JP2003332998A - Optical signal monitoring apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an optical signal monitoring apparatus which is inserted between an existing optical terminal board and a connector of an optical fiber to measure directions and strengths of optical signals accurately and reliably. <P>SOLUTION: The optical signal monitoring apparatus includes an optical signal detector 20 and an optical signal display device 40 connected to the detector 20 via a connection cable 60. The detector 20 is so formed that connectors 21, 22 to be inserted between the optical fiber 1 and the optical terminal board 2 as adapters and a terminal 23 for outputting a detection signal and others are integrally incorporated into a housing 24. A branching film for branching an optical signal and detecting it and a photodiode are arranged inside of the housing 24. The device 40 has switches 41-44 for setting conditions of a test and measurement, an A/D converter for converting a detection signal provided from the detector 20 into a digital signal, LEDs 45-48 for indicating the presence or absence of the optical signal or its propagation direction, and a indicator 49 for displaying a signal level in digital form. <P>COPYRIGHT: (C)2004,JPO

Description

Detailed Description of the Invention

[0001]

TECHNICAL FIELD OF THE INVENTION

The present invention relates to an optical signal monitoring device for inserting an optical fiber or the like into an optical transmission line to monitor an optical signal transmitted through the optical transmission line.

[0003]

[Prior art]

Along with the rapid increase in facilities related to optical communication, constructions such as new additions, expansions, and wiring changes of optical transmission lines are frequently performed. In such construction, inevitably, a lot of work is required to modify the existing optical transmission line. Therefore, it is necessary to provide a means for easily grasping the operational status such as whether or not an optical signal is flowing in the optical transmission line.

Such means is not limited to construction, but also in the operation and maintenance of a huge number of optical transmission lines, the operating conditions can be automatically monitored, and maintenance personnel can monitor the operating states of individual optical transmission lines on site. It is also necessary to confirm with. Also, in the field confirmation work, not only experienced maintenance personnel but also inexperienced maintenance personnel can easily grasp the operation status without fear of accidents such as accidental disconnection of the line. It is desired to have a high monitoring device.

Conventionally, as a technique in such a field, for example, there is one described in Japanese Patent Laid-Open No. 2000-284152.

FIGS. 2A and 2B are block diagrams of the conventional photodetector disclosed in the above publication.

As shown in FIG. 2 (a), the photodetector 10 has an integral structure housed in a light-shielding housing 11, and the optical fiber 1a is provided on both end surfaces of the housing 11. , 1b are formed with connection parts 11a, 11b for connecting the optical connectors 2a, 2b.
LEDs (light emitting diodes) 12a, 1 for displaying the state of the optical signal in the optical transmission line are provided on the side surface of the photodetector 10.
2b and terminals 13a, 13 for power supply and detection signal output
b is provided.

Inside the housing 11, a linear through hole 11c is provided between the connecting portions 11a and 11b, as shown in the cross section of FIG. 2 (b). Further, a through hole 11d which is orthogonal to the through hole 11c is provided at the center of the through hole 11c.

A cylindrical sleeve 14 made of metal is housed inside the through hole 11c. Windows 14a and 14b for guiding a part of the optical signal to the through hole 11d are provided at the center of the sleeve 14. Inside the sleeve 14, an optical fiber 16a protected by ferrules 15a and an optical fiber 16b protected by ferrules 15b are inserted from both ends thereof.

The tips of the optical fibers 16a and 16b are polished at exactly 45 ° together with the ferrules 15a and 15b,
In the windows 14a and 14b at the center of the sleeve 14, surface contact is made with the branching film 17 interposed therebetween. The branching film 17 allows most of the optical signal to pass therethrough and reflects a part of the optical signal. The reflected optical signal is reflected by the window portion 1 of the sleeve 14.
It is adapted to be output to the through hole 11d of the housing 11 from 4a and 14b.

A circuit board 18a, on the surface of which the LEDs 12a, terminals 13a, determination circuits, etc. are mounted, is fixed to one side surface of the housing 11. On the back surface of the circuit board 18a, a PD (photodiode) 19a is mounted so as to fit exactly in the through hole 11d of the housing 11. Similarly, on the other side surface of the housing 11, the LED
The circuit board 18b on which the 12b, the terminal 13b, the PD 19b, the determination circuit, and the like are mounted is fixed.

In the photodetector 10 as described above, most of the optical signal incident from the optical fiber 1a is branched film 1.
7 is transmitted to the optical fiber 1b, is partially reflected by the branch film 17, passes through the window 14a provided in the ferrule 15a and the sleeve 14, and is incident on the PD 19a. The optical signal incident on the PD 19a is converted into a voltage corresponding to the intensity of the optical signal, output to the terminal 13a, and the presence or absence of the optical signal is detected by the determination circuit on the circuit board 18a. When it is determined that the optical signal exists, the determination circuit turns on the LED 12a.

Further, from the optical fiber 1b to the optical fiber 1a
Similarly, the optical signal transmitted in the direction of
It is detected by the PD 19b on the side.

[0015]

However, the conventional photodetector has the following problems.

For example, a part of the optical signal reflected by the branch film 17 may enter the regular PD 19a and be reflected inside the housing 11 and spill into the PD 19b on the opposite side. In such a case, the output signals of the PDs 19a and 19b detect the presence / absence of an optical signal in their respective determination circuits. Therefore, if the circulated optical signal is strong, the light detected by the PD 19b is also determined to be a normal optical signal. , There was a possibility of lack of accuracy.

The PD 19 for detecting the optical signal
Since a, 19b, etc., the determination circuit for displaying the detection result, and the LEDs 12a, 12b, etc. are integrated, the housing 11 inevitably has a large outer dimension, and the existing optical terminal board is high-density. Could not be used in place of the optical connector placed in.

Further, the connecting portion 1 with the optical fibers 1a and 1b
Since both 1a and 11b are plug-type connectors, they cannot be inserted as an adapter between the existing optical terminal board and the optical fiber.

The present invention solves the problems of the above-mentioned prior art, enables accurate and reliable measurement of the direction and intensity of an optical signal, and provides an existing high-density mounted optical terminal board and optical fiber connector. An optical signal monitoring device that can be inserted as an adapter between the two.

[0020]

[Means for Solving the Problems]

In order to solve the above-mentioned problems, a first invention of the present invention is to insert an optical signal monitoring device into an optical transmission line and to partially transmit an optical signal transmitted to this optical transmission line. Is detected by branching, and an optical signal detector that outputs an electrical signal corresponding to the intensity of the detected optical signal from a terminal, and the terminal of the optical signal detector is connected through a cable for connection, And an optical signal display for displaying the state of the optical signal in the optical transmission line based on the electric signal output from the signal detector.

In a second invention, the optical signal detector in the first invention is a receptacle type first connector for connecting a plug type connector on an optical fiber side in an optical transmission line, and the optical transmission line in the optical transmission line. A plug-type second connector for connecting to the receptacle-type connector on the side of the optical terminal board, and this optical signal for branching the optical signal propagating in the optical fiber connecting the first and second connectors It is provided with a branching portion which is provided at a predetermined angle with respect to the optical axis of the signal and which allows most of the optical signal to pass therethrough and specularly reflects a part thereof.

Further, the optical signal detector detects an optical signal which is propagated from the first connector to the branch portion and specularly reflected by the branch portion, and the electrical signal corresponding to the intensity of the detected optical signal is detected. A first detection unit that outputs a signal, and an optical signal that propagates from the second connector to the branch unit and is specularly reflected by the branch unit, and an electrical signal corresponding to the intensity of the detected optical signal. To the first and second detectors for outputting test light directly to the first and second detectors, and the first and second detectors. A terminal for inputting and outputting an electric signal output from a detection part and an electric signal for driving the first and second light emitting parts, the first and second connectors, the terminal, the branch part, The first and second detection units, and the first and second light emitting units And a housing for turned into incorporate.

Further, the optical signal display is provided with the first and second optical signals.
Analog / digital (hereinafter referred to as "A / D") that converts the electrical signal supplied from the detector of
The conversion unit, the determination unit that determines the propagation direction of the optical signal propagating in the optical fiber based on the intensity of the light converted into the digital value by the A / D conversion unit, and the determination unit It is provided with a display section for displaying the propagation direction and the intensity of light in this propagation direction, and a test section for driving the first and second light emitting sections of the optical signal detector during a test.

According to the first and second aspects of the invention, since the optical signal monitoring device is constructed as described above, the following operation is performed.

For example, the second connector of the optical signal detector is connected to the receptacle type connector provided on the optical terminal board, and the optical fiber side plug type connector is connected to the first connector of the optical signal detector. Connecting. Further, an optical signal indicator is connected to the terminal of the optical signal detector via a connecting cable. Thereby, a part of the optical signal transmitted between the optical terminal board and the optical fiber is branched and detected by the optical signal detector. Then, an electric signal corresponding to the intensity of the detected optical signal is output from the terminal of the optical signal detector and given to the optical signal display via the cable for connection. The optical signal indicator displays the state of the optical signal in the optical transmission line based on the electrical signal output from the optical signal detector.

According to a third aspect of the present invention, an optical signal monitoring device is inserted in an optical transmission line, and an optical branching device for branching and outputting a part of an optical signal transmitted through the optical transmission line, and the optical branching device. An optical signal detector that detects a part of the optical signal output from the branching device and outputs an electrical signal according to the intensity of the detected optical signal, and based on the electrical signal output from the optical signal detector And an optical signal indicator for displaying the state of the optical signal in the optical transmission line.

In the fourth invention, the optical branching device in the third invention comprises a receptacle-type first connector for connecting a plug-type connector on the optical fiber side in the optical transmission line, and an optical fiber in the optical transmission line. A plug-type second connector for connecting to the receptacle-type connector on the terminal board side, and this optical signal for branching the optical signal propagating in the optical fiber connecting the first and second connectors A branch portion that is provided at a predetermined angle with respect to the optical axis and that allows most of the optical signal to pass through and specularly reflects a part of the optical signal; and the specular reflection from the first connector to the branch portion. And a housing having a second through hole for outputting the optical signal to the outside, and a second through hole for outputting the optical signal which is propagated from the second connector to the branch portion and specularly reflected to the outside. ing.

The optical signal detector detects the optical signal output from the first through hole of the optical branching device and outputs an electric signal corresponding to the intensity of the optical signal, and the optical detector. And a second detector that detects an optical signal output from the second through hole of the branching device and outputs an electrical signal corresponding to the intensity of the optical signal. Further, the optical signal indicator converts the electric signal given from the first and second detection units into a digital value A.
A / D converter, a discriminator that discriminates the propagation direction of an optical signal propagating in the optical fiber based on the intensity of light converted into a digital value by the A / D converter, and the discriminator. And a display unit for displaying the intensity of light in this propagation direction.

According to the third and fourth aspects of the invention, the following operations are performed.

For example, the second connector of the optical branching device is connected to the receptacle type connector provided on the optical terminal board,
A plug-type connector on the optical fiber side is connected to the first connector of this optical branching device. Further, in order to detect the optical signal output from the optical branching device, the first and second detecting parts of the optical signal detecting device are arranged so as to coincide with the first and second through holes of this optical branching device. set. As a result, part of the optical signal transmitted between the optical terminal board and the optical fiber is branched by the optical branching device and detected by the optical signal detector. Then, an electric signal corresponding to the intensity of the detected optical signal is output from the optical signal detector and given to the optical signal display. The optical signal indicator displays the state of the optical signal in the optical transmission line based on the electrical signal output from the optical signal detector.

[0032]

DETAILED DESCRIPTION OF THE INVENTION

(First Embodiment)

FIG. 1 is a block diagram of an optical signal monitoring apparatus showing a first embodiment of the present invention.

This optical signal monitoring device is inserted between the plug-type connector 1a on the optical fiber 1 side and the receptacle-type connector 2a on the optical terminal board 2 side to transmit the light transmitted through the optical transmission line. It monitors the direction and intensity of the signal, and is composed of an optical signal detector 20, an optical signal display 40, and a connection cable 60 connecting the optical signal detector 20 and the optical signal display 40.

Here, the optical terminal board 2 is installed at a wiring station or a relay station, and is a space for accommodating a spare optical fiber or a space for fusing and connecting the optical fibers. And a connector connection portion for easily performing wiring connection or wiring change by a connector. A plurality of receptacle-type connectors 2a are arranged in parallel at the connector connecting portion so that a large number of optical fibers can be connected.

The optical signal detector 20 branches and detects a part of the optical signal transmitted to the optical transmission line and outputs an electric signal according to the intensity of the detected optical signal. It has a receptacle-type connector 21 for inserting the 1-side connector 1a and a plug-type connector 22 for inserting into the connector 2a on the optical terminal board 2 side. Further, the optical signal detector 20 has a terminal 23 for connecting the connector 61 of the connection cable 60, an optical detection circuit for branching the optical signal and outputting an electric signal according to its intensity, and the like. The connector 21 and 22, the terminal 23, the photodetection circuit, and the like are integrally formed in the housing 24.

On the other hand, the optical signal indicator 40 is a portable measuring instrument that displays the state of the optical signal in the optical transmission line based on the electric signal output from the terminal 23 of the optical signal detector 20. On the front panel of the optical signal display 40, switches (SW) 41, 42, 43, 4 for setting measurement conditions and the like are provided.
4. LEDs 45, 46a, 46b, 47, 48a, 48 which are display units for displaying the setting state, signal state, etc.
b, a 7-segment type display unit 49 for displaying the measurement result by a numerical value and the like are arranged. In addition, the optical signal indicator 4
The case 0 is provided with a connector 50 for connecting the connector 62 on the side of the connection cable 60, and in this case, as will be described later, a measurement circuit including a microcomputer and the like are housed.

FIG. 3 is a sectional view of the optical signal detector shown in FIG.

The optical signal detector 20 includes a connector 21,
22 and the like are integrally formed with a housing 24.
The housing 24 is a case made of engineering plastic or the like that is precisely formed and has a strong light shielding property. The through hole 2 for arranging the optical transmission line in the center of the housing 24 is used.
4X is provided, and the connector 2 is provided on both sides of the through hole 24X.
1, 22 are formed. In addition, the housing 24 is provided with an internal space 24Y in which a light detection circuit such as a light receiving element is arranged in order to detect the light branched in the optical transmission path.

Inside the through hole 24X, the through hole 24
A sleeve 25 having an outer diameter substantially equal to the inner diameter of X is housed. The sleeve 25 is, for example, a metal plate of about 0.5 mm formed in a cylindrical shape, and the diameter thereof can be finely adjusted by an axial slit.
At the center of the sleeve 25, the internal space 24 of the housing 24
Through holes 25a and 25b for guiding a part of the optical signal to the internal space 24Y are provided at positions corresponding to Y.

Inside the sleeve 25, optical fibers 27a and 27b protected by ferrules 26a and 26b are inserted from both ends thereof. Ferrule 26
Reference characters a and 26b are tubular members formed of a light-transmitting material such as glass for reinforcing the optical fibers 27a and 27b and performing accurate alignment. The optical fibers 27a and 27b are respectively inserted into the ferrules 26a and 26b and fixed with an adhesive or the like,
Along with these ferrules 26a and 26b, the bifurcated surface thereof is polished so as to form a predetermined angle (for example, 45 °). In addition, the connector 2 of the optical fibers 27a and 27b
The end faces on the 1 and 22 sides have ferrules 26a and 26, respectively.
Along with b, it is polished to be exactly 90 °.

The branching surfaces of the optical fibers 27a and 27b protected by the ferrules 26a and 26b are in surface contact with each other so that no gap is formed at the central portion of the sleeve 25 with the branching film 28, which is a branching portion, interposed therebetween. The branch film 28 is formed by evaporating a metal film on a polyimide film, for example, and allows most of the optical signals to pass therethrough and specularly reflects some of the optical signals.

A circuit board 29 is provided on the side surface of the housing 24.
a and 29b are fixed. Inside the circuit board 29a, a terminal 23 for connecting the connection cable 60 and a photodetection circuit such as a PD 30a as a detection unit and an LED 31a as a light emission unit are mounted. Also, the circuit board 29b
A photo detection circuit such as the PD 30b and the LED 31b is mounted inside the.

The PD 30a selects the branching film 2 from among the optical signals transmitted from the optical fiber 27a side to the optical fiber 27b side.
The optical signal reflected by 8 is detected. P
D30b is an optical fiber 27a from the optical fiber 27b side.
Among the optical signals transmitted to the side, the optical signal reflected by the branch film 28 is detected. In addition, LED31
a and 31b are for checking the detection function,
Light for testing is given to the PDs 30a and 30b.

FIG. 4 is a block diagram showing an example of the circuit configuration of FIG.

The optical signal detector 20 includes a PD 30a for detecting a part of the optical signal incident from the optical fiber 1,
LED 31 for giving test light to this PD 30a
a. Further, this optical signal detector 20 is a P for detecting a part of the optical signal incident from the optical terminal board 2.
It has a D30b and an LED 31b for giving a test light to the PD 30b. On the output side of the PDs 30a and 30b, an amplifier 32a for amplifying the signals output from the PDs 30a and 30b to a predetermined level is provided.
32b are respectively connected. Amplifiers 32a, 32
The output signal of b is output from the terminal 23. Further, a test signal for driving the PDs 31a and 31b, and a power supply voltage + V for the amplifiers 32a and 32b.
CC and -VCC are supplied from the terminal 23.

On the other hand, the optical signal indicator 40 has a power source unit 51 such as a battery, and the optical signal detector 20 and the optical signal indicator 4 are connected from the power source unit 51 through the power switch 41.
The necessary power supply voltages + VCC and -VCC are supplied inside 0. In addition, the power supply voltage + VCC is supplied to the LED 45 for displaying the power supply, and the LED of the optical signal detector 20 is passed through the test switch 44, which is a test unit.
It is designed to be output as a test signal for 31a and 31b.

The optical signal display 40 has a microcomputer composed of an input port 52, a CPU (central processing unit) 53 as a discriminating section, an output port 54, and the like. Is the optical signal detector 2
The optical signals detected by the PDs 30a and 30b of 0 are given. The input port 52 is provided with an A / D converter, and the electric signal supplied from the optical signal detector 20 is converted into digital data according to the intensity of the optical signal and supplied to the CPU 53.

Further, at the input port 52, the start of measurement
A measurement switch 42 for instructing termination, a selection switch 43 for selecting the wavelength (for example, 1.31 μm or 1.55 μm) of the optical signal to be measured, etc. are connected, and the measurement conditions specified by these switches 42, 43 are connected. Are provided to the CPU 53.

An output port 54 is connected to the CPU 53, and an LE for status display is connected via this output port 54.
A display unit 49 for numerically displaying D46 to D48 and the optical signal level of the measurement result is driven.

Next, the operation will be described.

For example, assume that an optical signal is propagated from the optical fiber 1 to the optical terminal board 2. At this time, a part of the propagated optical signal is part of the branch film 28 of the optical signal detector 20.
It is branched by, passes through the through hole 25a, and is incident on the PD 30a. Thereby, the incident light is detected by the PD 30a, and a voltage corresponding to the intensity of the incident light is output and given to the amplifier 32a. The electric signal amplified to a predetermined level by the amplifier 32a is output from the terminal 23 to the optical signal display 40 via the connection cable 60.

The electric signal given to the optical signal display 40 is converted into the intensity of light by a digital value at the input port 52 and held.

At the same time, the optical signal is detected by the PD 30b. However, at this time, since there is almost no light output through the through hole 25b, the intensity of light detected by the PD 30b is weak, and the output voltage is extremely small. Therefore, an extremely small voltage is input to the input port 52, and the intensity of light according to the digital value is held.

Next, P held in the input port 52
The two light intensities corresponding to D30a and 30b are
It is read out by 53 and compared. When the difference between the two light intensities exceeds the reference value, the LED 46 indicating the direction of the optical signal is output from the CPU 53 via the output port 54.
a is turned on. Further, the intensity of light detected by the PD 30a is numerically displayed on the display unit 49 from the CPU 53 via the output port 54.

When an optical signal is propagated from the optical terminal board 2 to the optical fiber 1, a large voltage is generated in the PD 30b and an extremely small voltage is generated in the PD 30a. As a result, according to the determination of the CPU 53, the LED 46b is turned on and the intensity of the light detected by the PD 30b is numerically displayed on the display unit 49.

Since the wavelength of the optical signal propagating through the optical transmission line is 1.31 μm or 1.55 μm, the wavelength is selected by the selection switch 43. Selection switch 4
The signal No. 3 is read by the CPU 53 via the input port 52. As a result, the CPU 53 corrects the intensity of the optical signal according to the selected wavelength, and the display unit 49
Is displayed numerically.

By operating the test switch 44 of the optical signal display 40, the LE in the optical signal detector 20 is operated.
D31a and 31b can be selected and lighted.
For example, by tilting the test switch 44 to the A side, L
The ED 31a is turned on and the light is incident on the PD 30a. As a result, the LED 46a of the optical signal display 40 is turned on, and the intensity of propagating light assumed at that time is displayed on the display unit 49.

As described above, the optical signal monitoring device of the first embodiment has the following advantages.

(1) Since the optical signal detector 20 and the optical signal display 40 are separated, the optical signal detector 20 inserted in the optical transmission line can be miniaturized. Further, the optical signal detector 20 has a receptacle type connector 21 to which the connector 1a on the optical fiber 1 side can be directly connected and a plug type connector 22 to be directly connected to the connector 2a on the optical terminal board 2 side. There is. As a result, the connector 2a can be mounted as it is as an adapter on the optical terminal board 2 on which the connectors 2a are mounted with high density.

(2) In the optical signal detector 20 required for each optical transmission line, the functions of suppressing the minimum functions such as optical detection and judging and displaying the intensity of the optical signal can be commonly used. The signal display 40 is provided. Therefore, the cost of the optical signal detector 20 is reduced, and the cost of the entire equipment can be suppressed.

(3) The optical signal display 40 has an input port 52 and a CPU 53 for converting the intensity of the optical signal detected by the optical signal detector 20 into a digital value for processing. As a result, the direction and intensity of the optical signal can be measured accurately and reliably.

(4) Since the optical signal display 40 is portable and small in size, it is easy to carry and the workability and convenience are improved during maintenance.

(Second Embodiment)

FIG. 5 is a block diagram of an optical signal monitoring apparatus showing a second embodiment of the present invention. Elements common to those in FIG. 1 are designated by common reference numerals.

This optical signal monitoring device is inserted between the optical fiber 1 and the optical terminal board 2 to monitor the direction and strength of the optical signal transmitted through the optical transmission line. ,
It is composed of an optical signal detector 80 and an optical signal display 40A.

The optical branching device 70 branches a part of the optical signal transmitted to the optical transmission line, and has a receptacle type connector 71 for inserting the connector 1a on the optical fiber 1 side and the optical terminal board 2. It has a plug-type connector 72 to be inserted into the side connector 2a. Further, the optical branching device 70 has through holes 73a and 73b for outputting the branched optical signal to the outside.

The optical signal detector 80 detects the optical signal branched and output by the optical branching device 70 and outputs an electric signal according to the intensity of the detected optical signal.
It has a U-shaped member 81 formed so as to sandwich the 0 through holes 73a and 73b from the outside. Inside the U-shaped member 81, PDs 82a and 82b that receive the optical signals output from the through holes 73a and 73b of the optical branching device 70 and convert the optical signals into electrical signals corresponding to the intensities thereof are provided. The optical signal detector 80 is adapted to be connected to the optical signal display 40A by a cable 84 and a connector 85.

The optical signal display 40A includes an optical signal detector 80.
The state of the optical signal in the optical transmission line is displayed based on the electric signal output from the optical transmission line. On the front panel of the optical signal display 40A, switches 41, 43, 55 for setting power on / off, measurement conditions, etc., and LEDs 46a, 46b, 47, 4 which are display parts for displaying states, etc.
8a, 48b, 57, and a 7-segment type display unit 49 for displaying the measurement results by numerical values are arranged. Further, in the case of the optical signal display 40A, the optical signal detector 8
A connector 50 for connecting the 0-side connector 85,
A DC jack 58 for receiving DC power from an AC adapter or the like is provided. Further, the optical signal display 40A
As will be described later, a measuring circuit including a microcomputer and the like are housed in the case.

FIG. 6 is a sectional view of the optical branching device in FIG.

This optical branching device 70 includes connectors 71 and 72.
Etc. are integrally formed with a housing 73. The housing 73 is a case made of engineering plastic or the like that is precisely formed and has a strong light-shielding property, and a through hole 73X for disposing an optical transmission line in the center of the housing 73.
Are provided on both sides of the through hole 73X.
72 is formed. Further, the housing 73 is provided with through holes 73a and 73b for outputting a part of the optical signal branched in the optical transmission path to the outside.

Inside the through hole 73X, the through hole 73
A sleeve 74 having an outer diameter approximately equal to the inner diameter of X is housed. The sleeve 74 is, for example, a metal plate of about 0.5 mm formed in a cylindrical shape, and the diameter thereof can be finely adjusted by an axial slit.
Through hole 73a of housing 73 at the center of sleeve 74,
Through holes 74a and 74b for guiding a part of an optical signal to the through holes 73a and 73b are provided at positions corresponding to 73b.

Inside the sleeve 74, optical fibers 76a and 76b protected by ferrules 75a and 75b are inserted from both ends thereof. Ferrule 75
Reference characters a and 75b are tubular members formed of a light-transmitting material such as glass for reinforcing the optical fibers 76a and 76b and performing accurate alignment. The optical fibers 76a and 76b are respectively inserted into the ferrules 75a and 75b and fixed with an adhesive or the like,
Along with these ferrules 75a and 75b, the bifurcated surface is polished so as to form a predetermined angle (for example, 45 °). In addition, the connector 7 of the optical fibers 76a and 76b
The end faces on the 1,72 side have ferrules 75a, 75, respectively.
Along with b, it is polished to be exactly 90 °.

The branching surfaces of the optical fibers 76a and 76b protected by the ferrules 75a and 75b are in surface contact with each other so that no gap is formed at the central portion of the sleeve 74 with the branching film 77, which is a branching portion, interposed therebetween. The branch film 77 is formed by evaporating a metal film on a polyimide film, for example, and allows most of the optical signals to pass therethrough and specularly reflects some of the optical signals. As a result, the connector 7 on the optical fiber 1 side
A part of the optical signal incident from 1 is reflected by the branching film 77, passes through the through holes 74a and 73a, is output to the outside, and a part of the optical signal incident from the connector 72 on the optical terminal board 2 side. Is reflected by the branch film 77, passes through the through holes 74b and 73b, and is output to the outside.

FIG. 7 is a block diagram showing an example of the circuit configuration of FIG.

The optical signal detector 80 includes a PD 82a for detecting an optical signal input from the optical fiber 1 side and output from the through hole 73a of the optical branching device 70, and an optical signal input from the optical terminal board 2 side. It has a PD 82b for detecting a signal. These PDs are provided on the output side of the PDs 82a and 82b.
Amplifiers 83a and 83b for amplifying the electric signals output from 82a and 82b to a predetermined level are respectively connected.

The output signals of the amplifiers 83a and 83b are output from the connector 85 via the cable 84 to the optical signal display 40A.
To be given to. In addition, PD82a, 8
The power supply voltages + VCC and −VCC for driving 2b and the amplifiers 83a and 83b are supplied from the optical signal display 40A side via the connector 85.

The optical signal indicator 40A is a power source unit 5 such as a battery.
1, the power supply unit 51 supplies the power supply voltages + VCC and -VCC required inside the optical signal detector 80 and the optical signal display 40A via the switch 41. Further, the power supply voltage + VCC is supplied to the measurement display LED 47 and the low voltage detection unit 56.

The low voltage detector 56 turns on the LED 57 and displays a LOW-BATT warning when the power supply voltage + VCC drops below a certain voltage. Further, the optical signal display 40A has a power supply voltage of + VCC,-
It has a DC jack 58 connected to VCC, and can supply power supply voltages + VCC and -VCC from an external AC adapter or the like via this DC jack 58.

The optical signal display 40A includes an input port 52, a CPU 53 as a discriminating section, and an output port 54.
And a PD 82 of the optical signal detector 80 is connected to the input port 52.
The signals detected by a and 82b and converted into electric signals are given. The input port 52 is provided with an A / D converter, and an electric signal supplied from the optical signal detector 80 is converted into digital data corresponding to the intensity of the optical signal and supplied to the CPU 53.

Further, the input port 52 has a wavelength (for example, 1.31 μm or 1.55 μm) of the optical signal to be measured.
m), switches 43 and 55 for selecting HIGH and LOW of the light receiving level are connected, and these switches 43 and
The measurement condition designated by 55 or the like is given to the CPU 53.

Further, an output port 54 is connected to the CPU 53, and an LE for status display is connected via this output port 54.
D46a, 46b, 48a, 48b and a display unit 49 for numerically displaying the level of the optical signal of the measurement result are driven.

Next, the operation will be described.

Prior to the monitoring, the optical branching device 70 is inserted between the connector 1a of the optical fiber 1 to be monitored for the optical signal and the connector 2a of the optical terminal board 2 corresponding thereto.
Further, the U-shaped member 81 of the optical signal detector 80 is sandwiched so that the PDs 82a and 82b of the optical signal detector 80 face the through holes 73a and 73b of the optical branching device 70, respectively. Further, the connector 85 of the optical signal detector 80 is connected to the connector 50 of the optical signal display 40A. After the above preparations are completed, the switch 41 of the optical signal display 40A is turned on.

For example, when an optical signal is propagated from the optical fiber 1 toward the optical terminal board 2, a part of the propagated optical signal is branched by the branching film 77 of the optical branching device 70 and the through hole is formed. After passing through 74a and 73a, it is incident on the PD 82a of the optical signal detector 80. Thereby, the PD 82a detects the incident light, outputs a voltage corresponding to the intensity of the incident light, and supplies the voltage to the amplifier 83a.

The electric signal amplified by the amplifier 83a to a predetermined level is transmitted through the cable 84 to the optical signal display 40A.
Is output to. The electric signal given to the optical signal display 40A is converted into a light intensity by a digital value at the input port 52 and is held.

At the same time, the PD 8 of the optical signal detector 80
An optical signal is detected also in 2b. However, at this time, since almost no light is output through the through holes 74b and 73b of the optical branching device 70, the intensity of light detected by the PD 82b is weak and the output voltage is extremely small. Therefore, an extremely small voltage is input to the input port 52, and the intensity of light according to the digital value is held.

Next, P held in the input port 52
The intensity of two lights corresponding to D82a and 82b is the CPU
It is read out by 53 and compared. When the difference between the two light intensities exceeds the reference value, the LED 46 indicating the direction of the optical signal from the CPU 53 via the output port 54.
a is turned on. Further, the intensity of the light detected by the PD 82a is transmitted from the CPU 53 via the output port 54 to the display unit 4
Numerical value is displayed on 9.

When an optical signal is propagated from the optical terminal board 2 to the optical fiber 1, a large voltage is generated in the PD 82b and an extremely small voltage is generated in the PD 82a. As a result, according to the determination of the CPU 53, the LED 46b is turned on and the intensity of the light detected by the PD 82b is displayed on the display unit 49 as a numerical value.

The wavelength of the optical signal propagating through the optical transmission line is
Since there are 1.31 μm and 1.55 μm types, the wavelength is selected by the selection switch 43. The signal of the selection switch 43 is read by the CPU 53 via the input port 52. As a result, the intensity of the optical signal is corrected by the CPU 53 according to the selected wavelength, and is displayed on the display unit 49 as a numerical value.

Further, the switch 55 of the optical signal display 40A
The light receiving level can be switched between HIGH and LOW. As a result, the A / D in the input port 52
The level of the input signal to the converter is switched, and the intensity of the optical signal can be read accurately.

For example, when the switch 55 is set to HIGH, the measurement range is −45 to −15 dBm, and if the intensity of the optical signal is in this range, the numerical value is displayed on the display unit 49. When the intensity of the optical signal is -14 dBm or more, "HH" is displayed on the display unit 49, and -46 is displayed.
When it is less than or equal to dBm, "---" is displayed and the LED 48a is turned on. When the switch 55 is set to LOW, the measurement range is −25 to 6 dBm, and if the intensity of the optical signal is in this range, the numerical value is displayed on the display unit 49. Then, the intensity of the optical signal is -26d.
When it is Bm or less, "LL" is displayed on the display unit 49, when it is 7 dBm or more, "---" is displayed and the LED 48b is turned on.

As described above, the optical signal monitoring apparatus according to the second embodiment has the following advantages in addition to the advantages (3) and (4).

(5) Optical splitter 70 and optical signal detector 8
Since 0 and the optical signal display 40A are separated, it is possible to further reduce the size of the optical branching device 70 inserted in the optical transmission line. Further, the optical branching device 70 has a receptacle-type connector 71 to which the connector 1a on the optical fiber 1 side can be directly connected, and a plug-type connector 72 for directly connecting to the connector 2a on the optical terminal board 2 side. . As a result, the connector 2a can be mounted as it is as an adapter on the optical terminal board 2 on which the connectors 2a are mounted with high density.

(6) Optical splitter 70 required for each optical transmission line
Is a function that only suppresses the light for monitoring, and the functions of converting an optical signal into an electric signal, determining the signal strength, and displaying are commonly used optical signal detector 80 and optical signal display 40A. I have it on my side. As a result, the cost of the optical branching device 70 can be reduced, and the cost of the entire facility can be further suppressed.

The present invention is not limited to the above embodiment, and various modifications can be made. Examples of this modification include the following.

(A) Connector 2 of the optical signal detector 20
The shapes of the connectors 1, 72 of the optical splitters 1, 22 and the optical branching device 70 are not limited to those shown in the drawings. It is necessary to use a connector that corresponds to the connector 2a of the optical terminal board 2 that is actually applied.

(B) Housing 2 of optical signal detector 20
4, the structure of the housing 73 of the optical branching device 70, and the like are not limited to those illustrated.

(C) In the illustrated optical signal display 40,
Although the connector 50 for connecting the connector 62 of the connection cable 60 is provided, the connection cable 60 may be fixedly connected to the optical signal display 40 without the connector. This enables cost reduction.

(D) The types and arrangements of the switches and LEDs on the panel in the optical signal displays 40 and 40A are not limited to those illustrated. Further functions can be added as needed.

(E) The optical signal detector 20 has a PD 30
an amplifier 32a for amplifying the output signals of a and 30b,
Although 32b is provided, these amplifiers 32a and 32b are not necessary when the output signals of these PDs 30a and 30b are large compared to noise or the like. Amplifiers 32a and 32b
By eliminating the above, it becomes unnecessary to supply the power supply voltages + VCC and −VCC, and the optical signal detector 20 can be further downsized and reduced in cost. Optical signal detector 80
83a, 8 for PDs 82a, 82b in
The same applies to 3b.

(F) The circuit configurations of the optical signal indicators 40 and 40A are not limited to those shown in the drawings. For example, LED
A liquid crystal display or the like may be used instead of the display unit 46, the display unit 49, or the like. Thereby, power consumption can be reduced.

[0104]

【The invention's effect】

As described in detail above, according to the first invention, an optical signal detector for inserting an optical signal monitoring device into an optical transmission line to detect an optical signal, and the optical signal detector And an optical signal indicator that displays the state of the optical signal based on the output electrical signal. As a result, an optical signal can be monitored by connecting as an adapter between the existing high-density mounted optical terminal board and the optical fiber connector.

According to the second aspect of the invention, the optical signal detector detects two branches of two connectors for connecting between the optical fiber of the optical transmission line and the connector of the optical terminal board and bidirectional optical signals. In addition to the branching section and the detecting section, a light emitting section for outputting test light is included. The optical signal display is connected to the optical signal detector with a cable to discriminate and display the propagation direction and intensity of the optical signal, an A / D conversion unit, a determination unit, a display unit, and a test unit. And so on. As a result, the direction and intensity of the optical signal can be measured accurately and reliably.

According to the third invention, an optical signal monitoring device is provided,
An optical branching device that is inserted into an optical transmission line to branch an optical signal, an optical signal detector that detects the optical signal branched by this optical branching device and converts it into an electrical signal, and an output from this optical signal detector And an optical signal indicator that displays the state of the optical signal based on the electric signal. As a result, the optical branching device is further simplified, and the optical signal can be monitored by using this optical branching device even in the optical terminal board mounted with higher density.

According to the fourth aspect of the invention, the optical branching device has two connectors for connecting between the optical fiber of the optical transmission line and the connector of the optical terminal board, and outputs an optical signal for each branching direction. It has two through holes. The optical signal detector includes a detector that converts the optical signal output from the optical branching device into an electric signal. In addition, the optical signal display includes an A / D conversion unit for determining and displaying the propagation direction and intensity of the optical signal, a determination unit,
And has a display portion. As a result, the direction and intensity of the optical signal can be measured accurately and reliably.

[Brief description of drawings]

FIG. 1 is a configuration diagram of an optical signal monitoring device according to a first embodiment of the present invention.

FIG. 2 is a configuration diagram of a conventional photodetector.

FIG. 3 is a sectional view of the optical signal detector in FIG.

FIG. 4 is a block diagram showing an example of the circuit configuration of FIG.

FIG. 5 is a configuration diagram of an optical signal monitoring device according to a second embodiment of the present invention.

6 is a cross-sectional view of the optical branching device in FIG.

7 is a block diagram showing an example of the circuit configuration of FIG.

[Explanation of symbols]

1, 27a, 27b Optical fiber 1a, 2a, 21, 22, 71, 72 connectors 2 optical terminal board 20,80 Optical signal detector 23 terminals 24 housing 28,77 branched membrane 30a, 30b PD (photodiode) 31a, 31b LED (light emitting diode) 40,40A Optical signal indicator 44 test switch 49 Display 52 input ports 53 CPU (Central Processing Unit) 54 output ports 60 connection cable 70 Optical splitter 73a, 73b through hole

   ─────────────────────────────────────────────────── ─── Continued front page    (72) Inventor, Kyoji Hayakawa             Aichi Prefecture Okazaki City Tozaki-cho character Daido East 7 Chubu             Electric power Co., Ltd. Okazaki branch (72) Inventor Naoshi Nishigaki             Aichi Prefecture Okazaki City Tozaki-cho character Daido East 7 Chubu             Electric power Co., Ltd. Okazaki branch (72) Inventor Tatsuya Sugiyama             1-15 Higashino, Ishinomakihonmachi, Toyohashi City, Aichi Prefecture             Chubu Electric Power Co., Ltd. Toyohashi Electric Power Center (72) Inventor Yuki Fukumitsu             1-15 Higashino, Ishinomakihonmachi, Toyohashi City, Aichi Prefecture             Chubu Electric Power Co., Ltd. Toyohashi Electric Power Center (72) Inventor Kazuhiro Bucheon             1 of 48 Oshimizu, Oshimizu Town, Toyota City, Aichi Prefecture             Chubu Electric Power Co., Ltd. Toyota Electric Power Center (72) Inventor Norio Konishi             Aichi Prefecture Okazaki City Idamachi 4-chome 187 shares             Ceremony Company C Tech Okazaki Branch (72) Inventor Mitsuru Inoue             Stock Market Association, 4-3 Osaki, Shinagawa-ku, Tokyo             Inside Sankosha (72) Inventor Akiichi Fujimoto             Stock Market Association, 4-3 Osaki, Shinagawa-ku, Tokyo             Inside Sankosha (72) Inventor Mitsunori Kaneko             5-5-23 Osaki, Shinagawa-ku, Tokyo Hirose             Electric Co., Ltd. F-term (reference) 2H036 QA02 QA57 QA59                 2H037 AA01 BA02 BA04 BA11 BA13                       DA03 DA04 DA06                 5K042 CA10 DA16 EA15 FA21 GA06                       HA02 JA01                 5K102 AA45 LA26 LA41 MH07 MH11                       MH22 PH49 RB02

Claims (4)

[Claims] 1. An optical signal which is inserted into an optical transmission line, branches a part of an optical signal transmitted to the optical transmission line, detects the optical signal, and outputs an electric signal corresponding to the intensity of the detected optical signal from a terminal. An optical signal detector to be connected to a terminal of the optical signal detector via a cable for connection, and the state of the optical signal in the optical transmission line based on an electric signal output from the optical signal detector An optical signal monitoring device comprising an optical signal display for displaying. 2. The optical signal detector comprises a receptacle-type first connector for connecting a plug-type connector on the optical fiber side of the optical transmission line, and an optical terminal board-side receptacle type connector on the optical transmission line. A plug-type second connector for connecting to the connector, and an optical axis of the optical signal for branching the optical signal propagating in the optical fiber connecting the first and second connectors A branch provided at a predetermined angle to allow most of the optical signal to pass therethrough and specularly reflect a part of the optical signal; and light propagated from the first connector to the branch and specularly reflected by the branch. A first detection unit that detects a signal and outputs an electric signal according to the intensity of the detected optical signal; and an optical signal that is propagated from the second connector to the branch unit and specularly reflected by the branch unit. Detect A second detector for outputting an electric signal according to the intensity of the detected optical signal, and first and second detectors for directly applying test light to the first and second detectors, respectively. And a terminal for inputting and outputting an electric signal output from the first and second detection units and an electric signal for driving the first and second light emission units, A second connector, the terminal, the branch portion,
A housing for integrally incorporating the first and second detection units and the first and second light emitting units, wherein the optical signal display is provided from the first and second detection units. An analog / digital converter for converting an electric signal to be converted into a digital value, and a propagation direction of an optical signal propagating in the optical fiber based on the intensity of the light converted into the digital value by the analog / digital converter. A discriminating section, a display section for displaying the propagation direction discriminated by the discriminating section and the intensity of light in this propagation direction, and a test section for driving the first and second light emitting sections of the optical signal detector at the time of a test. The optical signal monitoring device according to claim 1, further comprising: 3. An optical branching device which is inserted into an optical transmission line and branches a part of an optical signal transmitted to the optical transmission line and outputs the branched optical signal, and the optical signal output from the optical branching device. An optical signal detector that detects a part and outputs an electrical signal according to the intensity of the detected optical signal, and an optical signal in the optical transmission line based on the electrical signal output from the optical signal detector. An optical signal monitoring device comprising an optical signal display for displaying the status. 4. The optical branching device comprises a receptacle-type first connector for connecting a plug-type connector on the optical fiber side of the optical transmission line, and a receptacle-type connector on the optical terminal board side of the optical transmission line. A plug-type second connector for connecting the optical signal and a predetermined optical axis of the optical signal for branching the optical signal propagating in the optical fiber connecting the first and second connectors. And a branching portion that is provided at an angle of 1 to allow most of the optical signal to pass through and specularly reflects a portion of the optical signal, and outputs the specularly reflected optical signal propagated from the first connector to the outside. A first through hole and a housing having a second through hole for outputting an optical signal propagating from the second connector to the branch portion and specularly reflected to the outside, the optical signal detector comprising: , The light A first that detects an optical signal output from the first through hole of the branch and outputs an electric signal according to the intensity of the optical signal
And a second detection unit for detecting an optical signal output from the second through hole of the optical branching device and outputting an electric signal according to the intensity of the optical signal.
The optical signal display unit includes: an analog / digital conversion unit for converting an electric signal given from the first and second detection units into a digital value; and a digital value for the analog / digital conversion unit. A discriminating unit that discriminates the propagation direction of the optical signal propagating in the optical fiber based on the intensity of the light converted into, a propagation direction discriminated by the discriminating unit, and the intensity of light in this propagation direction are displayed. The optical signal monitoring device according to claim 3, further comprising a display unit.