JPH055322B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to an optical signal branching device in an optical waveguide.

[Conventional technology]

Figures 5 and 6 are, for example, published in Japanese Patent Application Laid-Open No. 62-73225.
This is a conventional optical branch communication device shown in the No. ``Optical Switch.''

In FIGS. 5 and 6, FIG. 5a shows a branching device of an optical switch, and a transmission prism 51 outputs light from an upper light input end 52 to a lower light output end 53. The light is transmitted through the B station 61 in the figure, through the lower optical input end 54, through the prism 51, through the upper optical output end 55, and to the optical switch 63 of the next C station 62. In this way, the optical signal from the A station 64 is transferred to the optical fiber 65.
The signal is then transmitted to the D station 66 through the network. During normal operation, each of the stations B, C, and D amplifies the optical signal to compensate for attenuation in the optical path. If a failure occurs in any of these stations, remove the prism 51 from the optical path above the optical switch 63 as shown in Figure 5b.
It is configured to transmit light to the next station without branching or amplifying the light.

[Problem that the invention seeks to solve]

This conventional optical switch (optical branching device) is configured as described above, so it requires the use of an optical transmission prism that is expensive and difficult to mass-produce for optical branching, and the optical amplification of each communication station. When the part breaks down,
As shown in FIG. 5b, since a driving mechanism is required to mechanically remove the transmission prism 51 from the main optical path, there is a problem that the apparatus becomes expensive and large.

[Means for solving problems]

In order to solve the above-mentioned problems, in this invention,
A porous photoelectric element is placed between waveguides such as optical fibers, the output of this element is amplified, the light emitting element is energized, and the light from this light emitting element is injected into the subsequent waveguide. It is.

[Effect]

With this configuration, the input optical signal is branched by the porous photoelectric element, amplified, and output from the light emitting element into the waveguide, so even if the light emitting element does not output the optical signal for some reason, the input optical signal is transmitted through the porous photoelectric element and output.

〔Example〕

This invention will be explained below by way of an example. In FIG. 1, a porous photoelectric element 1 is connected to a porous photoelectric element 1 that receives part of the light and transmits the other transmitted light as it is from the optical fiber 2, which is an upstream waveguide, to the optical fiber 3, which is a downstream waveguide. and the optical path of the downstream optical fiber. The porous photoelectric element is
It is connected to an electronic amplifier circuit 4, a constant voltage power supply 5, and an output drive transistor 6, and is configured to optically and electrically exchange a part of the optical signal from the upstream optical fiber, amplify it, and output it as a digital pulse from the transistor 6. ing. Its output is a light emitting element
It is connected to the cathode of the LED, LD, 7 through a current limiting resistor 8, and its anode is connected to a constant voltage power supply 5. Here, the light emitting element 7 transmits light to the downstream optical fiber 3 through a bonding material (means for injecting light into the waveguide) 11 having a refractive index between, for example, the refractive index of the core 9 and the cladding 10 of the optical fiber cable. It has the role of injecting.

Here, there is a concern about the phase shift between the light transmitted through the porous photoelectric element 1 of the optical fiber from the upstream and the optically amplified and injected light, but according to experiments, even when the response delay is 1 μS, the power output is 9600 bPS. It turns out that there is no problem with low-speed signal transmission.

In order to further reduce the size of this embodiment, as shown in FIG. 3, a porous photoelectric element 1, an electronic amplifier circuit 4,
By integrating the constant voltage power supply 5 and the output drive transistor 6 into a light receiving IC, 12, it is possible to combine the light receiving IC, 12, which is only 3 mm square, and the light emitting element 7, which is approximately 10 mm in size, making it possible to connect optical fibers. It is possible to provide an ultra-compact integrated optical branching device 13 having a structure. This can also be used as an optical branch connector.

Here, the function and method of use of this embodiment will be explained with reference to FIG.

The optical signal transmitted from the A station passes through the optical fiber 2 and reaches the optical branching device 13 of the B station. As mentioned above, the optical signal is received by the porous photoelectric element 1, self-amplified within the optical branching device, and transmitted to the downstream optical fiber 3.
A sufficiently high-quality optical signal is powerfully emitted and transmitted in the direction of the optical branching device 13 of the C station. Therefore, the signal can be directly transmitted to the D station by passing through the C station. Also, at station B, the output 14 of the photodetector IC passes through the buffer,
For example, the microcomputer 15 inputs the RD and decodes the signal. Furthermore, if the local station needs to send data to another station, it pulses the driver (driving circuit using an external signal) 16 from the TD output, and
If the signal is transmitted aiming at the idle time of the light emitting element 7
emits pulses and can transmit and communicate.

Here, if there is a failure in the electrical connection between the B station and the optical branching device 13 of the B station, for example, if there is a failure in the connection of the power supply Vcc, or if the light receiving IC or 12 light emitting element 7 fails, the A
The transmission signal from the station passes through the optical branching device of the B station,
If the C station is reached and the C station is alive, the next D
It can be transmitted one after another in the direction after the station.

Next, an example of the structure of the porous photoelectric element 1 is shown in FIG. Incident light 21 and transmitted light 22 of porous photoelectric element 1
The ratio can be freely selected depending on the number of minute holes 23, and the optimal ratio of received light and transmitted light can be set depending on the type of light emitting element 7, fiber, and transmission distance.

Further, as an application example of the present invention, it is also possible to provide an optical fiber that receives and transmits optical signals in both directions. In other words, if two porous photoelectric elements 1 in FIG.
It is possible to provide an optical branching connector that can receive not only an optical signal from the optical fiber 3 to the optical fiber 3 but also an optical signal in the opposite direction from the optical fiber 3 to the optical fiber 2. Therefore, by looping a single optical fiber from station A to station D in Figure 2, a bidirectional optical multibus capable of transmitting light to both the left and right loops can be provided at low cost, an epoch-making effect. There is.

〓Effects of the Invention〓 As described above, the present invention makes it possible to provide a small and inexpensive optical branching device without a mechanical drive unit, which can be used as a component to improve the reliability of signal transmission in an optical multi-bus system. can do.

[Brief explanation of the drawing]

Fig. 1 is a block diagram of one embodiment of the present invention, Fig. 2 is an explanatory diagram of the function and usage of the same embodiment, Fig. 3 is a block diagram of another embodiment, and Fig. 4 is a porous photoelectric element. FIG. 2 is a configuration diagram of an embodiment of the present invention. FIG. 5 is a block diagram of a conventional device, in which a shows a normal state and b shows a faulty state, and FIG. 6 is an explanatory diagram of the operation and usage of the conventional device. In the figure, 1 is a porous photoelectric element, 7 is a light emitting element, 1
1 is a means for injecting light into the waveguide, and the same reference numerals indicate the same or equivalent parts.

Claims (1)

[Scope of Claims] 1. An optical branching device characterized in that a porous photoelectric element that receives part of light and transmits part of light is disposed between waveguides such as optical fibers. 2. A member in which a porous photoelectric element that receives part of light and transmits part of the light is arranged between waveguides such as optical fibers, a means for amplifying the output of the porous photoelectric element, and a member that uses the means to amplify the output of the porous photoelectric element. a light emitting element to be energized;
An optical branching device comprising means for injecting light from the light emitting element into a subsequent waveguide. 3. The optical branching device according to claim 2, characterized in that a porous photoelectric element, a means for amplifying the output of the porous photoelectric element, and a power source thereof are integrated into a light receiving IC. 4. The optical branching device according to claim 2 or 3, characterized in that a drive circuit using an external signal is connected to the light emitting element.