CN116519265A

CN116519265A - Apparatus and method for optical fiber quality monitoring

Info

Publication number: CN116519265A
Application number: CN202210077991.8A
Authority: CN
Inventors: 黄建民; 孔凡华; 王元武
Original assignee: Huawei Technologies Co Ltd
Current assignee: Huawei Technologies Co Ltd
Priority date: 2022-01-24
Filing date: 2022-01-24
Publication date: 2023-08-01
Also published as: WO2023138114A1

Abstract

The present disclosure relates to apparatus and methods for fiber quality monitoring. The optical fiber quality monitoring device includes: a laser light source configured to emit a plurality of probe lights in a time-division manner; an optical transmission selection device coupled to the laser source and the plurality of optical fibers and configured to transmit the plurality of probe lights received from the laser source to the plurality of optical fibers in different directions, respectively, such that one optical fiber correspondingly receives one probe light; and an optical receiver coupled to the optical transmission selection device and configured to process a plurality of reflected and/or scattered light from the plurality of optical fibers received from the optical transmission selection device so as to enable monitoring of the quality of each of the plurality of optical fibers.

Description

Apparatus and method for optical fiber quality monitoring

Technical Field

The present disclosure relates to the field of optical fiber quality monitoring, and more particularly to an apparatus and method for optical fiber quality monitoring.

Background

In an optical transmission network system, an optical fiber is used to carry traffic signals of a subscriber. The problems of aging, external damage, curling, bending at a large angle, bearing large tension and the like of the optical fiber can cause the increase of optical fiber attenuation, the increase of service error rate and even the interruption of service, thereby affecting the normal operation of the network.

Therefore, monitoring the quality of the optical fiber is very important. For example, if the quality of the fiber cannot be detected during the cable construction stage, service may not be available in the future; likewise, if the quality of the optical fiber cannot be monitored in the network operation and maintenance stage, the fault point cannot be determined after the optical fiber fault occurs, the fault cannot be repaired in time, and the service is damaged for a long time.

Disclosure of Invention

It is an object of the present disclosure to provide an improved optical fiber quality monitoring device that enables quality monitoring of each of a plurality of optical fibers at least in parallel and in real time.

According to a first aspect of the present disclosure, there is provided an optical fiber quality monitoring apparatus. The optical fiber quality monitoring device includes: a laser light source configured to emit a plurality of probe lights in a time-division manner; an optical transmission selection device coupled to the laser source and the plurality of optical fibers and configured to transmit the plurality of probe lights received from the laser source to the plurality of optical fibers in different directions, respectively, such that one optical fiber correspondingly receives one probe light; and an optical receiver coupled to the optical transmission selection device and configured to process a plurality of reflected and/or scattered light from the plurality of optical fibers received from the optical transmission selection device so as to enable monitoring of the quality of each of the plurality of optical fibers.

With the optical fiber quality monitoring apparatus of the present disclosure, it is possible to emit a plurality of detection lights in a time-division manner, and monitoring of quality for each of a plurality of optical fibers can be achieved by monitoring a plurality of reflected and/or scattered lights from the plurality of optical fibers. In this way, not only can the mass of each of the plurality of optical fibers be monitored in parallel and in real time, but the optical fiber mass monitoring device also has the advantages of small volume and low cost.

In some embodiments, the laser source is further configured to repeatedly emit the plurality of probe lights in the time-division manner at a predetermined period. In these embodiments, multiple probe lights may thus be periodically emitted into multiple optical fibers, such that collection and monitoring of multiple reflected and/or scattered lights for each optical fiber may be achieved.

In some embodiments, each of the probe lights has an emission duration, and the emission durations of the plurality of probe lights are identical to each other. In this way, control of the laser source can be simplified.

In some embodiments, the predetermined period may be equal to the emission duration times the number of the plurality of probe lights. According to this design, the emission of a plurality of probe lights for a plurality of optical fibers can be realized with the shortest period.

In some embodiments, the transmission duration is at least 10ms. The 10ms duration threshold allows the emission of probe light suitable for monitoring with a short duration.

In some embodiments, the number of the plurality of probe lights is the same as the number of the plurality of optical fibers, and the number of the plurality of optical fibers is in a range of 2 to 32.

In some embodiments, the optical receiver is further configured to: monitoring of the quality of each optical fiber is achieved based on processing at least 300 reflected and/or scattered light received from the optical transmission selection device for each optical fiber. By processing at least 300 reflected and/or scattered light, a higher accuracy of quality monitoring of each fiber can be achieved.

In some embodiments, further comprising an optical circulator disposed between the laser source and the optical transmission selection device and further configured to: transmitting the plurality of detection light to the light transmission selection device, and reflecting the plurality of reflected and/or scattered light to the light receiver. In this way, a more compact construction of the optical fiber quality monitoring device can be achieved.

In some embodiments, the dominant wavelengths of any two of the plurality of probe lights are different from each other, and the light transmission selection device is 1: an n-filter or an optical switch, where n is equal to the number of the plurality of optical fibers. In still other embodiments, the dominant wavelengths in the plurality of probe lights are the same, and the light transmission selection device is an optical switch. In these embodiments, the appropriate optical transmission selection device may be selected according to the wavelength requirements.

According to a second aspect of the present disclosure, there is provided a method of monitoring quality of an optical fiber, comprising: emitting a plurality of probe lights in a time division manner using a laser source; transmitting the plurality of detection lights received from the laser source to a plurality of optical fibers in different directions, respectively, using a light transmission selection device, such that one optical fiber correspondingly receives one detection light; and processing the plurality of reflected and/or scattered light from the plurality of optical fibers received from the optical transmission selection device with an optical receiver to enable monitoring of the quality of each of the plurality of optical fibers.

In some embodiments, emitting the plurality of probe lights in a time division manner with the laser light source includes: the plurality of detection lights are repeatedly emitted in the time-division manner with a predetermined period by the laser light source.

In some embodiments, wherein processing the plurality of reflected and/or scattered light from the plurality of optical fibers received from the optical transmission selection device with an optical receiver comprises:

monitoring of the quality of each optical fiber is achieved based on processing at least 300 reflected and/or scattered light received from the optical transmission selection device for each optical fiber.

In some embodiments, the dominant wavelengths of any two of the plurality of probe lights are different from each other, and the light transmission selection device is 1: an n-filter or an optical switch, where n is equal to the number of the plurality of optical fibers.

In some embodiments, the dominant wavelengths in the plurality of probe lights are the same, and the light transmission selection device is an optical switch.

In some embodiments, an optical circulator is used to transmit the plurality of probe light to the optical transmission selection device and to reflect the plurality of reflected and/or scattered light to the optical receiver

According to a third aspect of the present disclosure, there is provided an optical communication device for an optical fiber, comprising the optical fiber quality monitoring device according to the first aspect.

It should also be appreciated that the descriptions in this summary are not intended to limit key or critical features of embodiments of the disclosure, nor are they intended to limit the scope of the disclosure. Other features of embodiments of the present disclosure will become apparent from the following description.

Drawings

The above and other features, advantages and aspects of embodiments of the present disclosure will become more apparent by reference to the following detailed description when taken in conjunction with the accompanying drawings. In the drawings, wherein like or similar reference numerals denote like or similar elements, in which:

FIG. 1 shows a schematic diagram of fiber quality monitoring using a separate optical time domain reflectometer;

FIG. 2 shows a schematic diagram of fiber quality monitoring using an on-line optical time domain reflectometer module;

FIG. 3 illustrates a schematic diagram of a fiber quality monitoring device according to an example embodiment of the present disclosure;

fig. 4 shows that the optical fiber quality monitoring device of the present disclosure has a configuration of 1: a transmission timing diagram of a plurality of probe lights emitted in a gap time division manner in the case of an n-filter;

fig. 5 shows that the optical fiber quality monitoring device of the present disclosure has a configuration of 1: a schematic diagram of the timing of the reception of the plurality of reflected and/or scattered light received in the case of an n-filter;

FIG. 6 illustrates an example of an application of the optical fiber quality monitoring device of the present disclosure in an optical communication device; and

fig. 7 shows a flowchart of a fiber quality monitoring method according to an example embodiment of the present disclosure.

Detailed Description

Embodiments of the present disclosure will be described in more detail below with reference to the accompanying drawings. While certain embodiments of the present disclosure have been shown in the accompanying drawings, it is to be understood that the present disclosure may be embodied in various forms and should not be construed as limited to the embodiments set forth herein, but are provided to provide a more thorough and complete understanding of the present disclosure. It should be understood that the drawings and embodiments of the present disclosure are for illustration purposes only and are not intended to limit the scope of the present disclosure.

As previously mentioned, monitoring of the quality of the optical fiber is important, whether during the cable construction phase or during the network operation phase. For monitoring the quality of the optical fiber, it is usually done based on the principle of Optical Time Domain Reflectometry (OTDR). Specifically, the optical signal emitted from one end of the optical fiber may generate rayleigh scattering and/or fresnel reflection during the optical fiber propagation, and based on the reflected and/or scattered light received at the one end of the optical fiber, detection of faults such as optical fiber length, transmission attenuation, joint attenuation, and the like may be achieved, and the location of the fault may be determined.

Common OTDR-based devices are e.g. with a separate optical time domain reflectometer (i.e. OTDR meter). Fig. 1 shows a schematic diagram of fiber quality monitoring using a separate optical time domain reflectometer. As shown in fig. 1, the fiber can be accessed to the separate OTDR meter, and then monitoring of the fiber quality is achieved. It is easy to understand that the individual OTDR instrument is more suitable for acceptance test of the quality of the optical fiber, because the optical fiber is not yet put into service during the acceptance test, so that the optical fiber is not taken out of the optical transmission equipment to be a problem; for maintenance testing, on-line monitoring is required, because the service may not be interrupted when the optical fiber fails, and the optical fiber cannot be directly pulled out of the optical transmission device to be connected to the OTDR instrument. Therefore, the on-line detection under the premise of not influencing the service cannot be realized by the separate OTDR instrument.

Fig. 2 shows a schematic diagram of fiber quality monitoring using an online on-line OTDR module. As shown in fig. 2, the OTDR module may be integrated into a tributary device of the optical communication device. During monitoring, the OTDR module may emit probe light having a characteristic wavelength (referred to as OTDR wavelength) different from the service wavelength, which may then be combined with the signal of the service wavelength for transmission in the optical fiber in parallel. Likewise, the quality of the fiber may be detected based on the principles of OTDR, e.g. detecting the magnitude and position of the fiber loss variations. In addition, the detection data can be reported to a network manager, so that the remote monitoring of the quality of the optical fiber is realized. The online-with-OTDR module has two significant advantages over an individual OTDR meter: a. the quality of the optical fiber can be monitored remotely in a network management center without entering a machine room, so that the fault positioning efficiency is greatly improved; b. the quality of the optical fiber can be detected on line, and the service is not affected when the quality of the optical fiber is detected.

However, online on-line OTDR solutions have several drawbacks:

1. cost: it requires that each of the plurality of optical fibers accessed by the optical transmission device be configured with an OTDR module that does not share devices, which results in high costs;

2. architecture: because an OTDR module/board card needs to be configured in the optical communication equipment for each optical fiber accessed, the equipment space occupied by the OTDR module/board card is large;

3. non-real time: the OTDR module typically also performs other functions such as communication of an Optical Supervisory Channel (OSC), which are affected by the OTDR function, so that the module cannot be monopolized by the OTDR function for a long time, and thus cannot be monitored in real time. Typical detection times for the on-line OTDR solution are around 5 minutes, meaning that the result of this OTDR detection is the fiber quality state 5 minutes ago.

It is an object of the present disclosure to provide an improved optical fiber quality monitoring apparatus and method that can at least enable parallel and real-time monitoring of the optical fiber quality of each of a plurality of optical fibers accessed. To this end, the concept of the present disclosure is: the method comprises the steps of transmitting a plurality of detection lights in a time division manner by using a laser source, selecting an appropriate optical transmission selection device to transmit the plurality of detection lights transmitted in the time division manner to a plurality of connected optical fibers respectively along different directions, and then processing a plurality of reflected and/or scattered lights from the plurality of optical fibers by using an optical receiver so as to realize the quality monitoring of each optical fiber in the plurality of optical fibers. In this way, it is possible to monitor the mass of each of the plurality of optical fibers in parallel and in real time, but the optical fiber mass monitoring apparatus has the advantages of small volume and low cost.

Fig. 3 shows a schematic structural diagram of a fiber quality monitoring apparatus 100 according to an example embodiment of the present disclosure.

As shown in fig. 3, the optical fiber quality monitoring apparatus 100 may mainly include a laser source 10, an optical transmission selecting device 20, and an optical receiver 30. It will be appreciated that with this structural arrangement of the optical fiber quality monitoring device 100, the optical fiber quality monitoring device 100 of the present disclosure may either be self-contained in a manner similar to the OTDR meter shown in fig. 1 or integrated into an optical communication device in a manner similar to the OTDR module of fig. 2.

The laser source 10 functions to emit a plurality of probe lights of a predetermined dominant wavelength (or referred to as OTDR wavelength) in a time division manner. In some embodiments, the probe light may be, for example, an optical pulse having a predetermined OTDR wavelength. The predetermined OTDR wavelengths of the plurality of probe lights may be the same or different depending on the type of the optical transmission selecting device 20 to be used later.

In general, it is advantageous that the OTDR wavelength is different from the traffic wavelength, which can avoid interference of the OTDR wavelength with the traffic wavelength. By way of example only, the traffic wavelength may be selected from the range of 1524nm to 1626nm, for example, while the OTDR wavelength may be 1511nm, 1491nm, or 1620nm, for example. In particular, it may be advantageous for the OTDR wavelength to be selected close to the traffic wavelength, as this may help to determine the fibre transmission state during normal traffic communication more accurately.

The optical transmission selection device 20 may be coupled to the laser source 10 and a plurality of optical fibers f1 … … fn, which function to: receives a plurality of probe lights emitted from the laser light source 10 and transmits the plurality of probe lights to a plurality of optical fibers in different directions, so that one optical fiber receives one probe light correspondingly. According to the design of the present disclosure, the number n of the plurality of optical fibers f1 … … fn may be in the range of 2 to 32, and the number of probe lights emitted by the laser source 10 may be the same as the number of the plurality of optical fibers f1 … … fn.

As a typical example of the optical transmission selecting device 20, it may be, for example, 1: n filters or optical switches, n may be equal to the number of the plurality of optical fibers f1 … … fn. Typically, 1: the n-filter may be a comb filter.

In the case of the optical transmission selecting device 20, 1: in the case of an n-filter, the plurality of probe lights emitted by the laser light source 10 may have, for example, OTDR wavelengths, such as λ1, λ2, λn, respectively, which are different from each other. Easily understood, 1: the n filter itself has the property of transmitting light of different wavelengths in different directions, and therefore, the detection light of different wavelengths can be transmitted through 1: the n filters are coupled to different fibers. For example, in this case, the optical fiber f1 may receive the detection light having the wavelength λ1, the optical fiber f2 may receive the detection light having the wavelength λ2, … …, and the optical fiber fn may receive the detection light having the wavelength λn.

In the case where the optical transmission selection device 20 is an optical switch, the OTDR wavelengths of the plurality of probe lights emitted by the laser source 10 may be the same or different, because the optical switch is an active switching element that can manipulate the reflection direction of the probe lights by the optical switch (e.g., a micromechanical mirror MEMS) as needed, so that: even for different probe lights of the same OTDR wavelength, the coupling of the different probe lights to the optical fibers of different directions can be realized.

And 1: the use of an optical switch may alleviate the requirements on the laser source 10 compared to an n-filter. For example, in some embodiments, the laser source 10 may not need to operate in a time division manner, i.e., may continuously output probe light at the same OTDR wavelength. In this way, however, there is a high demand for both the optical switch and the optical receiver, which is that: to achieve the effect of monitoring the quality of the optical fibers in all directions in real time, the optical switch needs to be switched in a rapid cycle in all directions, and a certain time (for example, 50 ms) is allocated to each direction; at the same time, the optical receiver 30 must be completely synchronized with the optical switch, or there is confusion (e.g., when the optical receiver switches later than the optical switch switches, the light received by the receiver is from direction 2 but is mistaken for direction 1, and thus the correct result is not obtained).

In order to make the overall optical fiber quality monitoring apparatus 100 more compact, the optical transmission selection device 20 may optionally be indirectly coupled to the laser source 10 via a transmission/reflection device 40, which transmission/reflection device 40 may transmit a plurality of detection light to the optical transmission selection device 20 on the one hand, and may reflect a plurality of reflected and/or scattered light from a plurality of optical fibers received from the optical transmission selection device 20 to the optical receiver 30 on the other hand. As an example, the transmissive/reflective device 40 may be, for example, an optical circulator; as yet another example, the transmissive/reflective device 40 may be, for example, a polarizing device adapted to transmit probe light configured to have a first polarization direction and reflect a plurality of reflected and/or scattered light having a second polarization direction.

It will be readily appreciated that it is also possible for the light transmission selection device 20 to be directly coupled to the laser source 10 without the transmission/reflection device 40, but such a configuration may add to the complexity of the design of the light transmission selection device 20.

The optical transmission selection device 20 may be directly or indirectly coupled to a plurality of optical fibers f1 … … fn. In embodiments where the optical transmission selection device 20 may be indirectly coupled to a plurality of optical fibers f1 … … fn, this may be the case, for example, where the optical transmission selection device 20 is integrated in an optical communication device, where the optical transmission selection device 20 may be connected to the plurality of optical fibers f1 … … fn via an optical coupling device (which may include a combiner device) in the optical communication device.

The optical receiver 30 is operative to receive and process the plurality of reflected and/or scattered light received from the optical transmission selection device from the plurality of optical fibers based on the principles of OTDR so as to enable monitoring of the quality of each of the plurality of optical fibers. In some embodiments, the optical receiver 30 may be coupled to an optical transmission selection device, for example via a transmission/reflection device 40, to enable the reception and processing of multiple reflected and/or scattered light from the multiple optical fibers. It will be readily appreciated that in certain embodiments, it is also possible that the optical receiver 30 is directly coupled to the optical transmission selection device 20.

For a further understanding of the principles of the present disclosure, the following will be referred to as 1: the n-filter is used as an example of the optical transmission selecting device 20 to describe the transmission timing of the plurality of probe lights emitted by the laser light source 10 and the reception timing of the plurality of reflected and/or scattered lights received by the optical receiver 30.

Fig. 4 shows that the optical fiber quality monitoring device of the present disclosure has a configuration of 1: the transmission timing of the plurality of probe lights emitted in a time-division manner in the case of the n-filter is schematically shown.

As shown in fig. 4, in the case of the optical transmission selecting device 20, 1: in the case of an n-filter, the laser source 10 may transmit n probe lights toward the light transmission selection device 20 in a time-division manner for a first period T1, for example, via the transmission/reflection device 40.

Here, assuming that n=10, there will be 10 probe lights emitted in a time-division manner in the first period T1. For example, the laser source 10 may emit a probe light having a wavelength λ1 at time T1 within the first time period T1, which probe light having a wavelength λ1 will propagate forward into 1: n filters, which then filter out the probe light of wavelength λ1 and couple it into fiber f1; and emitting a probe light with a wavelength of λ2 at time T2 within the first time period T1, the probe light with the wavelength of λ2 will propagate forward into 1: an n-filter, which filters out the probe light with the wavelength λ2 and couples it into the fiber f2; by analogy, a probe light of wavelength λ10 may be emitted at time T10 within the first time period T1, which probe light of wavelength λ10 will propagate forward into 1: n filters which then filter out the probe light of wavelength x 10 and couple it into the fiber f10.

In some embodiments, each probe light may have a predetermined emission duration (which may also be referred to as an emission time slot, while the emission duration is similar to a "pulse duration"), and the emission durations corresponding to the plurality of probe lights are identical to each other. This may facilitate control of the emission of the plurality of probe lights by the laser source. However, it is easily understood that it is also possible that the emission durations of the different probe lights are different from each other. Further, in some embodiments, each transmit duration may be set to be at least equal to or greater than a certain threshold, e.g., 10ms,20ms,50ms, etc.

In some embodiments, in addition to the first period T1 emitting a plurality of detection lights, the laser source 10 may emit a plurality of detection lights in a time-division manner similar to the first period T1, in a second period T2 after the first period T1, in a third period T3 after the second period T2, and so on, or even in an mth period Tm after the mth-1 period Tm-1. That is, a plurality of probe lights emitted in a time-division manner may be repeatedly performed, the number of repetitions being m, where m may be 1 or more. In some embodiments, m may be at least greater than 300, 500, or 600. It will be appreciated that the larger the value of the repetition number m, the more samples of reflected and/or scattered light received from each optical fiber, which facilitates more accurate monitoring of the fiber quality of each optical fiber.

In still other embodiments, the plurality of probe lights emitted in a time division manner may also be repeatedly performed with a predetermined period T. In this case, the first, second, third, and mth periods T1, T2, T3, and Tm may be equal to the predetermined period T, for example. The predetermined period T may also be equal to the emission duration times the number of the plurality of detection lights (or the number of the plurality of optical fibers n), assuming that the corresponding plurality of emission durations of the plurality of detection lights are identical to each other. For example, in the case where n=10, a plurality of transmission durations are identical to each other, and each transmission duration is equal to 50ms, the predetermined period T may be equal to 50ms×10=500 ms, that is, 0.5s.

It is easily understood that in other embodiments, it is also possible that the above-described plurality of detection lights emitted in a time-division manner are not repeatedly performed with a predetermined period (or variably) therebetween. For example, there may be: the time length of the former period Tm-1 may be different from the time length of the latter period Tm, where m is greater than 1.

In response to the transmission of each probe light in a corresponding optical fiber, each optical fiber will accordingly produce a corresponding reflected and/or scattered light. The plurality of probe light will produce a plurality of corresponding reflected and/or scattered light that will travel back along the corresponding optical fiber to the optical transmission selection device 20 and then be received by the optical receiver 30 via the optical transmission selection device 20 (or further via, for example, an optical circulator).

Fig. 5 shows that the optical fiber quality monitoring device of the present disclosure has a configuration of 1: the timing of the reception of the plurality of reflected and/or scattered light received in the case of an n-filter.

With reference to fig. 4 and 5, it is readily understood that the detection light having a wavelength λ1 emitted at time T1 within the first time period T1 will cause the optical receiver 30 to receive reflected and/or scattered light having a wavelength λ1 at time T1 'within the first time period T1'; the detection light having a wavelength of λ2 emitted at time T2 within the first time period T1 will cause the optical receiver 30 to receive reflected and/or scattered light having a wavelength of λ2 at time T2 'within the first time period T1'; by analogy, detection light of wavelength λ10 emitted at time T10 within the first time period T1 will cause the optical receiver 30 to receive reflected and/or scattered light of wavelength λ10 at time T10 'within the first time period T1'.

Similarly, detection light of wavelength λ1 emitted at time T11 within the second time period T2 will cause the optical receiver 30 to receive reflected and/or scattered light of wavelength λ1 at time T11 'within the second time period T2'; the detection light having a wavelength of λ2 emitted at time T12 within the second time period T2 will cause the optical receiver 30 to receive reflected and/or scattered light having a wavelength of λ2 at time T12 'within the second time period T2'; by analogy, detection light of wavelength λ10 emitted at time T10 within the second time period T2 will cause the optical receiver 30 to receive reflected and/or scattered light of wavelength λ10 at time T10 'within the second time period T2'. That is, in the case where a plurality of probe lights emitted in a time-division manner are repeatedly performed m times, the optical receiver 30 may receive m reflected and/or scattered lights for each of the optical fibers f1 … … fn. As previously described, m may be 1 or more. And in some embodiments m is, for example, at least 300, 400, 500, or 600. It will be readily appreciated that receiving more reflected and/or scattered light for each fiber may help to achieve more accurate monitoring of fiber quality.

In the case where the plurality of emission durations corresponding to the plurality of detection lights are identical to each other, the reception duration of each of the plurality of reflected and/or scattered lights is also substantially identical, and may be substantially equal to the emission duration of each detection light. Further, in the case where a plurality of probe lights emitted in a time-division manner are repeatedly performed with a predetermined period T, a plurality of reflected and/or scattered lights will also be received by the optical receiver 30 with a predetermined period T ', wherein the predetermined period T' is substantially equal to the predetermined period T.

Although the above is given by 1: the n-filter describes, as an example of the optical transmission selection device, the reception timings of the plurality of detection lights and the reception timings of the corresponding plurality of reflected and/or scattered lights, but as described above, the optical transmission selection device 20 may also be selected to divide 1: other optical transmission selection devices than n filters, such as optical switches. In embodiments using optical switches, the timing of the reception of the probe light for the plurality of optical fibers and the corresponding timing of the reception of the reflected and/or scattered light may be substantially the same, but with the difference that the wavelength of the probe light for the plurality of different optical fibers may optionally remain the same, at which time the laser source 10 may optionally operate in a time division or not. Note that: although it is possible that the laser source 10 does not realize the continuous output of the probe light of the same OTDR wavelength in a time division manner, it is possible to cause a plurality of probe lights of the same OTDR to be transmitted into corresponding ones of a plurality of optical fibers in different directions, respectively, by the operation of the optical switch, at which time the plurality of probe lights can be regarded as being emitted by the optical switch in a time division manner.

It is easily understood that the above-described optical fiber monitoring apparatus 100 of the present disclosure can realize parallel monitoring of the quality of a plurality of optical fibers f1 … … fn by means of a plurality of probe lights emitted in a time-division manner. Further, it is also understood that since a plurality of probe lights in the optical fiber quality monitoring scheme of the present disclosure can be repeatedly performed at a predetermined period, this means: the optical receiver 30 may evaluate the quality of each optical fiber repeatedly based on the data of the reflected and/or scattered light received during the last predetermined period T at all times, which may be equal to the predetermined period T of the probe light described above. Thus, the quality of each fiber evaluated by the optical receiver 30 may reflect at least the fiber state prior to the last period (e.g., 500 ms=0.5 ms). It is readily understood that in embodiments of the present disclosure, the predetermined period T may be designed to be so short that fiber quality monitoring for each of the plurality of optical fibers may be considered real-time monitoring.

It is also easily understood that the optical fiber quality monitoring structure obtained from the above-described optical receiver 30 may also be transmitted to a network management center, so that parallel and real-time monitoring of the connected plurality of optical fibers can be remotely implemented at the network management center.

It is also readily understood that the fiber optic quality monitoring device of the present disclosure may be presented separately in the form of a meter or integrated into an optical communication device. An example of the application of the optical fiber quality monitoring device of the present disclosure in an optical communication device will be briefly described below with reference to fig. 6.

As shown in fig. 6, the optical fiber quality monitoring device 100 may be integrated in an optical communication device such as a network element a, which may be connected to a network element B via an optical fiber f1, to a network element C via an optical fiber f2, and to a network element D via an optical fiber f3, for example.

To enable parallel and real-time monitoring of the quality of each of the plurality of optical fibers f1, f2, f3, the optical fiber quality monitoring device 100 may be coupled to the optical transmission device D1 via a transition optical fiber 110 disposed in direction 1, to the optical transmission device D2 via a transition optical fiber 120 disposed in direction 2, and to the optical transmission device D3 via a transition optical fiber 130 disposed in direction 3. The probe light having the OTDR wavelength may then propagate in the transition fibers 110, 120, 130 and be combined with the traffic signal having the traffic wavelength in the optical transmission devices D1, D2 and D3, respectively, and then propagate towards the network element B, C, D via the fibers f1, f2, f3, respectively. Accordingly, the plurality of reflected and/or scattered light originating from the optical fibers f1, f2, f3 will be transmitted back into the optical receiver 30 of the optical fiber quality monitoring device 100.

Once any one or more of the optical fibers f1, f2, f3 fail, the optical receiver 30 of the optical fiber quality monitoring device 100 may determine which one or more of the plurality of optical fibers has a problem with the quality based on the detected plurality of reflected and/or scattered light from the plurality of optical fibers, thereby enabling monitoring of the quality of each of the plurality of optical fibers.

It is readily understood that the optical fiber quality monitoring device 100 provided in the optical communication device does not affect the normal traffic of the optical communication device. For example, traffic signals from network element B, C, D can be freely switched to a desired network element direction based on a wavelength selective switch WSS provided within network element a without being affected by the optical fiber quality monitoring device 100.

The flow of a fiber quality monitoring method 700 according to an example embodiment of the present disclosure will be described below with brief reference to fig. 7.

As shown in fig. 7, at block 710, a plurality of probe lights are emitted in a time division manner using the laser source 10.

In some embodiments, the probe light may be, for example, a pulse of light having a predetermined dominant wavelength (or referred to as an OTDR wavelength). The predetermined OTDR wavelengths of the plurality of probe lights may be the same or different depending on the type of optical transmission selection device 20 coupled to the fiber under test.

In general, it is advantageous that the OTDR wavelength is different from the traffic wavelength, which may avoid interference of the OTDR wavelength with the traffic wavelength, but at the same time the OTDR wavelength is also selected as close as possible to the traffic wavelength in order to simulate the communication state of the traffic wavelength in the optical fiber.

In some embodiments, the block 710 may further comprise: a plurality of detection lights are repeatedly emitted in a time-division manner with a predetermined period by the laser light source. As an example, the number m of repetitions in a predetermined period may be, for example, greater than 300, 400, 500, or 600. In this way, it may be helpful for the optical receiver to receive more reflected and/or scattered light, thereby improving the accuracy of monitoring the quality for each fiber.

At block 720, the plurality of probe lights received from the laser source are transmitted to the plurality of optical fibers, respectively, in different directions using the optical transmission selection device such that one optical fiber correspondingly receives one probe light.

The optical transmission selection device 20 may be coupled to the laser source 10 and the plurality of optical fibers f1 … … fn to receive the plurality of probe light emitted from the laser source 10 and transmit the plurality of probe light to the plurality of optical fibers in different directions, and may also be used to receive the plurality of reflected and/or scattered light from the plurality of optical fibers. In some embodiments, the number of the plurality of probe lights may be the same as the number of the plurality of optical fibers. In still other embodiments, the number of the plurality of optical fibers may be in the range of 2 to 32.

As an example of the light transmission selecting device, the light transmission selecting device 20 may be, for example, 1: n filters or optical switches.

In the case of the optical transmission selecting device 20, 1: in the case of an n-filter, the OTDR wavelengths of the plurality of probe lights emitted from the laser source 10 may be designed to be different from each other so as to be 1: the n-filter is capable of filtering out the desired OTDR wavelength from different directions. Whereas in case the optical transmission selection device 20 is an optical switch, it is possible that the OTDR wavelengths of the plurality of probe lights are identical to each other, because the optical switch can be manipulated such that: even a plurality of probe lights of the same wavelength can be reflected to the corresponding optical fibers in different directions.

At block 730, the plurality of reflected and/or scattered light from the plurality of optical fibers received from the optical transmission selection device is processed with an optical receiver to enable monitoring of the quality of each of the plurality of optical fibers.

The optical receiver 30 may receive and process the received plurality of reflected and/or scattered light based on the principles of OTDR. It will be readily appreciated that each of the plurality of reflected and/or scattered light may reflect the link quality of the corresponding optical fiber to which the optical fiber quality monitoring device is coupled. Thus, monitoring the quality of each of the plurality of optical fibers may be achieved by processing the received plurality of reflected and/or scattered light.

In some embodiments, the block 730 may further include: monitoring of the quality of each optical fiber is achieved based on processing at least 300 reflected and/or scattered light received from the optical transmission selection device for each optical fiber. It will be readily appreciated that a more accurate monitoring of the quality of the optical fiber may be achieved based on the processing of more reflected and/or scattered light.

In addition to the steps of blocks 710 through 730 described above, the method 700 may further include: a transmission/reflection device 40, such as an optical circulator, is used to transmit the plurality of probe light to the optical transmission selection device and to reflect the plurality of reflected and/or scattered light to the optical receiver. It will be readily appreciated that this may be achieved by providing a transmission/reflection device 40, such as an optical circulator, between the optical transmission selection device 20 and the laser source 10. It is also readily appreciated that in this manner, the overall structure of the fiber quality monitoring device 100 may be made more compact.

The flow of the method of optical fiber quality monitoring according to the present disclosure has been described above. It is readily understood that the method of optical fiber quality monitoring of the present disclosure may achieve all of the respective advantages of the optical fiber quality detection apparatus of the present disclosure described above. Furthermore, all relevant features of the embodiments described above in relation to the optical fiber quality detection apparatus may be adapted for use in embodiments of the method of optical fiber quality monitoring.

It is also to be readily understood that the above-described methods and apparatus are merely examples. Although the steps of a method are described in a particular order, this does not require or imply that the operations be performed in the particular order, or that all of the illustrated operations be performed in order to achieve desirable results, and that the order in which the steps are performed may be altered. Additionally or alternatively, certain steps may be omitted, multiple steps combined into one step to perform, and/or one step decomposed into multiple steps to perform.

While the invention has been illustrated and described in detail in the drawings and foregoing description, such illustration and description are to be considered illustrative or exemplary and not restrictive; the invention is not limited to the disclosed embodiments. Other variations to the disclosed embodiments can be understood and effected by those skilled in the art in practicing the claimed invention, from a study of the drawings, the disclosure, and the appended claims.

In the claims, the word "comprising" does not exclude other elements, and the indefinite article "a" or "an" does not exclude a plurality. A single element or other unit may fulfill the functions of several items recited in the claims. The mere fact that certain features are recited in mutually different embodiments or in dependent claims does not indicate that a combination of these features cannot be used to advantage. The scope of the present application encompasses any possible combination of the features recited in the various embodiments or the dependent claims without departing from the spirit and scope of the present application.

Furthermore, any reference signs in the claims shall not be construed as limiting the scope of the invention.

Claims

1. A fiber quality monitoring device, comprising:

a laser light source configured to emit a plurality of probe lights in a time-division manner;

an optical transmission selection device coupled to the laser source and the plurality of optical fibers and configured to transmit the plurality of probe lights received from the laser source to the plurality of optical fibers in different directions, respectively, such that one optical fiber correspondingly receives one probe light; and

an optical receiver coupled to the optical transmission selection device and configured to process a plurality of reflected and/or scattered light from the plurality of optical fibers received from the optical transmission selection device so as to enable monitoring of the quality of each of the plurality of optical fibers.

2. The optical fiber quality monitoring device of claim 1, wherein the laser source is further configured to repeatedly emit the plurality of probe lights in the time-division manner at a predetermined period.

3. The optical fiber quality monitoring apparatus according to claim 2, wherein each of the probe lights has an emission duration, and a plurality of emission durations corresponding to the plurality of probe lights are identical to each other.

4. A fiber quality monitoring apparatus according to claim 3, wherein the predetermined period is equal to the emission duration times the number of the plurality of probe lights.

5. The fiber optic quality monitoring device of any of claims 3-4, wherein the transmission duration is at least 10ms.

6. The optical fiber quality monitoring device according to any one of claims 1-4, wherein the number of the plurality of probe lights is the same as the number of the plurality of optical fibers, and the number of the plurality of optical fibers is in a range of 2 to 32.

7. The fiber quality monitoring device of any of claims 1-4, the optical receiver further configured to: monitoring of the quality of each optical fiber is achieved based on processing at least 300 reflected and/or scattered light received from the optical transmission selection device for each optical fiber.

8. The optical fiber quality monitoring device of any of claims 1-4, further comprising an optical circulator disposed between the laser source and the optical transmission selection device and further configured to: transmitting the plurality of detection light to the light transmission selection device, and reflecting the plurality of reflected and/or scattered light to the light receiver.

9. The optical fiber quality monitoring apparatus according to any one of claims 1 to 4, wherein dominant wavelengths of any two of the plurality of probe lights are different from each other, and the light transmission selecting device is 1: an n-filter or an optical switch, where n is equal to the number of the plurality of optical fibers.

10. The optical fiber quality monitoring device of any of claims 1-4, wherein dominant wavelengths in the plurality of probe lights are the same, and the optical transmission selection means is an optical switch.

11. A method for monitoring the quality of optical fiber includes such steps as,

emitting a plurality of probe lights in a time division manner using a laser source;

transmitting the plurality of detection lights received from the laser source to a plurality of optical fibers in different directions, respectively, using a light transmission selection device, such that one optical fiber correspondingly receives one detection light; and

the plurality of reflected and/or scattered light from the plurality of optical fibers received from the optical transmission selection device is processed with an optical receiver to enable monitoring of the quality of each of the plurality of optical fibers.

12. The optical fiber quality monitoring method of claim 11, wherein emitting a plurality of probe lights in a time-division manner using a laser light source comprises:

the plurality of detection lights are repeatedly emitted in the time-division manner with a predetermined period by the laser light source.

13. The optical fiber quality monitoring method of claim 11, wherein processing the plurality of reflected and/or scattered light from the plurality of optical fibers received from the optical transmission selection device with an optical receiver comprises:

14. The optical fiber quality monitoring method according to any one of claims 11 to 13, wherein dominant wavelengths of any two of the plurality of probe lights are different from each other, and the light transmission selecting device is 1: an n-filter or an optical switch, where n is equal to the number of the plurality of optical fibers.

15. The optical fiber quality monitoring method according to any one of claims 11 to 13, wherein dominant wavelengths in the plurality of probe lights are the same, and the optical transmission selecting device is an optical switch.

16. The optical fiber quality monitoring method according to any one of claims 11-13, using an optical circulator to transmit the plurality of probe light to the optical transmission selection device, and to reflect the plurality of reflected and/or scattered light to the optical receiver.

17. An optical communication device for an optical fiber, comprising the optical fiber quality monitoring device according to any one of claims 1-10.