JP2842695B2 - Light switch - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to optical fiber communication and the like, in which a first switch element and a second switch element are relatively moved in the direction in which optical fibers are arranged, so that arbitrary optical fibers can be connected to each other. The present invention relates to an optical switch for selectively switching an optical coupling position so as to optically couple.

[0002]

2. Description of the Related Art Conventionally, an optical switch of this type is shown in FIG. In this device, a movable switch element 53 to which the other optical fiber 51 is fixed is moved by an electromagnetic solenoid or the like in a direction indicated by an arrow in the drawing with respect to a fixed switch element 52 to which one optical fiber 51 is fixed. Then, the optical path is switched. The butted end face of the fixed switch element 52 and the butted end face of the movable switch element 53 are respectively flat, and both end faces face each other in parallel with a small gap. The end face of the arrayed optical fiber 51 fixed to the end face of the arrayed optical fiber 51 fixed to the end face of the mobile switch element 53 is:
It is a face-to-face state with a minute gap. A pair of positioning pins 54, 54 penetrating the fixed and movable switch elements 52, 53 in the optical axis direction are attached to the switch elements 52, 53. For each of the positioning pins 54, the movable switch element 53 is formed. The optical path is switched by using the long groove 55 as a guide in the direction of the arrow in FIG.

In such a case, generally, the optical fiber 5 is placed between the end faces of the two optical fibers 51 in the array.
The entire optical switch is immersed in the refractive index matching agent S so as to fill the refractive index matching agent having substantially the same refractive index as that of No. 1 so as to reduce light loss and reflection from between the two optical fibers 51 and 51 end faces. I have to.

[0004]

When the optical switch having such a conventional structure is switched, the turbulent flow or pressure generated by the movement of the movable switch element 53 when the movable switch element 53 moves in the refractive index matching agent S. The change causes a cavitation or aeration phenomenon, and the refractive index matching agent S itself is vaporized. Alternatively, bubbles are generated by the precipitation of dissolved air in the refractive index matching agent S. In such a case, if the generated air bubbles enter between the end faces of the optical fiber 51, there is a problem that communication light is scattered and communication is temporarily interrupted. Specifically, as shown by comparing the normal communication light power in FIG. 8A with the communication light power due to the intrusion of bubbles in FIG. 8B, the communication light immediately after the switching operation is in an abnormal state. Was observed.

An object of the present invention is to provide an optical switch for preventing bubbles generated between end faces of an optical fiber from entering.

[0006]

In order to achieve the above object, the present invention provides a first switch element to which one end of an optical fiber array is fixed, and a second switch element to which another end of an optical fiber array is fixed. And a first switch in a state in which both optical fiber arrays face each other at their end faces, and a refractive index matching agent is filled between the end faces of the first and second switch elements. An optical switch for selectively switching an optical coupling position so as to optically couple arbitrary optical fibers by relatively moving the element and the second switch element in a direction in which the optical fibers are arranged; Second
And the end face of the first switch element and the end face of the first switch element so that the gap width between the fixation areas where the optical fiber arrays are fixed on the end faces of the two switch elements exceeds the gap width between the end faces of the other optical fiber arrays. The fixing region of at least one end face with the end face of the second switch element is recessed.

In this case, it is preferable that the fixing region is formed so that the gap width between the fixing regions of the first and second switch elements is 10 μm or more.

[0008]

With one of the first and second switch elements fixed, the other switch element is switched and moved to switch the optical path. In this case, a refractive index matching agent for reducing insertion loss is filled between the end face of the first switch element and the end face of the second switch element, and the refractive index generated by the switching operation of the switch element. Bubbles in the matching agent tend to move to a wider space side in the refractive matching agent due to surface tension. That is, since the gap width between the fixed regions of the first and second switch elements exceeds the gap width between the end faces of the other two optical fiber arrays, bubbles enter between the end faces of the optical fibers. Even in this case, the optical fiber moves to the side of the fixing region having a wider space, and does not enter between the end faces of the optical fiber.

[0009]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A communication optical switch according to an embodiment of the present invention will be described below with reference to the accompanying drawings with reference to FIGS. FIG. 1 is a perspective view showing an optical switch element of the optical switch according to the first embodiment, FIG. 2 is an enlarged perspective view of a main part thereof, and FIG. FIG. 3B is an enlarged plan view, and FIG. 3B is a vertical sectional side view of a main part of the optical switch element.

As shown in FIG. 1, in an optical switch device 1 constituting an optical switch, fixed switch devices 3 and 3 are disposed on both sides of a movable switch device 2 and both fixed switch devices 3 and 3 are mounted on a base ( (Not shown), a pair of positioning pins 4, 4 in the shape of a round bar fixed to the upper side and penetrated by both switch elements 2, 3.
Thus, the switching operation is performed with the movable switch element 2 suspended in the air. This switching operation mechanically moves the movable switch element 2 relative to the fixed switch element 3 between a steady position and one or more switch positions, and each time the optical fibers 5 of the two switch elements 2 and 3 are moved. The optical axes of A plurality of optical fibers 5 constituting a fiber array 6 are fixed to both butted end faces of the mobile switch element 2 and the fixed switch element 3, respectively.
The optical fibers 5 are aligned on the same optical axis and face each other by making the two switching elements 2 and 3 abut each other with the positioning pins 4 and 4 serving as a guide, thereby making an optical connection.

The moving switch element 2 includes a chip 7, a sheet plate 8 for holding the positioning pins 4, and a clamper 9 serving as a casing and biasing means. On both sides of the upper surface of the chip 7, a pair of positioning grooves 10a and 10b extending in parallel with the optical axis direction are formed. The pair of positioning grooves 10a, 10b
Is a first positioning groove 10a which engages with the positioning pin 4 at a steady position, and a second positioning groove 10b which engages with the switching position.
The positioning pin 4 can be clicked and relatively moved between the first positioning groove 10a and the second positioning groove 10b when a switch operation of the movable switch element 2 is performed. Each of the positioning grooves 10a and 10b is formed in a “V” shape (a “W” shape as a whole), and the round bar-shaped positioning pin 4 is provided in each of the positioning grooves 10a and 10b.
Contact is made at a point and the switching position of the optical path is restricted in a click-like manner, so that positioning for optical axis alignment is made accurate.

The seat plate 8 has two positioning pins 4,
4 are pressed uniformly, and the sheet plate 8 and the positioning pins 4 are simply in contact with each other without being bonded. This contact state is maintained by a clamper 9, which is made of stainless steel. The positioning pin 4 is inserted into the positioning groove 10 through the sheet plate 8.
a, 10b. With this bias,
Each positioning pin 4 comes into contact with each of the positioning grooves 10a and 10b at two points to ensure the alignment.

On the other hand, a predetermined number of fiber fixing grooves 11 are formed at the center of the upper surface of the movable chip 7 at the center in the optical axis direction, and the predetermined number of optical fibers 5 from which the coating is removed is engaged with the grooves. Have been. The predetermined number of the optical fibers 5 is provided with an adhesive 13
(See FIG. 3B) to form an optical fiber array 6 in which the end faces of the optical fibers 5 are aligned side by side.

For the purpose of reducing the insertion loss and reflection of communication light, an optical fiber between the end faces of the two optical fibers 5 is filled with a refractive index matching agent S having substantially the same refractive index as the optical fiber 5. The entire switch is immersed in the refractive index matching agent S.

In addition to the general configuration as described above, this embodiment, as shown in FIGS.
It has a unique configuration around a.

That is, both fixed and movable switch elements 2,
The fixing areas 21a, 21a to which the optical fibers are fixed are formed in the end faces 21, 21 of the third optical fiber 3, and the gap width between the butted areas 21a, 21a is equal to the width of the butted optical fibers. The width is larger than the gap width between the end faces 22. Therefore, in the fixing region 21a,
The optical fiber 5 slightly protrudes from the end faces of the switch elements 2 and 3 and is immersed in the refractive index matching agent S. In this case, as shown in FIG. 4, even if bubbles B are generated in the refractive index matching agent S by the switching operation of the moving switch elements 2 and 3, the bubbles B move to a wide space side due to the influence of the surface tension. Therefore, when an attempt is made to enter the gap between the end faces 22, 22 of the optical fibers 5, 5 as indicated by the arrow in FIG. It rises so as to wrap around the fiber 5. In this case, the fixing regions 21a, 21a of the first and second switch elements 2, 3 are fixed.
It is useful that the fixing regions 21a, 21a are recessed so that the gap width between 1a is 5 μm or more.

As shown in FIG. 1, the fixed switch element 3 and the mobile switch element 2 in front of the paper are separated from each other, and the fixed switch element 3 and the mobile switch element 2 in the front of the paper are separated from each other. Although they are in contact with each other, the positional relationship between the fixed switch elements 3 and 3 and the movable switch element 2 is actually the end face 2 of each of the optical fibers 5 and 5 facing each other.
2 and 22 are opposed to each other with a small gap in a range where they are not in contact with each other and are not damaged and a connection loss is small (the same applies to FIGS. 3 and 4). In this embodiment, the fixed switch elements 3 and 3 are disposed on both sides of the movable switch element 2 in the front-rear direction, so that the movable and fixed chips 2 and 3 are also positioned in the optical axis direction. The fixed switch element 3 has exactly the same configuration as the mobile switch element 2. However, the positioning pins 4 are bonded to the positioning grooves 10a and 10b and the sheet plate 8,
The positioning pin 4 is fixed to the fixed switch element 3. Further, the clamper 9 and the like of the fixed switch element 3 only function as a mere casing.

Next, the switching operation of the optical path of the optical switch element 1 will be described with reference to FIG.

FIG. 5A shows a steady state in which the mobile switch element 2 is at the steady position. The positioning pins 4 are sandwiched between the sheet plate 8 and the first positioning grooves 10a.
It is positioned by engaging with the positioning groove 10a. At this time, the predetermined optical fiber 5 of the fixed switch element 3 and the predetermined optical fiber 5 of the mobile switch element 2 face each other via a minute gap, and the optical connection is established.

FIG. 5B shows a neutral state in which the moving switch element 2 is in the middle of shifting from the steady position to the switching position. When a force is applied to the movable switch element 2 in the stationary position by a moving device (not shown), the movable switch element 2 is moved, and the gap between the sheet plate 8 and the chip 7 is moved by the positioning pin 4 to bias the clamper 9. The positioning pin 4 is dropped from the first positioning groove 10a into the second positioning groove 10b.

FIG. 5C shows a switching state in which the movable switch element 2 is at the switching position. Also in this case, the positioning pins 4 are engaged with the second positioning grooves 10b by the clampers 9 to perform positioning. At this time, the predetermined optical fiber 5 of the fixed switch element 3 and the predetermined optical fiber 5 of the mobile switch element 2 to be switched face each other via a minute gap, and the switching of the optical path is completed.

If this operation is performed in the reverse order, the switch is switched from the switching position to the steady position.

In this embodiment, the tip 7 is made of silicon, and the positioning pin 4 is a round bar made of zirconia having a diameter of 0.5 mm. Fiber fixing groove 12 and both positioning grooves 1
0a and 10b are produced by a V-groove grinding machine.
Then, in order to arrange six optical fibers 5 at a pitch of 0.25 mm, the fiber fixing grooves 12 are formed at a pitch of 0.25 mm.
Rows were formed, and the groove angle was 60 degrees. First positioning groove 10
a and the second positioning groove 10b had a pitch of 0.5 mm, and the groove angle was 110 degrees. In addition, both positioning grooves 10a, 1
The height over the positioning pin 4 between 0b was 0.1 mm. Further, the gap width between the fixing regions 21a, 21a is 1
The projecting length of each optical fiber 5 was set to 0.1 mm so as to be 0 μm or more.

Here, based on the optical switch prototyped under the above conditions, the fluctuation of the waveform of the communication light power and the insertion loss in 10,000 continuous switching operations were evaluated. In this case, the optical fiber 5 was a single mode fiber having a core diameter of 10 μm. Then, when 10 optical switches were evaluated, all of them were evaluated as shown in FIG.
The waveform was as shown in FIG. 8A, and no abnormal waveform as shown in FIG. Also, as shown in FIG. 6, the variation of the insertion loss is such that both the # 2 optical fiber 5 of the mobile switch element 2 and the # 1 optical fiber 5 of the fixed switch element 3
In both cases, the insertion loss had a fluctuation range of about 0.1 dB or less, and good results without the influence of bubbles could be obtained.

As described above, according to the present embodiment, the fixing areas 21a, 21a to which the optical fiber 5 is fixed are formed in the end faces 21, 21 of the fixed and movable switch elements 2, 3 in a recessed manner. The gap width between the two regions 21a, 21a is
Since the width exceeds the gap width between the end faces 22, 22 of the butted optical fibers 5, 5, the generated bubbles B in the index matching agent S are generated by the end faces 2 of the optical fibers 5, 5.
There is no intrusion into the gap between the second and the second 22, and there is no influence such as scattering on the communication light.

[0026]

As described above, according to the present invention, of at least one of the end face of the first switch element and the second switch element, the fixed area to which the optical fiber array is fixed is the first area. Since the gap width between the fixed regions of the second and the second switch elements is formed so as to exceed the gap width between the end faces of the two other optical fiber arrays, the one and the other two optical fiber arrays are formed. Air bubbles can be prevented from entering between the end faces of the light emitting device, and the optical path can be switched stably.

[Brief description of the drawings]

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

FIG. 2 is an enlarged perspective view of a main part of the optical switch element.

FIG. 3 is an explanatory view showing a structure of a butted portion of both optical switch elements.

FIG. 4 is an enlarged perspective view showing a state of abutting portions of both optical fibers.

FIG. 5 is a front view showing the operation of the optical switch.

FIG. 6 is an explanatory diagram of an experimental result.

FIG. 7 is a perspective view of a conventional optical switch.

FIG. 8 is a diagram showing experimental results for explaining a problem.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Optical switch element, 2 ... Moving switch element, 3 ... Fixed switch element, 5 ... Optical fiber, 6 ... Fiber array,
7: chip, 21: end face, 21a: fixed area, 22: end face, S: refractive index matching agent, B: bubble

──────────────────────────────────────────────────続 き Continuing from the front page (72) Inventor Seiichi Mobara 1st Tayacho, Sakae-ku, Yokohama-shi, Kanagawa Prefecture Sumitomo Electric Industries, Ltd. Yokohama Works (72) Inventor Toshiaki Kakii 1st Tayacho, Sakae-ku, Yokohama-shi, Kanagawa Sumitomo Electric (72) Inventor Hiroo Kanamori 1st place, Tayacho, Sakae-ku, Yokohama-shi, Kanagawa Prefecture Sumitomo Electric Industries, Ltd.Yokohama Works (72) Inventor Kazuhiko Arimoto 7-6-1, Omorinishi, Ota-ku, Tokyo Sumiden Opcom Co., Ltd. (58) Field surveyed (Int. Cl. ⁶ , DB name) G02B 26/08

Claims (2)

(57) [Claims] 1. An optical fiber array comprising: a first switch element to which an end of one optical fiber array is fixed; and a second switch element to which an end of another optical fiber array is fixed. Are opposed to each other, and the first switch element and the second switch element are connected to each other with the refractive index matching agent being filled between the end faces of the first and second switch elements. In an optical switch for selectively switching an optical coupling position so as to optically couple arbitrary optical fibers by relatively moving in an arrangement direction of the fibers, an optical fiber on an end face of the first and second switch elements An end face of the first switch element and the second end face of the second switching element are arranged such that a gap width between the fixed areas to which the array is fixed exceeds the gap width between the end faces of the one and the other optical fiber arrays.
An optical switch characterized in that a fixing region of at least one end face with an end face of the switch element is recessed. 2. The fixing region according to claim 1, wherein the fixing region is recessed such that a gap width between the fixing regions of the first and second switch elements is 10 μm or more.
An optical switch as described.