JP2009276627A - Communication light detector - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a communication light detector by which existence/nonexistence of using state of optical transmission lines is visibly and easily determined by using invisible light propagating in the optical transmission lines. <P>SOLUTION: The communication light detector 1, by which end parts of the optical transmission lines composed of optical fibers 2a and 2b are connected via a sleeve 6, and the existence/nonexistence of the communication light in the optical transmission lines is detected at the connection part, comprises: an optical detection connector 7 which is provided at the connection part in the sleeve 6, connects the end parts of the optical transmission lines, and has a core part 9 of which the outer diameter is different from that of the core 3 of the optical transmission lines; and an optical detection part which is provided above the optical detection connector 7 and detects the leaked light of the communication light leaked via the optical detection connector 7. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a communication light detector that is installed in an optical transmission line and confirms the communication status of the optical transmission line.

  In recent years, in the field of communication, optical fibers capable of high-speed and large-capacity transmission have become mainstream transmission lines, and further development is expected. As a result, especially in optical communication related facilities such as data centers and office buildings, construction, such as changing, abolishing, or adding optical transmission paths, has been frequently performed.

  Since the communication light transmitted through the optical transmission line of such an optical communication-related facility is invisible light not in the visible light region, it cannot be visually confirmed. For this reason, it is not possible to easily grasp the operational status such as whether or not the optical transmission line is used, and it takes time to grasp the operational state, or the optical connector of the used optical transmission line is not used. There are concerns such as human error that can be mistaken for a human error, and there is a problem that an unused optical transmission line in an optical communication-related facility cannot be used effectively.

  Therefore, in order to improve the maintainability and operational efficiency of the optical communication related equipment, many means for visually confirming the optical transmission path are being studied.

  As a communication light detector for confirming the presence or absence of communication light with an optical fiber connected, for example, a gap is provided between the end faces of ferrules in which the optical fiber is built and butt-connected in the split sleeve, A waveguide made of a light-transmitting resin is provided, and a part of communication light guided above the waveguide is received by a phosphor to detect the presence or absence of transmission of communication light (for example, Patent Document 1). reference).

  Also, a method of confirming the presence or absence of communication light by disposing an optical waveguide substrate between two ferrules incorporating an optical fiber, branching out part of the communication light at the optical waveguide substrate, and taking it out to the communication light output unit Has been proposed (see, for example, Patent Document 2).

  A communication light detector having a structure in which a visible light conversion element is attached to a terminal portion of the branched light using a branching device that branches and extracts a part of the communication light has been studied (for example, see Patent Document 3).

JP 2004-170488 A JP 2004-133071 A JP 2003-218813 A JP 2002-214487 A

  However, in the communication light detector of Patent Document 1, since a waveguide is provided in a very narrow gap, time and high-level alignment are necessary for the assembly. Moreover, since the light detector is made of a phosphor, its light emission time is extremely short and difficult to visually check, making it difficult to use in optical communication related equipment.

  Further, in Patent Document 2, since it is necessary to connect the optical waveguide substrate to the ferrule and the communication light output unit, the time and high-precision alignment are necessary for the assembly, and the optical waveguide substrate, etc. Since the member is expensive, it has been difficult to realize cost reduction for further practical use.

  Even in Patent Document 3, the light emission time of the visible light conversion element is extremely short and difficult to visually confirm.

  Accordingly, an object of the present invention is to provide a communication light detector that can easily visually determine whether or not an optical transmission line is in use by using invisible light propagating through the optical transmission line.

  Another object of the present invention is to improve a decrease in detection sensitivity depending on the position of a light receiving element in a communication light detector.

  The present invention, which was created to achieve the above object, connects the end portions of an optical transmission line made of an optical fiber via a sleeve, and detects the presence or absence of communication light in the optical transmission line at the connection part. In the optical detector, provided at the connection portion in the sleeve, and is bonded to the ends of the optical transmission path, and has a core portion having an outer diameter different from the core of the optical transmission path, and It is a communication light detector provided with the light detection part which is provided above the said light detection coupling body, and detects the leakage light of the communication light which leaks through the said light detection coupling body.

  The optical detection joined body may have an axial length equal to a distance from a core of the optical transmission path to a light receiving surface of the light detection unit that receives the leakage light.

  The optical detection joined body may further include a clad portion that is provided around the core portion and has the same outer diameter as the clad of the optical transmission line.

  The light detection joined body may include a ferrule.

  The light detection unit may include a light receiving element that receives the leaked light and a light output unit that converts the leaked light received by the light receiving element into visible light.

  The light detection unit may further include a failure detection unit that notifies the presence or absence of the failure.

  The sleeve may be made of ceramics that transmits a part of leaked light of communication light leaking through the light detection joined body.

  According to the present invention, it is possible to easily determine visually whether or not the optical transmission path is used by using invisible light propagating through the optical transmission path without depending on the light emission time, and maintainability of the optical transmission path or Operational efficiency can be improved.

  Preferred embodiments of the present invention will be described below with reference to the accompanying drawings.

  First, the overall configuration of the communication light detector will be described with reference to FIGS. 1 (a) and 1 (b).

  As shown in FIGS. 1 (a) and 1 (b), the communication light detector 1 is provided in a rectangular cylindrical housing 16 in which the main part is accommodated, and a central part on the housing 16, It is an optical adapter type communication light detector provided with a box-shaped cover 17 that covers the detector 12.

  One end (left side in FIG. 2) of the housing 16 is a facility-side optical connector adapter 18c, and the other end (right side in FIG. 1) is a user-side optical connector adapter 18y. In the optical connector adapter 18c on the equipment side, a connector lock piece 19c for inserting and fixing the optical connector plug on the equipment side in advance is provided. Similarly, in the optical connector adapter 18y on the user side, a connector lock piece 19y for fixing the optical connector plug on the user side that is detachably provided is provided.

  A sleeve holder accommodating chamber 21c for accommodating the equipment side sleeve holder 20c is formed behind the connector lock piece 19c in the equipment side optical connector adapter 18c, and the equipment side sleeve holder 20c is accommodated in the sleeve holder accommodating chamber 21c. Is accommodated in advance. Similarly, a sleeve holder accommodating chamber 21y for accommodating a user side sleeve holder 20y is formed on the inner side of the connector lock piece 19y in the optical connector adapter 18y on the user side. The sleeve holder 20y is accommodated in advance.

  In the central portion of the housing 16, a main body housing chamber 22 for housing a detector main body 1 b composed of one sleeve 6 and a light detection joined body 7 is formed. In the main body housing chamber 22, the detector main body 1 b is provided. Pre-contained. A PD accommodating chamber 19 for accommodating the PD 14 is formed in the upper portion of the main body accommodating chamber 22 in the housing 16.

  Engaging portions 24 are formed on both side surfaces of the housing 16 for previously accommodating and fixing the communication light detector 1 in an optical module installed in the optical communication-related facility. Cover lock pieces 25 that stand from the upper surface of the housing 16 and fix the cover 17 on the housing 16 are respectively provided at the four corners of the central portion on the housing 16.

  On both side surfaces of the cover 17, cover lock holes 26 are formed for fitting with the respective cover lock pieces 25. A circuit board 27 is accommodated in the cover 17. The cover 17 is made of a material that is substantially transparent to light emitted from a communication presence / absence determination LED and a circuit failure detection LED, which will be described later.

  On the other hand, the light detection unit 12 converts the PD element 13 (see FIG. 2A described later) and the leakage light E (see FIG. 2C described later) received by the PD element 13 into visible light. A light output unit 28, a failure detection unit 29 that informs whether or not the circuit board 27 has failed, and a circuit board 27 that includes the PD element 13, the light output unit 28, and the failure detection unit 29 and constitutes a light detection circuit. Prepare.

  Further, in the present embodiment, an LED that emits red light is used as the communication presence / absence determination LED, and an LED that emits blue light is used as the circuit failure detection LED. This makes it easy to distinguish between the presence / absence of communication and the detection of circuit failure by visually observing the color of the emitted light, and the communication light detector 1 can be made more reliable.

  In the present embodiment, a communication presence / absence determination LED (light emitting diode) that is turned on when communication light propagates between the optical fibers 2a and 2b and turned off when not propagated is used as the light output unit 28. As the failure detection unit 29, a circuit failure detection LED that is turned on when the circuit board 27 is broken or not operating (for example, when power is not supplied) and turned off when there is no failure is used.

  For example, when only the circuit failure detection LED shines blue (when only blue shines), it indicates that the communication light detector 1 is not operating and is not communicating, and the communication presence / absence determination LED is red. When it shines (when only red light shines), it indicates that the communication light detector 1 is operating and communicating. That is, it is possible to more easily distinguish between the failure of the communication light detector 1 and the presence or absence of communication using LEDs of different colors.

  FIG. 2A is a longitudinal sectional view of the main part of the communication light detector showing the preferred first embodiment of the present invention.

  As shown in FIG. 2A, the communication light detector 1 according to the first embodiment is installed and used in, for example, an optical communication-related facility such as a data center or a station building, and is used as an optical transmission path. In the optical fiber connection part in which the fiber ends are connected to each other, the use state of the optical transmission line is monitored to detect the presence or absence of communication light (whether optical communication is being performed).

  The communication light detector 1 includes an end of ferrules 5a and 5b each containing optical fibers 2a and 2b as optical transmission paths, and a sleeve 6 for aligning the optical axes of the ferrules 5a and 5b. The optical fiber 2a, 2b is provided in the sleeve 6 and joined to the ends of the optical fibers 2a, 2b (ends on the optical fiber connecting portion side) and has an outer diameter (core diameter different from the core 3 of the optical fibers 2a, 2b). The detector main body 1b which consists of the optical detection joining body 7 which has the core part 9 is provided.

  Each optical fiber 2 a, 2 b as an optical transmission line inserted into the communication light detector 1 includes a core 3 and a clad 4. As these optical fibers 2a and 2b, a single mode optical fiber made of quartz glass or a GI (graded index) type multimode optical fiber is generally used. When single mode optical fibers are used as the optical fibers 2a and 2b, communication light having a wavelength of 1310 nm band or 1550 nm band is used. When a multimode optical fiber is used as each optical fiber, communication light having a wavelength of 850 nm band or 1310 nm band is used.

  The ferrule 5a is built in the optical connector plug 33c on the facility side (see FIG. 3A described later), and the ferrule 5b is built in the optical connector plug 33y on the user side (see FIG. 3A described later). . These ferrules 5a and 5b are made of ceramics or metal, and are polished so that their end faces (end faces on the optical fiber connecting portion side) become PC (physical contact) end faces.

  The sleeve 6 is made of ceramic or glass that transmits at least a part of communication light (or scatters when receiving communication light), or made of ceramic or glass having a slit extending in the sleeve longitudinal direction (axial direction). Use a metal or metal split sleeve. Examples of the ceramic that transmits at least a part of the communication light include zirconia ceramics.

  The optical detection joined body 7 is provided around the core portion 9 which is joined to the center of the end portion of the core 3 of the optical fibers 2a and 2b, and around the core portion 9, and is the same as the cladding 4 of the optical fibers 2a and 2b. It consists of a clad part 10 having a diameter and a ferrule part 11 provided around the clad part 10. In the light detection joined body 7, a portion including the core portion 9 and the clad portion 10 serves as a light transmission path 8 on the detection side.

  In the optical detection joined body 7, the core part 5 is made of the same material as the core 3 of each optical fiber 2a, 2b, and the clad part 10 is made of the same material as the clad 4 of each optical fiber 2a, 2b. Since both end faces of the optical detection joined body 7 in the longitudinal direction of the optical fiber are PC-connected to end faces of the optical fibers 2a and 2b (end faces on the optical fiber connecting portion side), they are polished so as to become PC end faces. The outer diameter of the optical detection joined body 7 (the outer diameter of the ferrule portion 11) is the same as or smaller than the outer diameter Φf of each of the ferrules 5a and 5b.

  When the light incident direction is a white arrow, the joint between the light detection joined body 7 and the optical fiber 2a becomes a loss occurrence place due to a difference in core diameter, as shown in FIG. The same applies when the light incident direction is a black arrow. For this reason, the transmission loss when the communication light C passes through the joint J between the optical detection joined body 7 and the optical fiber 2a and a part thereof leaks as the leaked light E is in a range that does not adversely affect the optical communication. The core diameter of the core portion 9 of the light detection joined body 7 is set so as to be 1 to 2 dB. The core portion 9 of the light detection joined body 7 can be manufactured with a core diameter of about 2 to 3 μm.

  In the present embodiment, an example in which the core diameter of the core portion 9 of the light detection bonded body 7 is smaller than the core diameter of the core 3 of the optical fibers 2a and 2b will be described. Even when the core diameter is larger than the core diameter of the core 3 of the optical fibers 2a and 2b, the same action as in FIG. Also in this case, the outer diameter of the clad part of the optical detection joined body 7 and the outer diameter of the clad 4 of the optical fibers 2a and 2b are the same.

  Returning to FIG. 2A, the communication light detector 1 includes a light detection unit 12 that is provided above the light detection bonded body 7 and detects leakage light E that leaks through the light detection bonded body 7. Specifically, the light detection unit 12 is arranged at a symmetrical position with respect to the light detection bonded body 7 and the sleeve 6 so that the light receiving surface that receives the leakage light E is parallel to the light transmission path. In FIG. 2A, only the PD 14 that constitutes a part of the light detection unit 12 and includes the PD element 13 as a light receiving element that receives the leakage light E is illustrated. In this embodiment, an inexpensive can package type PD 14 is used.

  The optical detection joined body 7 may have an axial length L equal to the distance Q from the core 3 of each of the optical fibers 2 a and 2 b to the light receiving surface of the PD element 13. In this case, since about 50% of the leaked light E is incident on the PD 14, the detection sensitivity of the leaked light is maximized.

  That is, in each of the ferrules 5a and 5b having the diameter Φf, since the distance from the light incident port 15 of the PD 14 to the light receiving surface of the PD element 13 is Lr and the ferrule radius is Φf / 2, if the thickness of the sleeve 6 is d, the loss The distance Q from the generation point to the light receiving surface of the PD element 13 is Q = Lr + (Φf / 2) + d. At this time, if the length L is equal to the distance Q (the length L and the distance Q are approximately 2.35 mm + d because Φf = 2.5 mm in a general ferrule), the detection sensitivity of the leaked light E is optimal. Become.

  Next, an example of an optical module using the communication light detector 1 will be described with reference to FIGS. 3 (a) and 3 (b).

  As shown in FIGS. 3A and 3B, the optical module (optical pre-wiring module) 31 includes a plurality of communication light detectors 1 in the case 32 (four in FIG. 3A). Contained mainly composed. Examples of the optical module 31 include a light aggregator and an optical termination box installed in an optical communication-related facility, and an aerial light closure.

  The case 32 includes a box-shaped lower case (fiber storage tray) 32d and a lid 32u provided on the lower case 32d so as to be freely opened and closed. In this embodiment, the lid 32u is made of a material that is substantially transparent to the light emitted from the communication presence / absence determination LED and the circuit failure detection LED.

  At the end of the lower case 32d, the optical connector adapter 18y on the user side of each communication light detector 1 is accommodated and fixed so as to protrude in the longitudinal direction of the lower case 32d. Each user-side optical connector adapter 18y is provided with a user-side optical connector plug 33y, in which the optical fiber 2b and the ferrule 5b (see FIG. 2A) are built, so that they can be inserted and removed. In the present embodiment, an SC optical connector is used as an example of an optical connector composed of the user-side optical connector adapter 18y and the user-side optical connector plug 33y.

  In the optical connector plug 18c on the equipment side of each communication light detector 1, an optical connector plug 33c on the equipment side containing the optical fiber 2a and the ferrule 5a (see FIG. 2A) is inserted and fixed in advance. Is done.

  When using an optical transmission line, a user-side optical connector plug 33y is inserted into and fixed to the user-side optical connector adapter 18y corresponding to the optical transmission line to be used. The fiber and the optical fiber 2a as an optical transmission line on the facility side are optically coupled.

  In the lower case 32d, there is provided a fiber surplus length storage portion 34 for storing the surplus length of the optical fiber 2a extending from the equipment-side optical connector plug 18c. A plurality of optical fibers 2a are bundled via a fiber extra-length storage section 34 and connected to the outside of the optical module 31 as an optical fiber cable.

  In the lower case 32d, a power supply unit 35 that supplies power to the light detection unit 12 is provided between each communication light detector 1 and the extra fiber length storage unit 34. The power supply unit 35 and the circuit board 27 of each communication light detector 1 are connected by a power feeding cable 36, respectively. As the power supply unit 35, a battery or a solar panel is used.

  The operation of the first embodiment will be described.

  It is assumed that the user-side optical connector plug 33y is inserted and fixed to the user-side optical connector adapter 14y corresponding to the optical transmission path to be used, and communication is performed from the equipment side toward the user side.

  In this case, as shown in FIGS. 2 (a) and 2 (c), the communication light C passes through the optical fiber 2a in the ferrule 5a built in the optical connector on the equipment side, and the optical fiber 2a and the optical detection junction. The joint J of the body 7 is reached.

  When the communication light C passes through the joint portion J, the core diameter of the core portion 9 of the optical detection joined body 7 is smaller or larger than the core diameter of the core of the optical fiber 2a. The leakage light E spreads from the core end surface of the optical fiber 2a.

  The spread leaked light E passes through the slit of the sleeve 6 or a part thereof passes through the sleeve 6 and is received by the PD element 13 of the light detection unit 12 to be converted into an electric signal. 27 is converted into visible light by the light output unit 28 of the light detection unit 12 and emitted. The same applies to communication from the user side toward the equipment side.

  By visually checking the presence or absence of visible light, for example, it is possible to easily confirm which optical transmission line is used in the optical module 31 of FIG.

  As described above, the communication light detector 1 includes the light detection joined body 7 having the core portion 9 having a core diameter different from that of the core 3 of the optical fibers 2a and 2b as the optical transmission path in the sleeve 6. If only the core diameter of the part 5 is set, a desired amount of leakage light E can be easily extracted from the communication light C.

  In addition, the optical detection joined body 7 has substantially the same configuration and material as the core and clad of the optical fiber, and is the same as the outer diameter of the ferrules 5a and 5b in which the optical fibers 2a and 2b are incorporated as optical transmission paths, Since it has an outer diameter smaller than that, it can be easily manufactured at low cost, and the connection with the optical fibers 2a and 2b and the ferrules 5a and 5b is also simple.

  Therefore, according to the communication light detector 1, it is possible to easily determine visually whether or not the optical transmission path is in use without depending on the light emission time by using invisible light propagating through the optical transmission path. Road maintainability and operational efficiency can be improved.

  Further, since the communication light detector 1 is provided with the light detection unit 8 above the light detection bonded body 7, it is less expensive than the case where the light receiving element is built in the optical connector, and the configuration of the detector itself is also provided. Easy to do.

  Here, the present inventors confirm whether or not the other object of the present invention for improving the decrease in detection sensitivity depending on the position of the light receiving element (for example, PD) is achieved in the communication light detector. Therefore, a communication light detector 41 shown in FIG. 4A was produced as a comparative example of the communication light detector 1, and the leakage light detection sensitivity was examined.

  The communication light detection 41 of the comparative example is filled with the refractive index matching agent m so that the gap g4 is provided between the ferrules 5a and 5b in each optical connector in the optical transmission line, and the leakage light of the communication light generated by the gap g4 Is detected by the PD element 13 of the PD 14 to detect the presence or absence of communication light.

  However, in the communication light detectors 1 and 41, the length L6 of the sleeve 6 is 11.4 mm, the outer diameter Φf of the ferrules 5a and 5b is 2.5 mm, and the light receiving surface of the PD element 13 from the light incident port 15 of the PD14. The distance Lr was 1.1 mm. The reference point for the leakage light detection sensitivity was the light entrance 15 (● in FIG. 2A and FIG. 4A).

  As shown in FIGS. 4B to 4D, in the communication light detector 41, the leakage light detection sensitivity does not change in the light incident direction in the X axis direction and the Z axis direction, but the Y axis direction ( With respect to the longitudinal direction of the optical fiber, the position of the maximum detection sensitivity changes greatly depending on the light incident direction.

  On the other hand, the communication light detector 1 differs in the loss occurrence location depending on the light incident direction between the ferrules 5a and 5b depending on the light detection joined body 7 (there are two places where leakage light E is generated). It has a structure.

  For this reason, the leak detection sensitivity in the Y-axis direction of the communication light detector 1 is not dependent on the light incident direction as shown in FIG. The leakage light detection sensitivity can be improved by about 1.3 times.

  Moreover, according to the communication light detector 1 of FIG. 1, only by providing the light detection joined body 7 provided with the core part 9 which has an outer diameter different from the core of an optical transmission line, the conventional communication light detector of FIG. Such an optical waveguide substrate or the like is unnecessary, and high-precision alignment is unnecessary.

  Furthermore, since the optical detection joined body 7 plays the same role as the conventional ferrule, the number of parts can be reduced as compared with the conventional communication light detector.

  In addition to the configuration of the communication light detector 1 in FIG. 1, like the communication light detector 51 according to the second embodiment shown in FIG. 5, in order to notify the presence or absence of a failure of the PD element 13 or the light output unit 28. A failure detector 52 for the optical element may be provided. As the optical element failure detection unit 52, an optical element failure detection LED that is turned ON / OFF by a switch may be used.

  In this case, a space S5 defined by the side surface of the PD 14, the back surface of the circuit board 27, and the sleeve 6 is formed on one side of the PD accommodating chamber 23 of the housing 16, and the circuit board positioned above the space S5. 27 is mounted on the back surface of the optical element.

  In the communication light detector 51, when the operator turns on the switch, the failure detection light is emitted from the failure detection unit 52 for the optical element toward the sleeve 6, and the failure detection light is reflected (or scattered) by the sleeve 6. ) Is incident on the PD element 13.

  When the PD element 13 and the light output unit 28 are not broken down, it can be seen that the optical element is not broken by an operator viewing the visible light emitted from the light output unit 28. Further, when the PD element 13 and the light output unit 28 are out of order, no visible light is emitted from the light output unit 28 even when the operator turns on the switch. .

FIG. 1A is an external perspective view of a communication light detector showing a preferred first embodiment of the present invention, and FIG. 1B is a longitudinal sectional perspective view thereof. 2A is a longitudinal sectional view of the main part of the communication light detector shown in FIG. 1, FIG. 2B is a view showing the position of the leakage light detection sensitivity in the Y-axis direction, and FIG. It is an enlarged view of a connection part. FIG. 3A is a perspective view showing the internal configuration of the optical module using the communication light detector shown in FIG. 1, and FIG. 3B is a perspective view showing the internal configuration of the light detection unit. 4A is a longitudinal sectional view of a communication light detector of a comparative example, FIG. 4B is a diagram showing the position of the leakage light detection sensitivity in the Y-axis direction, and FIG. 4C is X of the leakage light detection sensitivity. The figure which shows an axial direction position, FIG.4 (d) is a figure which shows the Z-axis direction position of the leak light detection sensitivity. It is a longitudinal cross-sectional perspective view of the communication light detector which shows the 2nd Embodiment of this invention.

Explanation of symbols

1 Communication light detector 2a, 2b Optical fiber (optical transmission line)
3 Core 6 Sleeve 7 Optical detection assembly 9 Core part

Claims (7)

  In a communication light detector for connecting the ends of optical transmission lines made of optical fibers through a sleeve and detecting the presence or absence of communication light in the optical transmission line at the connection part, provided at the connection part in the sleeve A light detection joined body having an outer diameter core portion different from a core of the light transmission path and joined to ends of the light transmission path, and provided above the light detection joined body. A communication light detector, comprising: a light detection unit that detects leakage light of communication light leaking through the joined body.   The communication light detection according to claim 1, wherein the optical detection joined body has an axial length equal to a distance from a core of the optical transmission path to a light receiving surface of the light detection unit that receives the leakage light. vessel.   The communication light detector according to claim 1, wherein the light detection joined body further includes a clad portion that is provided around the core portion and has the same outer diameter as the clad of the optical transmission line.   The communication light detector according to claim 1, wherein the light detection joined body includes a ferrule.   The communication light according to claim 1, wherein the light detection unit includes a light receiving element that receives the leaked light and a light output unit that converts the leaked light received by the light receiving element into visible light. Detector.   The communication light detector according to any one of claims 1 to 5, wherein the light detection unit further includes a failure detection unit that notifies the presence or absence of the failure.   The communication light detector according to claim 1, wherein the sleeve is made of ceramic that transmits a part of leakage light of communication light leaking through the light detection bonded body.

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