fiber bending module is used to bend the drop fiber to a preset radius, thereby leaking the optical signal transmitted in the drop fiber to the outer layer of the drop fiber.

[0009] The first photoelectric detection module is located near the fiber bending module and close to the outer layer of the incoming fiber. It is used to detect burst light signals leaking from the outer layer of the incoming fiber and to perform photoelectric conversion.

[0010] The signal amplifier and ADC module are used to amplify the received electrical signal and perform digital conversion;

[0011] The timing control circuit is used to perform envelope detection on the digital electrical signal of the burst optical signal to obtain the complete pulse of the burst optical signal;

[0012] The burst light detection unit is used to calculate the pulse interval between complete pulses of the burst light signal detected by the timing control circuit within a preset time period, and calculate the average value of all complete pulses based on the pulse interval. If the average value is greater than the preset ratio of the noise signal, it is determined that there is a burst light signal in the fiber optic cable; otherwise, it is determined that there is no burst light signal in the fiber optic cable.

[0013] The return loss measurement access port is used to connect to the fiber optic cable to the home.

[0014] The laser is used to emit laser light into the access fiber optic cable.

[0015] The second photoelectric detection module is used to receive the echo signal reflected back from the emitted laser and convert it into an electrical signal;

[0016] The return loss measurement unit is used to receive the echo signal digital electrical signal obtained after processing by the signal amplifier and the ADC module, calculate the reflectivity value of the echo signal according to the following formula, and determine whether the optical fiber to the home is connected to an optical modem based on the reflectivity value:

[0017] RL = RL ref -(P onu -P ref )

[0018] In the formula, RL is the reflectivity value of the echo signal. ref As a preset reference reflectivity, P onu P represents the peak reflected power of the echo signal. ref This is the preset reference reflection power peak value.

[0019] Furthermore, the first photoelectric detection module includes two photodetectors, each with a filter film coated on its window. The filter film allows only burst light signals with wavelengths of 1270nm and 1310nm to pass through, while isolating light signals of other wavelengths.

[0020] Furthermore, the device also includes a display screen, an MCU, and a button module. The display screen, the button module, and the FPGA control logic module are all connected to the MCU. The MCU is used to receive trigger signals sent by the button module, generate corresponding instructions and send them to the corresponding modules, and display the judgment results of the FPGA control logic module and other test results on the display screen.

[0021] Furthermore, the return loss measurement unit specifically includes:

[0022] The receiving subunit is used to receive the echo signal digital electrical signal obtained after processing by the signal amplifier and the ADC module;

[0023] The reflected power peak calculation subunit is used to calculate the reflected power peak P of the echo signal based on the digital electrical signal of the echo signal. onu ;

[0024] The reflectivity calculation subunit is used to calculate the reflectivity value of the echo signal according to the following formula:

[0025] RL = RL ref -(P onu -P ref )

[0026] The determination subunit is used to determine whether the incoming fiber optic cable is connected to an optical modem based on the reflectivity value according to the following rules:

[0027] When RL ≥ the first preset threshold, the fiber optic cable to the home is not connected to an optical modem;

[0028] When the second preset threshold ≤ RL ≤ the first preset threshold, the fiber optic cable to the home is connected to an optical modem.

[0029] When RL ≤ the second preset threshold, the fiber optic cable to the home is broken.

[0030] A method for testing the connection between an optical fiber and an optical modem, the method being implemented based on the aforementioned testing apparatus, specifically includes the following steps:

[0031] S1. Connect the analysis terminal to the testing device described in claim 1;

[0032] S2. With the fiber optic cable connected to the splitter port, place the fiber optic cable inside the fiber bending module and perform burst light detection on the fiber optic cable. When the burst light detection unit obtains the burst light detection result, it sends the burst light detection result to the analysis terminal.

[0033] S3. When the burst light detection result shows that there is a burst light signal in the drop fiber, the analysis terminal determines that the drop fiber is connected to an optical modem, records the splitter port connected to the drop fiber as in use, and uploads it to the resource management center; otherwise, proceed to step S4.

[0034] S4. Unplug the fiber optic cable from the splitter and insert it into the return loss measurement access port to perform return loss measurement. When the return loss measurement unit obtains the judgment result of whether the fiber optic cable is connected to the optical modem based on the reflectivity value, it sends the connection judgment result to the analysis terminal.

[0035] S5. The analysis terminal determines the incoming optical fiber that is not connected to the optical modem as a dummy port optical fiber, updates the splitter port connected to the dummy port optical fiber to the dummy state, and uploads it to the resource center; it determines the incoming optical fiber that is connected to the optical modem as an access state, updates the splitter port connected to the incoming optical fiber to the in-use state, and uploads it to the resource center.

[0036] S6. The resource center stores the status of all optical splitter ports.

[0037] A fiber optic and optical modem connection testing system includes the aforementioned testing device, analysis terminal, and resource center, wherein:

[0038] The testing device is used to perform burst light detection on the drop fiber when it is placed inside the fiber bending module, with the drop fiber connected to the splitter port; and to send the burst light detection result to the analysis terminal when the burst light detection unit obtains the burst light detection result. It also performs return loss measurement when the drop fiber is unplugged from the splitter and inserted into the return loss measurement access port, and sends the connection determination result to the analysis terminal when the return loss measurement unit obtains the determination result of whether the drop fiber is connected to an optical modem based on the reflectivity value.

[0039] The analysis terminal is used to, upon receiving burst light detection results, determine if the drop fiber is connected to an optical modem when the burst light detection result indicates a burst light signal in the drop fiber, record the splitter port connected to the drop fiber as in use, and upload it to the resource management center; and upon receiving connection judgment results, determine if the drop fiber is not connected to an optical modem as a dummy port fiber, update the splitter port connected to the dummy port fiber to a dummy state, and upload it to the resource center; and determine if the drop fiber is connected to an optical modem as in access state, update the splitter port connected to the drop fiber to an in use state, and upload it to the resource center.

[0040] The resource center is used to store the status of all optical splitter ports.

[0041] Compared with the prior art, the beneficial effects of this invention are:

[0042] 1. This invention first uses burst light detection to preliminarily determine whether the fiber optic cable to the home is in use. If it is not in use, the fiber is then disconnected for echo detection, which will not cause network outages for users who are currently using the network.

[0043] 2. This invention uses a timing control circuit for envelope detection and burst light detection units, which enables burst light detection of weak signals and improves the accuracy of detection.

[0044] 3. The return loss measurement unit of this invention uses the reference calibration method to calculate the reflectivity value, which eliminates the need to accurately obtain the starting power and further improves the accuracy of detection;

[0045] 4. The photodetector of the present invention uses coating technology to filter burst light, which reduces the difficulty of subsequent signal processing, reduces burst light signal detection error, and further improves the accuracy of burst light detection.

[0046] 5. The fiber optic and optical modem connection testing device, method and system of the present invention can quickly identify and clear unused pigtails, release unused port resources, greatly save investment and have high economic benefits. Attached Figure Description

[0047] Figure 1 This is a schematic diagram of the structure of the fiber optic and optical modem connection testing device provided by the present invention;

[0048] Figure 2 This is a schematic diagram of the structure of the fiber bending module and the first photoelectric detection module provided by the present invention;

[0049] Figure 3 This is a diagram showing the filtering characteristics of the filter film of the photodetector provided by the present invention;

[0050] Figure 4 This is a schematic diagram of the burst optical signal provided by the present invention;

[0051] Figure 5 This is a schematic diagram of the return loss measurement access port provided by the present invention;

[0052] Figure 6 This is a schematic diagram of reflectivity calculation provided by the present invention;

[0053] Figure 7 This is a flowchart illustrating the connection testing method between an optical fiber and an optical modem provided by the present invention. Detailed Implementation

[0054] The technical solutions of the present invention will be clearly and completely described below with reference to the accompanying drawings in the embodiments of the present invention.

[0055] Example 1

[0056] This invention provides a connection testing device for optical fiber and optical modem, such as... Figure 1 As shown, it includes an optical fiber bending module, a first photoelectric detection module, a signal amplifier, an ADC module, a timing control circuit, an FPGA control logic module, a return loss measurement access port, a laser, and a second photoelectric detection module. The FPGA control logic module includes a burst light detection unit and a return loss measurement unit, wherein:

[0057] The fiber bending module is used to bend the drop fiber to a preset radius, thereby leaking the optical signal transmitted in the drop fiber to the outer layer of the drop fiber.

[0058] The first photoelectric detection module is located near the fiber bending module and close to the outer layer of the incoming fiber. It is used to detect burst light signals leaking from the outer layer of the incoming fiber and to perform photoelectric conversion.

[0059] The signal amplifier and ADC module are used to amplify the received electrical signal and perform digital conversion;

[0060] The timing control circuit is used to perform envelope detection on the digital electrical signal of the burst optical signal to obtain the complete pulse of the burst optical signal;

[0061] The burst light detection unit is used to calculate the pulse interval between complete pulses of the burst light signal detected by the timing control circuit within a preset time period, and calculate the average value of all complete pulses based on the pulse interval. If the average value is greater than the preset ratio of the noise signal, it is determined that there is a burst light signal in the fiber optic cable; otherwise, it is determined that there is no burst light signal in the fiber optic cable.

[0062] The return loss measurement access port is used to connect to the fiber optic cable to the home.

[0063] The laser is used to emit laser light into the access fiber optic cable.

[0064] The second photoelectric detection module is used to receive the echo signal reflected back from the emitted laser and convert it into an electrical signal;

[0065] The return loss measurement unit is used to receive the echo signal digital electrical signal obtained after processing by the signal amplifier and the ADC module, calculate the reflectivity value of the echo signal according to the following formula, and determine whether the optical fiber to the home is connected to an optical modem based on the reflectivity value:

[0066] RL = RL ref -(P onu -P ref )

[0067] In the formula, RL is the reflectivity value of the echo signal. ref As a preset reference reflectivity, P onu P represents the peak reflected power of the echo signal. ref This is the preset reference reflection power peak value.

[0068] To improve the usability of the testing device, the device may also include a display screen, an MCU, and a button module. The display screen, the button module, and the FPGA control logic module are all connected to the MCU. The button module may include power on and off buttons for the device, power on and off buttons for burst light detection, and power on and off buttons for return loss measurement. The MCU is used to receive trigger signals sent by the button module, generate corresponding instructions and send them to the corresponding modules, and display the judgment results of the FPGA control logic module and other test results on the display screen. For example, it may display the result of whether there is a burst light signal in the drop fiber, the specific value of the burst light signal, the reflectivity value of the echo signal, and the judgment result of whether the drop fiber is connected to an optical modem.

[0069] like Figure 2 As shown, the fiber bending module includes an upper clamping member 1 and a lower clamping member 2. The upper clamping member 1 has a protrusion with a radius of the preset radius below it, and the lower clamping member 2 has a recess with a radius of the preset radius above it. The upper clamping member 1 and the lower clamping member 2 are tightly fitted together. When the incoming fiber 3 is clamped between the upper clamping member 1 and the lower clamping member 2, the incoming fiber can be bent to the preset radius. The total internal reflection characteristic of the incoming fiber is destroyed, and some burst optical signals transmitted inside will leak to the outer layer of the fiber and be received by the first photodetector module composed of photodetectors P1 and P2.

[0070] It should be noted that in other embodiments, the fiber bending module can also be configured with other shapes or other configurations. For example, the fiber bending module can be configured as a groove with a radius of the preset radius, and placing the incoming fiber in the groove can also achieve bending the incoming fiber to the preset radius.

[0071] Since the optical signal to be detected in this invention originates from an optical modem, but optical fibers in a PON network contain both uplink and downlink optical signals, the wavelengths of the uplink and downlink optical signals are as follows: In EPON / GPON networks, the uplink optical signal wavelength is 1310nm, and the downlink optical signal wavelength is 1490nm; in XGPON networks, the uplink optical signal wavelength is 1270nm, and the downlink optical signal wavelength is 1577nm. Ordinary photodetectors are made of InGaAs material, with a wavelength response range of approximately 700-1700nm. Clearly, detecting all uplink and downlink signals would affect the judgment. Therefore, in this embodiment, a filter film is coated on the windows of photodetectors P1 and P2, allowing only uplink optical signals with wavelengths of 1270nm and 1310nm to pass through, isolating other wavelengths of optical signals, thus solving this problem. Because the uplink optical signal emitted by the optical modem in a PON network is time-division multiplexed, meaning each optical modem occupies only one time slot of the OLT, the uplink optical signal is an intermittent burst signal. Figure 3 This is a diagram showing the filtering characteristics of the filter films coated on the windows of photodetectors P1 and P2.

[0072] According to the XGPON protocol specification, the shortest frame length for a burst optical signal is 10ns. Therefore, the duration of a leaked burst optical signal is very short, only 10-200ns. During this time, the burst optical signal is not entirely high-level, but a combination of high and low levels, such as... Figure 4 As shown. Furthermore, the leakage light intensity is very weak, approximately -50dBm. In addition, the interval between leaked burst light signals varies under different environments, sometimes 125µs, sometimes 1ms, making burst light signals very difficult to identify and detect, resulting in a high false positive rate. To solve this problem, this invention synchronizes the uplink time slot interval of the timing controller to 125µs, and then performs envelope detection to obtain the complete pulse of the burst light signal within one polling cycle, as shown. Figure 4 As shown in red. Then, the burst light detection unit calculates the pulse interval between complete pulses of the burst light signal detected by the timing control circuit within a preset time period (e.g., 100ms), and calculates the average value of all complete pulses based on the pulse interval. If the average value is greater than the preset proportion of the noise signal (e.g., 20%), it is determined that there is a burst light signal in the drop fiber; otherwise, it is determined that there is no burst light signal in the drop fiber.

[0073] A burst of optical signal on the drop fiber indicates that the fiber is in use and connected to an optical modem. If there is no burst of optical signal, it means the drop fiber is currently unused, but it's unclear whether the optical modem is not connected or connected but not powered on. In this case, return loss measurement can be used to determine the cause. Specifically, since the drop fiber is currently unused, it can be unplugged from the port and then plugged into the return loss measurement input port T1, as shown below. Figure 5 As shown, the laser is controlled to emit laser light into the access fiber optic cable, and the reflectivity of the echo signal is measured.

[0074] The calculation and judgment of the echo signal reflectivity value are realized through the echo detection unit, which specifically includes:

[0075] The receiving subunit is used to receive the echo signal digital electrical signal obtained after processing by the signal amplifier and the ADC module;

[0076] The reflected power peak calculation subunit is used to calculate the reflected power peak P of the echo signal based on the digital electrical signal of the echo signal. onu ;

[0077] The reflectivity calculation subunit is used to calculate the reflectivity value of the echo signal according to the following formula:

[0078] RL = RL ref -(P onu -P ref )

[0079] In the formula, RL is the reflectivity value of the echo signal. ref As a preset reference reflectivity, P onu P represents the peak reflected power of the echo signal. ref RL is the preset reference reflection power peak value. ref For the preset reference reflectivity and P ref The specific peak value of the preset reference reflection power can be obtained through testing, such as... Figure 6 As shown;

[0080] The determination subunit is used to determine whether the incoming fiber optic cable is connected to an optical modem based on the reflectivity value according to the following rules:

[0081] When RL ≥ the first preset threshold (-20dBm), the fiber optic cable to the home is not connected to an optical modem;

[0082] When the second preset threshold (-40dBm) ≤ RL ≤ the first preset threshold (-20dBm), the fiber optic cable to the home is connected to an optical modem.

[0083] When RL ≤ the second preset threshold (-40dBm), the fiber optic cable to the home is broken.

[0084] This invention uses a reference calibration method to calculate reflectivity values, which can accurately calculate reflectivity values ​​without requiring a starting power.

[0085] Example 2

[0086] This embodiment provides a method for testing the connection between an optical fiber and an optical modem. This method is based on the testing device described in Embodiment 1 above. Figure 7 As shown, the method specifically includes the following steps:

[0087] S1. Connect the analysis terminal to the testing device described in claim 1 via communication, such as Bluetooth connection or wired connection;

[0088] S2. With the fiber optic cable connected to the splitter port, place the fiber optic cable inside the fiber bending module and perform burst light detection on the fiber optic cable. When the burst light detection unit obtains the burst light detection result, it sends the burst light detection result to the analysis terminal.

[0089] S3. When the burst light detection result shows that there is a burst light signal in the drop fiber, the analysis terminal determines that the drop fiber is connected to an optical modem, records the splitter port connected to the drop fiber as in use, and uploads it to the resource management center; otherwise, proceed to step S4.

[0090] S4. Unplug the fiber optic cable from the splitter and insert it into the return loss measurement access port to perform return loss measurement. When the return loss measurement unit obtains the judgment result of whether the fiber optic cable is connected to the optical modem based on the reflectivity value, it sends the connection judgment result to the analysis terminal.

[0091] S5. The analysis terminal determines the incoming optical fiber that is not connected to the optical modem as a dummy port optical fiber, updates the splitter port connected to the dummy port optical fiber to the dummy state, and uploads it to the resource center; it determines the incoming optical fiber that is connected to the optical modem as an access state, updates the splitter port connected to the incoming optical fiber to the in-use state, and uploads it to the resource center.

[0092] S6. The resource center stores the status of all optical splitter ports.

[0093] The analysis terminal can be an app on a smartphone, tablet, or other smart mobile device. Besides status assessment and data forwarding, the analysis terminal can also perform analysis and statistical functions to facilitate viewing the status of the optical splitter ports. It can also receive data or instructions from the resource center, such as viewing all optical splitter ports in a vacant state, clearing the incoming fiber optic cables connected to these vacant ports, updating the splitter ports to an available state, and then reporting to the resource center. The resource center can store the status of all optical splitter ports, perform statistical analysis of their status, and send the status of the splitter ports to the analysis terminal, instructing the clearing of vacant ports, etc.

[0094] It should be noted that, where conditions permit, the analysis terminal can also be integrated with the testing device into a single device, that is, by adding corresponding hardware modules and software programs to the testing device, thereby realizing the functions that the analysis terminal can perform.

[0095] Example 3

[0096] This invention provides a fiber optic and optical modem connection testing system, including the testing device, analysis terminal, and resource center described in Embodiment 1, wherein:

[0097] The testing device is used to perform burst light detection on the drop fiber when it is placed inside the fiber bending module, with the drop fiber connected to the splitter port; and to send the burst light detection result to the analysis terminal when the burst light detection unit obtains the burst light detection result. It also performs return loss measurement when the drop fiber is unplugged from the splitter and inserted into the return loss measurement access port, and sends the connection determination result to the analysis terminal when the return loss measurement unit obtains the determination result of whether the drop fiber is connected to an optical modem based on the reflectivity value.

[0098] The analysis terminal is used to, upon receiving burst light detection results, determine if the drop fiber is connected to an optical modem when the burst light detection result indicates a burst light signal in the drop fiber, record the splitter port connected to the drop fiber as in use, and upload it to the resource management center; and upon receiving connection judgment results, determine if the drop fiber is not connected to an optical modem as a dummy port fiber, update the splitter port connected to the dummy port fiber to a dummy state, and upload it to the resource center; and determine if the drop fiber is connected to an optical modem as in access state, update the splitter port connected to the drop fiber to an in use state, and upload it to the resource center.

[0099] The resource center is used to store the status of all optical splitter ports.

[0100] The analysis terminal can be an app on a smartphone, tablet, or other smart mobile device. Besides status assessment and data forwarding, the analysis terminal can also perform analysis and statistical functions to facilitate viewing the status of the optical splitter ports. It can also receive data or instructions from the resource center, such as viewing all optical splitter ports in a vacant state, clearing the incoming fiber optic cables connected to these vacant ports, updating the splitter ports to an available state, and then reporting to the resource center. The resource center can store the status of all optical splitter ports, perform statistical analysis of their status, and send the status of the splitter ports to the analysis terminal, instructing the clearing of vacant ports, etc.

[0101] It should be noted that, where conditions permit, the analysis terminal can also be integrated with the testing device into a single device, that is, by adding corresponding hardware modules and software programs to the testing device, thereby realizing the functions that the analysis terminal can perform.

[0102] It should be understood that the embodiments and descriptions above are only the principles, main features and advantages of the present invention. Various changes and modifications can be made to the present invention without departing from the spirit and scope of the invention, and all such changes and modifications fall within the protection scope of the present invention.

Claims

1. A connection testing device for optical fiber and optical modem, characterized in that, The system includes an optical fiber bending module, a first photoelectric detection module, a signal amplifier, an ADC module, a timing control circuit, an FPGA control logic module, a return loss measurement access port, a laser, and a second photoelectric detection module. The FPGA control logic module includes a burst light detection unit and a return loss measurement unit. The fiber bending module is used to bend the drop fiber to a preset radius, thereby leaking the optical signal transmitted in the drop fiber to the outer layer of the drop fiber. The first photoelectric detection module is located near the fiber bending module and close to the outer layer of the incoming fiber. It is used to detect burst light signals leaking from the outer layer of the incoming fiber and to perform photoelectric conversion. The signal amplifier and ADC module are used to amplify the received electrical signal and perform digital conversion; The timing control circuit is used to perform envelope detection on the digital electrical signal of the burst optical signal to obtain the complete pulse of the burst optical signal; The burst light detection unit is used to calculate the pulse interval between complete pulses of the burst light signal detected by the timing control circuit within a preset time period, and calculate the average value of all complete pulses based on the pulse interval. If the average value is greater than the preset ratio of the noise signal, it is determined that there is a burst light signal in the fiber optic cable; otherwise, it is determined that there is no burst light signal in the fiber optic cable. The return loss measurement access port is used to connect to the fiber optic cable to the home. The laser is used to emit laser light into the access fiber optic cable. The second photoelectric detection module is used to receive the echo signal reflected back from the emitted laser and convert it into an electrical signal; The return loss measurement unit is used to receive the echo signal digital electrical signal obtained after processing by the signal amplifier and the ADC module, calculate the reflectivity value of the echo signal according to the following formula, and determine whether the optical fiber to the home is connected to an optical modem based on the reflectivity value: RL=RL ref -(P onu -P ref ) In the formula, RL is the reflectivity value of the echo signal. ref As a preset reference reflectivity, P onu P represents the peak reflected power of the echo signal. ref This is the preset reference reflection power peak value.

2. The fiber optic and optical modem connection testing device according to claim 1, characterized in that, The first photoelectric detection module includes two photodetectors, each with a filter film coated on its window. The filter film allows only burst light signals with wavelengths of 1270nm and 1310nm to pass through, while isolating light signals of other wavelengths.

3. The fiber optic and optical modem connection testing device according to claim 1, characterized in that, The device also includes a display screen, an MCU, and a button module. The display screen, the button module, and the FPGA control logic module are all connected to the MCU. The MCU is used to receive trigger signals sent by the button module, generate corresponding instructions and send them to the corresponding modules, and display the judgment results of the FPGA control logic module and other test results on the display screen.

4. The fiber optic and optical modem connection testing device according to claim 1, characterized in that, The return loss measurement unit specifically includes: The receiving subunit is used to receive the echo signal digital electrical signal obtained after processing by the signal amplifier and the ADC module; The reflected power peak calculation subunit is used to calculate the reflected power peak P of the echo signal based on the digital electrical signal of the echo signal. onu ; The reflectivity calculation subunit is used to calculate the reflectivity value of the echo signal according to the following formula: RL=RL ref -(P onu -P ref ) The determination subunit is used to determine whether the incoming fiber optic cable is connected to an optical modem based on the reflectivity value according to the following rules: When RL ≥ the first preset threshold, the fiber optic cable to the home is not connected to an optical modem; When the second preset threshold ≤ RL ≤ the first preset threshold, the fiber optic cable to the home is connected to an optical modem. When RL ≤ the second preset threshold, the fiber optic cable to the home is broken.

5. The connection test method for optical fiber and optical modem according to claim 4, characterized in that, The first preset threshold is -20dBm, and the second preset threshold is -40dBm.

6. The fiber optic and optical modem connection testing device according to claim 1, characterized in that, The timing control circuit synchronizes the uplink time slot interval to 125µs when performing envelope detection.

7. The fiber optic and optical modem connection testing device according to claim 1, characterized in that, The second photoelectric detection module is specifically an avalanche photodiode.

8. A method for testing the connection between an optical fiber and an optical modem, characterized in that, This method is implemented based on the testing apparatus described in claim 1, and specifically includes the following steps: S1. Connect the analysis terminal to the testing device described in claim 1; S2. With the fiber optic cable connected to the splitter port, place the fiber optic cable inside the fiber bending module and perform burst light detection on the fiber optic cable. When the burst light detection unit obtains the burst light detection result, it sends the burst light detection result to the analysis terminal. S3. When the burst light detection result shows that there is a burst light signal in the drop fiber, the analysis terminal determines that the drop fiber is connected to an optical modem, records the splitter port connected to the drop fiber as in use, and uploads it to the resource management center; otherwise, proceed to step S4. S4. Unplug the fiber optic cable from the splitter and insert it into the return loss measurement access port to perform return loss measurement. When the return loss measurement unit obtains the judgment result of whether the fiber optic cable is connected to the optical modem based on the reflectivity value, it sends the connection judgment result to the analysis terminal. S5. The analysis terminal determines the incoming optical fiber that is not connected to the optical modem as a dummy port optical fiber, updates the splitter port connected to the dummy port optical fiber to the dummy state, and uploads it to the resource center; it determines the incoming optical fiber that is connected to the optical modem as an access state, updates the splitter port connected to the incoming optical fiber to the in-use state, and uploads it to the resource center. S6. The resource center stores the status of all optical splitter ports.

9. The connection test method for optical fiber and optical modem according to claim 8, characterized in that, The method further includes: The analysis terminal stores, statistically analyzes, and records the status of the splitter ports.

10. A fiber optic and optical modem connection testing system, characterized in that, Includes the testing device, analysis terminal, and resource center as described in claim 1, wherein: The testing device is used to perform burst light detection on the drop fiber when it is placed inside the fiber bending module, with the drop fiber connected to the splitter port; and to send the burst light detection result to the analysis terminal when the burst light detection unit obtains the burst light detection result. It also performs return loss measurement when the drop fiber is unplugged from the splitter and inserted into the return loss measurement access port, and sends the connection determination result to the analysis terminal when the return loss measurement unit obtains the determination result of whether the drop fiber is connected to an optical modem based on the reflectivity value. The analysis terminal is used to, upon receiving burst light detection results, determine if the drop fiber is connected to an optical modem when the burst light detection result indicates a burst light signal in the drop fiber, record the splitter port connected to the drop fiber as in use, and upload it to the resource management center; and upon receiving connection judgment results, determine if the drop fiber is not connected to an optical modem as a dummy port fiber, update the splitter port connected to the dummy port fiber to a dummy state, and upload it to the resource center; and determine if the drop fiber is connected to an optical modem as in access state, update the splitter port connected to the drop fiber to an in use state, and upload it to the resource center. The resource center is used to store the status of all optical splitter ports.

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