JPH095651A - Filter moving type optical switch - Google Patents

Abstract

PURPOSE: To make it possible to reduce the size of the above switch, to substantially prevent the occurrence of the misalignment of an optical axis and to enhance reliability by putting an optical filter into and out between the end faces of optical fibers. CONSTITUTION: The one end side of a movable body 29 is attracted toward one of permanent magnets 33a, 33b (or magnetic materials magnetized by these permanent magnets) in the state that the optical filter emerges outside between the end faces of the optical fibers 25a, 25b. The movable body 29 is so magnetized that the moving body repulses against the one permanent magnet and attracts the other permanent magnet each other by passing current to a coil 35. The movable body 29 is then moved toward the other permanent magnet. The optical filter 27 is then held introduced between the end faces of the optical fibers 25a, 25b. The movable body 29 moves toward the one permanent magnet side when the movable body 29 is magnetized by passing backward current to the coil 35 in such a manner that the movable body 29 repulses against the other permanent magnet and attracts the other permanent magnet each other. The optical filter 27 is put into and out between the end faces of the optical fibers 25a and 25b in such a manner, by which the switching of light signals is executed.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an optical switch using an optical filter.

[0002]

2. Description of the Related Art An optical switch using a conventional optical filter is shown in FIGS. In the figure, reference numeral 11 is an inlet side connector, 13 is an outlet side connector, 15a is a moving side connector for switching an optical path, 15b is a fixed side connector for switching an optical path, 17 is an optical filter, and 19a and 19b are optical fibers for this optical path. , 21a and 21b are optical fibers for bypass optical path, and 23 is a case.

When the moving side connector 15a is in the position shown in FIG. 5, the optical fibers 19a and 19b for the optical path are connected, and an optical signal is transmitted from the inlet side connector 11 to the outlet side connector 1.
3 is directly transmitted. On the other hand, the moving side connector 15a
Is in the position shown in FIG. 6, the optical fiber 19a for this optical path is
And the bypass optical path optical fiber 21a are connected to the main optical path optical fiber 19b and the bypass optical path optical fiber 21b, respectively, and the optical signal entering from the inlet side connector 11 is transmitted to the outlet side connector 13 through the optical filter 17. It That is, this optical switch switches between the state of FIG. 5 in which the optical signal is transmitted as it is and the state of FIG. 6 in which only the optical signal passing through the optical filter 17 is transmitted.

[0004]

The conventional optical switch has the following problems. That is, since the connector for switching the optical path is used, the deviation of the optical axis is likely to occur in this portion, and it is difficult to repeatedly reproduce the low loss connection. Further, since the bypass optical path is provided separately from the main optical path and the optical filter is installed in the bypass optical path, there is a drawback that a large component storage space is required and the optical switch becomes large.

In view of the above-mentioned problems, an object of the present invention is small, highly resistant to optical axis misalignment, and highly reliable.
An object of the present invention is to provide a filter moving type optical switch.

[0006]

The optical switch of the present invention comprises:
A thin plate-shaped optical filter is inserted into and removed from an end face of an optical fiber installed so that the optical axes are aligned to switch an optical signal, and a movable body made of a magnetic material that supports the optical filter and the movable body A guide that guides the body in the moving direction of the optical filter, a coil that magnetizes the movable body in the moving direction of the optical filter, and a permanent magnet or the same magnetic pole installed so that the same magnetic poles face each other at both ends of the guide face each other. As described above, a magnetic body installed in a state magnetized by a permanent magnet is provided.

[0007]

The optical switch operates as follows. In a state where the optical filter is exposed outside between the end faces of the optical fiber, one end side of the movable body is attracted to one permanent magnet (or a magnetic body magnetized by the permanent magnet). This state is self-maintained even when no current is flowing through the coil. In this state, an electric current is applied to the coil to magnetize the movable body so as to repel the one permanent magnet and attract the other permanent magnet. Then, the movable body moves toward the other permanent magnet and sticks to the other permanent magnet. With this, the optical filter is placed between the end faces of the optical fiber. In this state, since the movable body is attracted to the other permanent magnet, it is self-held even if the coil current is cut off. Next, a current in the opposite direction to the above is applied to the coil to magnetize the movable body so as to repel the other permanent magnet and attract the one permanent magnet. Then, the movable body moves to one permanent magnet side and is attracted to one permanent magnet. With this, the optical filter is brought out (between) between the end faces of the optical fiber. This state is self-maintained even when the coil current is cut off.

In this optical switch, an optical filter is inserted / removed between the end faces of the optical fiber as described above to switch the optical signal. The state in which the optical filter extends from between the end faces of the optical fiber and the state in which the optical filter enters between the end faces of the optical fiber are self-held by the movable body being attracted to one of the permanent magnets.

[0009]

【Example】

[Embodiment 1] FIG. 1 shows an embodiment of the present invention. In the figure, reference numerals 25a and 25b denote optical fibers installed with their optical axes aligned with each other with a gap between the end faces, and 27 denotes an optical fiber 25a,
It is a thin plate-shaped optical filter that is inserted and removed between the end faces of 25b.

The optical filter 27 is supported by a movable body 29 made of a magnetic material (iron rod or the like). The movable body 29 is housed in a cylindrical guide 31 made of a non-magnetic material (aluminum or the like), and the optical filter 27 has optical fibers 25a and 25b.
It is possible to move in and out between the end faces. Permanent magnets 33a and 33b are fixed to both ends of the guide 31 with the same magnetic poles facing each other (N poles facing each other in the illustrated example). A coil 35 that magnetizes the movable body 29 in the moving direction is wound around the outer circumference of the guide 31.

Next, the operation of this optical switch will be described with reference to FIG.
An explanation will be given with reference to (f). First, the state in which no current flows in the coil 35 as in (a) is set as the initial state. In this state, the movable body 29 sticks to the first permanent magnet 33a, and the optical filter 27 is exposed outside the end faces of the optical fibers 25a and 25b. Therefore, the optical signal is the optical fiber 2
5a to 25b (or vice versa). This state is self-maintained by the magnetic force of the first permanent magnet 33a even if no current flows in the coil 35.

In this state, when a current is passed through the coil 35 as shown in (b), the movable body 29 is magnetized so that the left end is the N pole and the right end is the S pole. Therefore, the movable body 29 is connected to the first permanent magnet 33a.
Repulsing each other, attracting each other with the second permanent magnet 33b,
It moves to the right and is attracted to the second permanent magnet 33b as shown in (c). In this state, the coil 35
Even if the current applied to the second permanent magnet 33b is stopped, it is self-held by the magnetic force of the second permanent magnet 33b. In this state, the optical filter 27 enters between the end faces of the optical fibers 25a and 25b, so that the optical signal is transmitted from the optical fibers 25a to 25b through the optical filter 27. That is, the optical signal that cannot pass through the optical filter 27 is cut here.

Next, in this state, the coil 35 as shown in FIG.
When a current is applied in the direction opposite to the front, the movable body 29 is magnetized so that the right end is the N pole and the left end is the S pole. Therefore, the movable body 29 repels the second permanent magnet 33b, and the first permanent magnet 3
3a is attracted to each other, moves to the left, and is attracted to the first permanent magnet 33a as shown in (f). In this state,
Since the optical filter 27 goes out between the end faces of the optical fibers 25a and 25b, the optical signal is transmitted from the optical fibers 25a to 25b.
Is transmitted as is. When the current flowing through the coil 35 is stopped in this state, the state returns to (a).

In this optical switch, the optical filter 27 is inserted and removed between the end faces of the optical fibers 25a and 25b as described above to switch the optical signal. The switching can be performed by passing a current through the coil 35 for a short time. Although the two permanent magnets are installed with the N poles facing each other in the above embodiment, they may be installed with the S poles facing each other.

In order to prevent reflection on the end face of the optical fiber, a refractive index matching agent such as silicon oil may be inserted between the end faces of the optical fiber. Further, by immersing not only between the end faces of the optical fiber but also the region where the optical filter moves in the index matching agent, the optical filter can be protected from the shock generated when the optical filter moves. Further, in order to prevent reflection at the end faces of the optical fibers, the end faces of the optical fibers may be abutted at a slight angle with respect to the optical axis of each optical fiber.

[Embodiment 2] FIG. 3 shows another embodiment of the present invention. This optical switch differs from the optical switch of the first embodiment in that magnetic bodies 37 magnetized to the same polarity by permanent magnets 33 are installed at both ends of the guide 31. Since the other configurations are the same as those of the optical switch of the first embodiment, the same parts as those in FIG. 4A to 4F show the operation of the optical switch shown in FIG. 4A to 4F correspond to FIGS. 2A to 2F, respectively. That is, since the operation of this optical switch is the same as the operation of the optical switch of the first embodiment, the description is omitted.

[0017]

Since the optical switch of the present invention is a system in which an optical filter is inserted and removed between the end faces of the optical fiber, a conventional optical path switching connector is not required and the optical axis is displaced. There is no. Further, it is not necessary to provide a bypass optical path, and the optical filter is moved by a permanent magnet and a coil, so that the entire size can be reduced. Furthermore, since the state where the optical filter is located between the end faces of the optical fiber and the state where the optical filter is located between the end faces is self-held by the magnetic force of the permanent magnet, the operation does not become unstable even during a power failure. Further, since power supply to the coil only needs to be performed for a short time at the time of switching, power consumption can be reduced.

[Brief description of drawings]

FIG. 1 is a perspective view showing an embodiment of an optical switch according to the present invention.

2A to 2F are explanatory views showing the operation of the optical switch of FIG.

FIG. 3 is a plan view showing another embodiment of the optical switch according to the present invention.

4A to 4F are explanatory views showing the operation of the optical switch of FIG.

FIG. 5 is a plan view showing a state in which an optical filter of a conventional optical switch is not in an optical path.

6 is a plan view of the optical switch of FIG. 5 showing a state where an optical filter is in an optical path.

[Explanation of symbols]

 25a, 25b: Optical fiber 27: Optical filter 29: Movable body 31: Guide 33, 33a, 33b: Permanent magnet 35: Coil 37: Magnetic body

 ─────────────────────────────────────────────────── ─── Continued Front Page (72) Inventor Nobuo Tomita 1-1-6 Uchisaiwaicho, Chiyoda-ku, Tokyo Nihon Telegraph and Telephone Corporation

Claims (1)

[Claims] 1. An optical switch for switching an optical signal by inserting / removing a thin plate-shaped optical filter between end faces of an optical fiber installed in alignment with an optical axis, the optical switch comprising a magnetic material supporting the optical filter. A movable body, a guide that guides the movable body in the moving direction of the optical filter, a coil that magnetizes the movable body in the moving direction of the optical filter, and a permanent magnet installed so that the same magnetic poles face both ends of the guide. A filter moving type optical switch, comprising: a magnet or a magnetic body installed in a state of being magnetized by a permanent magnet so that the same magnetic poles face each other.