JPH0464044B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Technical Field of the Invention] The present invention relates to an optical transmission device with an optical bypass mechanism suitable for use as a station in an optical communication network, for example.

[Technical background of the invention and its problems]

Conventionally, stations in an optical communication network are as shown in FIGS. 5 and 6.

First, the operation when used as a station will be explained with reference to FIG. This station is equipped with optical switch 1 as shown in the figure.
The optical switch 1 is composed of an optical transmitter 2 and an optical receiver 3, and the optical switch 1 receives an optical input signal from a first transmission line ₄₁ through a first optical input port ₅₁ , a prism 7, and a second output port. 6 ₂ , is input to the optical receiver 3 via the first optical fiber 9 ₁ and converted into an electrical signal.
When this station is operating, for example, as a relay station, the above-mentioned electrical signal is converted into an optical signal again by the optical transmitter 2, and is sent from the second optical fiber 9 ₂ to the second optical input port 5 ₂ . It is transmitted as optical output through the prism 7 and the first output port 6 ₁ to the second transmission line 4 ₂ and then transmitted to the subsequent station. In the figure, 8 is a drive mechanism for moving the prism 7.

If a system failure occurs in such a station, the prism 7 of the optical switch 1 is moved by the drive mechanism 8 to switch to the state shown in FIG.
the first optical input port 5 ₁ connected to the transmission line 4 _{2 of}
The optical input signal from the station is directly transmitted from the first output port 6 ₁ to the subsequent station via the second transmission line 4 ₂ .

Therefore, each station in such an optical communication network is a system that combines an optical switch 1, an optical transmitter 2, an optical receiver 3, and optical fibers ₉₁ and ₉₂ .

Therefore, the conventional system has the following problems.

First, when coupling the transmission lines 4 ₁ and 4 ₂ with the optical transmitter 2 and the optical receiver 3, the optical switch 1 via the prism 7 is involved, so the insertion loss of the optical switch 1 is added as is, resulting in transmission. The coupling loss to the paths 4 ₁ and 4 ₂ increases.

Secondly, in the optical switch 1, since the prism 7 is moved, the weight and external shape of the moving body become large, which is extremely disadvantageous for high-speed switching operation.

Thirdly, the number of parts constituting the system is large, requiring a large installation area, and lowering reliability.

[Purpose of the invention]

The present invention has been made in view of the above-mentioned problems, and provides an optical transmission device with an optical bypass mechanism that can particularly reduce coupling loss, enable high-speed switching operation, be compact and satisfy high reliability. is intended to provide.

[Summary of the invention]

That is, the present invention is an optical transmission device with an optical bypass mechanism that integrates an optical switch, an optical transmitter, and an optical receiver, and instead of switching the optical path using a prism or the like, one end is connected to the optical input port and the optical output port, respectively. An optical transmission device with an optical bypass mechanism is characterized in that an optical switch function can be realized by simultaneously moving the other ends of movable input and output optical fibers whose one ends are fixed so as to be coupled.

[Embodiments of the invention]

Next, the first embodiment of the present invention will be explained in FIGS. 1 and 2.
This will be explained using figures.

That is, in the case 14, which has a light input port 12 and a light output port 13 on opposite sides, which are connected to an optical connector of an external transmission line (not shown), there is an optical waveguide 17 made of, for example, a plastic fiber, and an optical transmitter. 18 and receiver 19 are fixed in a predetermined position, and the drive mechanism 15 is also fixed in a predetermined position. This drive mechanism 15 is provided with a U-shaped movable body 16 that moves linearly in the direction of arrow 22 within the housing 14 to a first position and a second position. In addition, one end 20 of a movable input fiber 20 is connected to the light input port 12 via a precision-machined cylindrical member 23.
The vicinity of b is fixed, and this movable input fiber 20
The vicinity of the other end 20a is fixed to the movable body 16. Similarly, a movable optical fiber 21 for emitting light is also connected to the light emitting port 13 via a cylindrical member 24 that is precisely machined.
The vicinity of one end 21b of the movable output optical fiber 21 is fixed, and the vicinity of the other end 21a of the movable output optical fiber 21 is fixed to the movable body 16.

With this structure, when the movable body 16 is in the first position, that is, the position shown in the figure, the movable fiber 20 for incidence
The optical axis of the movable body side end surface 20a of the optical waveguide 17 coincides with the optical axis of the movable body side end surface 21a of the optical waveguide 17, and the optical axis of the movable body side end surface 21a of the movable optical fiber for output 21 and the optical waveguide 1
The optical axes of the output end surfaces 17b of No. 7 coincide with each other. Therefore, the optical signal entering the light input port 12 exits from the light output port 13 as is. In other words, in this state, the optical transmission device has a bypass function.

When the movable body 16 is in the second position, the optical axis of the movable body side end surface 20a of the movable input optical fiber 20 and the optical axis of the light receiving element 26 of the optical receiver 19 coincide with each other, and the output movable optical fiber The optical axis of the end surface 21a of the movable body 21 and the optical axis of the light emitting element 25 of the optical transmitter 18 coincide.

At this time, an optical signal entering from the light input port 12 is converted into an electrical signal by the light receiving element 26 and output from an external terminal provided on the bottom surface of the device (not shown). Conversely, an electrical signal entering the external terminal is converted into an optical signal by the light emitting element 25 and output from the light output port 13.
In other words, in this state, the optical transmitter 18 and the optical receiver 1
9 is connected to an external transmission section. In this case as well, the part that causes optical loss until the electrical signal is converted into an optical signal and output from the light output port 13, or the part that causes optical loss until the optical signal that enters from the optical input port 12 is converted into an electrical signal is the optical Between the output port 13 and the movable optical fiber for output 21, between the movable optical fiber for output 21 and the light emitting element 25, or the light input port 1
2 and the movable input optical fiber 20, and between the movable input optical fiber 20 and the light receiving element 26. However, the connection loss between the optical fiber of the external transmission path and the movable optical fibers 20 and 21 at the light input port 12 and the light output port 13 is
By increasing the precision of 4, it can be made extremely small, so the external transmission line and light emitting/receiving element
The optical coupling loss between 5 and 26 is reduced, and as a result, the transmission distance can be extended.

Furthermore, in this embodiment, only the vicinity of the other end faces 20a, 21a of the movable fibers 20, 21 are fixed to the movable body 16, so the movable part can be made substantially smaller and lighter, and the optical path can be switched at high speed. It can also be done.

Furthermore, since this embodiment has both an optical switch function and a photoelectric conversion function, it can be easily downsized and highly reliable compared to the conventional examples shown in FIGS. 5 and 6. Note that the optical waveguide 17 is not limited to an optical fiber, and may be formed by, for example, a condensing lens.

Next, a second embodiment of the present invention will be described with reference to FIG. However, the same reference numerals as those in the first embodiment indicate the same parts, and no particular explanation will be given.

That is, in this embodiment, a U-shaped optical waveguide 17 is used, and the input end face 17a of the optical waveguide 17, the receiving face of the optical receiver 19, the output end 17b of the optical waveguide, and the transmitting face of the optical transmitter 18 are arranged on the same plane. Place the movable body 1 on top.
6 is a flat plate, and a light input port 12 and a light output port 13 are provided on one side of the housing.

According to this embodiment, the input movable optical fiber 20
Since the end faces of the movable output optical fibers 21 on the side of the movable body 17 are arranged in parallel, the structure of the movable body 16 is simplified and can be further miniaturized, and the operability of connecting the optical connector of the external transmission path is significantly improved. .

Next, a third embodiment of the present invention will be described with reference to FIG. However, the same reference numerals as those in the first embodiment indicate the same parts, and no particular explanation will be given.

That is, in this embodiment, the input movable optical fiber 20
It is characterized in that condensing lenses 27 and 28 are arranged on the end surface of the movable optical fiber 21 for output on the movable body 16 side. In this embodiment, any one of a condensing lens, an optical fiber, or a transparent material can be used for the optical waveguide 17, and at the same time, optical loss can be significantly reduced. It is also possible to use an air layer as the optical waveguide 17, and in this case, it is not necessary to separately provide the optical waveguide 17. Furthermore, the condensing lenses 27 and 28 may be used for at least one of them.

〔Effect of the invention〕

As described above, according to the present invention, it is possible to reduce the optical coupling loss between the external transmission line, the optical transmitter, and the optical receiver, so that the transmission distance can be extended. Furthermore, since the movable body housed in the housing can be made smaller and lighter, optical path switching can be performed at high speed. Furthermore, although it is an optical transmission device with an optical bypass mechanism that has both an optical switch function and a photoelectric conversion function, it can be made smaller and has improved reliability.

[Brief explanation of drawings]

1 and 2 are diagrams showing a first embodiment of the present invention, in which FIG. 1 is a perspective view, FIG. 2 is a schematic configuration diagram, and FIG. 3 is a diagram showing a second embodiment of the present invention. FIG. 4 is a schematic configuration diagram showing a third embodiment of the present invention, FIGS. 5 and 6 are diagrams showing a conventional system, and FIG. 5 shows a system operating as a station. FIG. 6 is an explanatory diagram showing the optical bypass state. 12... Light entrance port, 13... Input/exit port, 14... Housing, 15... Drive mechanism, 16...
Movable body, 17... optical waveguide, 18... optical transmitter,
19... Optical receiver, 20... Movable input fiber, 21... Movable output optical fiber, 27, 28
……Condenser lens.

Claims (1)

[Scope of Claims] 1. A housing provided with a light entrance port and a light exit port, and a housing provided within the housing and fixed near one end so that the optical axis coincides with the entrance port and the exit port, respectively. a movable optical fiber for input and a movable optical fiber for output, each of which is fixed to a movable body that is movable near the other end to a first position or a second position by a drive mechanism; an optical waveguide provided in the housing so as to be aligned with the optical axis of the movable body side end face of each of the movable input fiber and the movable output fiber at the position; A light comprising a light emitting element and a light receiving element provided in the housing so as to coincide with the optical axes of the movable body side end surfaces of the movable input fiber and the movable output fiber. Optical transmission device with bypass mechanism. 2. The optical transmission device with an optical bypass mechanism according to claim 1, wherein the optical waveguide is an optical fiber. 3. The optical transmission device with an optical bypass mechanism according to claim 1, wherein the optical waveguide is a condenser lens. 4. The optical bypass mechanism according to claim 1, characterized in that a condenser lens is provided on at least one of the movable body side end face of the movable input optical fiber and the movable body end face of the output movable optical fiber. Optical transmission equipment with.