JPH03129313A - Optical switch using bimorph piezoelectric element - Google Patents

Abstract

PURPOSE:To easily realize the 1:N optical switch by controlling the voltages applied to the bimorph piezoelectric elements and moving an optical fiber directly. CONSTITUTION:When the connection of an optical fiber 17 on a movable base 13 is switched from an optical fiber 152 on a fixed base 11 to an optical fiber 153, the voltages applied to the bimorph piezoelectric elements 21 and 25 are controlled and the movable base 13 is moved so that the optical axis of the optical fiber 17 is aligned with the optical axis of the optical fiber 153. Then electromagnetic actuators 551 and 552 are driven to insert pins 531 and 532 into holes 512 and 516 and the movable base 13 is fixed. In such a case, the bimorph piezoelectric elements are variable in deformation quantity with the applied voltage, and the base is moved through a plunger by controlling the applied voltages to perform 1:n switching between the optical fibers. Thus, the 1:n switching with low insertion loss is enabled by the simple constitution.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to an optical switch used for switching optical fiber transmission lines. In particular, the present invention relates to an optical switch that mechanically switches optical paths by movable optical fibers.

[Conventional technology]

Optical switch systems are divided into those using mechanical switching and those using non-mechanical switching. Non-mechanical switching is a configuration in which the optical path is switched by changing the refractive index of the medium using an electric field, magnetic field, or sound wave, causing refraction, reflection, interference, or a change in the polarization plane, and the switching speed is fast. It has high reliability and other features. However, it also has other problems such as high insertion loss, high connection loss with optical fiber, and high crosstalk.

Practical applications are therefore dominated by mechanical switching, which has slow switching speeds but low insertion loss and low crosstalk.

This mechanical switching optical switch is a mirror,
Although the prism and the optical fiber are movable, in order to minimize insertion loss, it is advantageous to have a structure in which the optical fiber is movable and designated optical fibers are opposed to each other.

Conventionally, a method using a computer-controlled robot has been proposed for the 1:n optical switch, which switches the optical path by moving an optical fiber (IEICE 70th Anniversary Conference, 1988, Nα2073).

The 1-to-n optical switch proposed here uses a robot hand to grasp an optical connector connected to an optical fiber, inserts the optical connector into a specified optical connector adapter under computer control, and switches the optical path. This is a configuration for making connections.

[Problem to be solved by the invention]

In such an optical switch, the control of the robot is complicated, and the structure of the optical switch itself is inevitably complicated and large-scale.

SUMMARY OF THE INVENTION An object of the present invention is to provide an optical switch that has a simple configuration, has low insertion loss, and can perform 1:n switching.

[Means to solve the problem]

An optical switch according to claim 1 includes: one base having a plurality of optical fibers installed side by side, and the other base having a single optical fiber having an optical axis parallel to the optical fibers facing each other; A bimorph piezoelectric element whose one end is fixed and which deforms in its thickness direction according to an applied voltage, and a plunger which is supported at the other end of the bimorph piezoelectric element and moves the one base or the other base according to the deformation. and a cough corresponding to the position where the applied voltage of the bimorph piezoelectric element is controlled and the optical axis of one of the zero optical fibers of the one stand and one optical fiber of the other stand is aligned. 1:n switching control means for determining the amount of movement of the stand and switching between 1 opposing optical fibers.

An optical switch according to claim 2 includes one stand on which a plurality of optical fibers are installed, and another stand on which one optical fiber whose optical axis is parallel to the optical fibers is installed facing each other, A plurality of elements that deform in the same direction depending on the applied voltage are stacked, one end of one of the elements is fixed, the ends of each element are alternately joined, and the other end is attached to one of the stands or A bimorph piezoelectric element that is moved by the applied voltage within the moving plane of the other table, and the voltage applied to the bimorph piezoelectric element is controlled, and one of the optical fibers of the one table is connected to the other table. 1:n switching control means for determining the amount of movement of the cough table corresponding to the position where the optical axis of the cough table coincides with one of the optical fibers, and switching between 1:n optical fibers.

An optical switch according to claim 3 includes an optical switch using the bimorph piezoelectric element according to claim 1 or claim 2, and a fixing means for fixing the mutual positions of one base and the other base, and an optical fiber. After switching, the fixing means is activated to fix the one base and the other base, and the voltage applied to the bimorph piezoelectric element is cut off, and before switching the optical fiber, the fixing means is activated to fix the one base and the other base. The device includes a switching holding control means for releasing the fixation of the base and the other base and applying a predetermined voltage to the bimorph piezoelectric element.

An optical switch according to claim 4 includes a plurality of N 1:n1 and 1:n2 optical switch according to any one of claims 1 to 3 arranged on the input side and a plurality M on the output side. , n,XN optical fibers of each optical switch on the input side, and n,XM of each optical switch on the output side (=n,
XN) optical fibers are fixedly wired according to a predetermined combination, and the voltage control means of each optical switch on the input side and output side is controlled in conjunction to switch the N to M optical fibers. It is configured to include a switching control means.

[For production]

The invention according to claim 1 provides a bimorph piezoelectric element in which a plurality of optical fibers and one optical fiber are respectively installed on a stand and faced to each other, and the amount of deformation (curvature) of the stand can be varied by applying a voltage. By controlling the applied voltage and moving the stand via the plunger, it is possible to switch the opposing optical fibers.

The invention according to claim 2 overlaps a plurality of bimorph piezoelectric elements that deform in the same direction in response to an applied voltage, and alternately joins their respective ends to overlap the amount of deformation in each bimorph piezoelectric element. It can be used to control the position of the stand.

According to the third aspect of the invention, after switching, the mutual positions of the units are fixed and the voltage applied to the bimorph piezoelectric element is controlled to be cut off, thereby maintaining the switching state without supplying power. Can be done.

The invention according to claim 4 has a plurality of N l-to-n optical switches arranged on the input side, a plurality M 1-to-n optical switches arranged on the output side, and H,XN (nzXM) optical switches arranged between them. By coupling with optical fibers and interlocking the optical switches on the input side and the output side, it is possible to switch between N to M optical fibers.

〔Example〕

Hereinafter, embodiments of the present invention will be described in detail based on the drawings.

FIG. 1 is a diagram showing the configuration of an embodiment of the 1-to-n switching section of the optical switch of the present invention. In this embodiment, a case where n=4 will be described.

In the figure, one of the two stands on which the optical fiber is installed is a fixed stand 11, and the other is a movable stand 13 supported by a guide 12. The fixed base 11 has four optical fibers 151~
15. are fixed with their optical axes parallel and their ends aligned. Each optical fiber 15. 1 with optical axis parallel to ~154 optical axes
A real optical fiber 17 is fixed.

Transmission of optical signals in this 1-to-4 switching section is carried out between the optical fiber 17 of the movable table 13 and the fixed table 1 that coincides with the tip axis of the optical fiber 17 of the movable table 13.
1 of optical fibers 15I to 154. That is, by moving the movable base 13 and selecting the optical fiber of the fixed base 11 that faces the optical fiber 17, it is possible to function as a 1:4 optical switch. Note that the fixed base 11 and the movable base 1 are arranged so that the opposing optical fibers are positioned extremely close to each other.
3 is placed.

In the present invention, the deformation of the bimorph piezoelectric element is used as a means for moving the movable base 13, and the amount of deformation is controlled by controlling the applied voltage, thereby enabling selection operation as an optical switch. That is, one end of the bimorph piezoelectric element 21 is fixed (FIG. 1 only shows a part of it, so the fixed end is not shown), and the other end is connected to the variable joint 22, which can be bent in the same direction as the bending direction of the bimorph piezoelectric element 21. Plunger 23 is connected. The plunger 23 is supported by a guide 24 in parallel with the movable metalwork 3 so that its end pushes the movable base 13 by the bending of the bimorph piezoelectric element 21. Note that when no voltage is applied, the bimorph piezoelectric element 21 is not deformed and lies on a straight line, and is perpendicular to the movable base 13 and the plunger 23 (shown by a broken line in FIG. 1).

Furthermore, in this embodiment, since the plunger 23 has a structure that only pushes the movable base 13, a similar bimorph piezoelectric element 25, a variable joint 26, a plunger 27, and a guide 28 are provided on the opposite side.

Note that when one plunger pushes, the other plunger is controlled to support it.

FIG. 2 is a diagram showing an embodiment of a bimorph piezoelectric element according to claim 2.

In the figure, a bimorph piezoelectric element 71 and a bimorph piezoelectric element 72 bend in the same direction depending on the applied voltage.
One end thereof is joined at a joining part 73. Similarly, the bimorph piezoelectric element 75 and the bimorph piezoelectric element 76 are joined at one end at a joining portion 77.

The other ends of the bimorph piezoelectric elements 7e and 75 are fixed, and the other ends of the bimorph piezoelectric elements 72 and 76 are in contact with the movable base 13, and the respective The amount of deformation is superimposed and the movable base 13
This configuration determines the amount of movement.

That is, each bimorph piezoelectric element 71.72.75.7
Reference numeral 6 has a configuration in which a zigzag shape is folded or unfolded depending on the applied voltage, and the movable base 13 is pushed with the tip opposite to the fixed end. Therefore, the ends of the bimorph piezoelectric elements 72 and 76 that contact the movable base I3 can be moved within the moving plane of the movable base 13 in substantially parallel to the moving direction thereof, so that the variable The joints 22, 26 and plungers 23, 27 can be made unnecessary.

Although this example shows a configuration using two bimorph piezoelectric elements, it is also possible to use more bimorph piezoelectric elements, and the longitudinal length of each bimorph piezoelectric element is equal to the number of bimorph piezoelectric elements. It can be made relatively short depending on the size of the optical switch, making it easy to downsize the entire optical switch.

FIG. 3 is a diagram showing the configuration of each embodiment of a bimorph piezoelectric element and a power supply control means for controlling the voltage applied thereto.

In the figure, the bimorph piezoelectric element has three electrodes 31.
It has a structure in which piezoelectric elements 35 and 36 polarized in the same direction are inserted between the outer electrodes 31 and 33.
3 and the intermediate electrode 32 is grounded. That is, the piezoelectric element 35 inserted between the electrodes 31 and 32 moves in the direction from the electrode 31 to the electrode 32, and the piezoelectric element 36 inserted between the electrodes 32 and 33 moves in the direction from the electrode 32 to the electrode 33. Since the electrodes 31 and 33 are polarized, applying a predetermined voltage to the electrodes 31 and 33
It has a structure that bends with the side facing inward.

-4, the microcomputer 41 converts control data corresponding to the position of the optical fiber to be selected into a DC voltage via a digital/analog converter (D/A) 42, and sends the control data to the voltage supply section 45 via a command line 43. Send to. The voltage supply unit 45 amplifies the DC voltage input via the command line 43 and supplies the amplified DC voltage to the electrodes 31 and 33 of the bimorph piezoelectric element via the power line 46, thereby amplifying the bimorph piezoelectric element according to the applied voltage. The curvature of is determined.

The bending index of the bimorph piezoelectric element determined according to the applied voltage directly corresponds to the amount of movement of the movable table 13 (optical fiber 17), and the curvature of the bimorph piezoelectric element directly corresponds to the amount of movement of the movable base 13 (optical fiber 17). Fibers are selected to implement optical switches.

Note that the voltage applied to each bimorph piezoelectric element 21.25 is
Each of them is independently controlled according to the predetermined relationship described above, and for example, corresponding voltage control units are provided to correspond to this.

Further, the voltage supply unit 45 here includes a transistor 47 and a resistor 48 . Although an example using an emitter follower circuit constituted by 483 is shown, other voltage amplification circuits may be used.

FIG. 4 is a diagram showing an example of the external configuration of a 1-to-4 optical switch.

In the figure, from the 1 to 4 switching unit (Fig. 1) 49,
Each optical fiber 15 on the fixed base 11. 154 and the optical fiber 17 of the movable table 13 are pulled out. Further, the voltage supply section 45 amplifies the control voltage input from the microcomputer 41 via the command line 43, and applies the control voltage to the bimorph piezoelectric element 21.25 in the 1-to-4 switching section 49 via the power line 46. Supplied as voltage.

As shown above, the bending index of the bimorph piezoelectric element 21.25 is determined by the control of the microcomputer 41, and as the movable table 13 moves accordingly, the optical fibers 151 to 154 facing the optical fiber 17 are is selected.

In addition, in order to apply a predetermined voltage to each of the bimorph piezoelectric elements 21 and 25 and maintain that state after the switching operation as an optical switch is completed, apply the voltage to the bimorph piezoelectric elements 2I and 25 as is ( However, movable platform 1
By providing a fixing means in 3, it is possible to eliminate the need for power supply to maintain the state after switching.

FIG. 1 also shows an embodiment of the fixing means (corresponding to claim 3) for the movable table 13 whose drive is controlled in conjunction with the control operation of the bimorph piezoelectric element 2125.

In the figure, on both sides of the optical fiber 17 of the movable table 13,
Each optical fiber 15 of the fixed base 11. Holes 51. to 15. ~51. On the other hand, the fixing base 1 has pins 53, . 53□ is provided. Bin 53. ．． 53□ is a bimorph piezoelectric element 21.2
The electromagnetic actuator 558.55 is connected to the electromagnetic actuator 558.55, which is driven in conjunction with the control operation of No.5.

That is, for example, the optical fiber 15.
When switching to the microcomputer 41, first
is connected to the electromagnetic actuator 55 through the voltage supply section 45. ．．
Drive 55z and pin 531.53! The hole 513.51
? Remove from.

Subsequently, the voltages applied to the bimorph piezoelectric elements 21 and 25 are controlled to move the movable table 13 to a position where the optical axes of the optical fibers 17 and 15 degrees coincide. Further on,
tm actuator 55. ．． 55□, and bin 53
1.532 into the holes 51□ and 51° to fix the movable base 13.

In this way, since the movable table 13 is fixed after switching, the state can be maintained even if the voltage applied to the bimorph piezoelectric elements 21, 25 is cut off. In addition, at that time, the bimorph piezoelectric elements 21 and 25 are on a straight line, and the plungers 23 and 27 are respectively separated from the movable base 13.

Furthermore, the same effect can be obtained even if a bimorph piezoelectric element having the configuration shown in FIG. and move away from the movable base 13.

Figure 5 shows a 4-to-4 optical switch constructed using a 1-to-4 optical switch.
It is a figure showing an example composition of an optical switch.

In the figure, on the input side, four 1-to-4 switching units 49 are stacked. ~494 to optical fiber 17 as input line
1 to 174 are pulled out, and on the output side, a 1 to 4 switching section 49. ~49. are rotated 90 degrees with respect to the input side and placed side by side, and an optical fiber 17. is connected as an output line. ~178 is drawn. The optical fiber 151 is drawn out from the 1-to-4 switching section 491 on the input side. -1514 are output-side 1-to-4 switching units 49s-49. are connected to each. Similarly, the 1-to-4 switching section 49 on the input side. 494, and a 1-to-4 switching section 49 on the output side. ~49g is fixedly connected by 15 layers of 16 non-intersecting optical fibers ~1544. Incidentally, FIG. 6 shows an outline of the wiring configuration of the 4-to-4 optical switch.

Further, a voltage supply section 45' is connected to the microcomputer 41 via a command line 43, and each power line 46. 1 to 4 switching units 491 to 498 are connected via terminals 468 to 468, respectively.

With this connection arrangement, the 1:4 optical switch on the input side selects one of the 4 1:4 optical switches on the output side for one input line, and selects one of the 1:4 optical switches on the output side for one input line. The switch is 1,
A 4-to-4 optical switch can be configured by selecting one of the four 1-to-4 optical switches at the input end for one output line. That is, for example, an optical fiber 17° on the input side and an optical fiber 17° on the output side. When connecting the optical fiber 17° and the optical fiber 1514 with the 1-to-4 switching section 491, the 1-to-4 switching section 4
9. Optical fiber 17. Switching control is performed in conjunction to connect the optical fiber 1514 and the optical fiber 1514.

As shown in FIG. 6, the method of combining 1:4 switches to form a 4:4 switch and its switching method are already known, but the present invention incorporates a bimorph piezoelectric element in each switch section. It is characterized by the use of an optical switch using

Further, in the embodiments described above, 1:4 and 4:4 optical switches are shown, but 1:N and N:M optical switches can be similarly realized by the method of the present invention. Note that an N to M optical switch has 1 to n1 on the input side.
N optical switches of 1 to n2 are arranged on the output side, and n IX N (-n z
It can be constructed by coupling X M ) optical fibers and interlocking optical switches on the input side and the output side.

〔Effect of the invention〕

As described above, the optical switch according to the present invention has a structure in which the optical fiber is directly moved by controlling the applied voltage to the bimorph piezoelectric element, so that the connection thereof can be arbitrarily switched. Furthermore, it has low insertion loss, can be made smaller and lighter, and can be used in 1:N or N:M
The optical switch can be easily realized.

In particular, in the invention described in claim 2, by combining a plurality of bimorph piezoelectric elements, the length in the longitudinal direction of the bimorph piezoelectric element corresponding to the amount of movement of the optical fiber can be relatively shortened. The entire structure can be further downsized.

Further, in the invention as set forth in claim 3, it becomes easy to maintain the switching position of the optical switch, and it becomes possible to improve reliability and reduce power consumption.

Further, according to the invention as set forth in claim 4, by interlocking each optical switch on the input end and the output side, it is possible to easily realize an N to M optical switch.

[Brief explanation of the drawing]

FIG. 1 is a diagram showing the configuration of an embodiment of the 1-to-n switching section of the optical switch of the present invention. FIG. 2 is a diagram showing an embodiment of a bimorph piezoelectric element according to claim 2. FIG. 3 is a diagram showing the configuration of each embodiment of a bimorph piezoelectric element and a power supply control means for controlling the voltage applied thereto. FIG. 4 is a diagram showing an example of the external configuration of a 1-to-4 optical switch. FIG. 5 is a diagram showing an embodiment of a 4-to-4 optical switch constructed using a 1-to-4 optical switch. FIG. 6 is a diagram schematically showing the wiring configuration of a 4-to-4 optical switch. 11... Fixed stand, 12.24.28... Guide, 1
3...Movable table, 1.5.17...Optical fiber, 21
．． 25... Bimorph piezoelectric element, 22.26... Variable joint, 23.27... Plunger, 31-33...
・Electrode, 35. 36... Piezoelectric element, 41... Microcomputer, 43... Command line, 45...
・Voltage supply section, 46...power line, 49...1
Pair 4 switching unit, 51... Hole, 53... Bin, 55
...Electromagnetic actuator, 71.72.75.76.
... Bimorph piezoelectric element, 73.77... Junction. Figure 3 Figure Figure Figure [)-Series] 7 17゜17゜17゜+7s 17゜17゜17゜ [Output] Figure

Claims (4)

[Claims] (1) One table has a plurality of n optical fibers installed, and the other table has one optical fiber with its optical axis parallel to the optical fiber installed facing each other, one end of which is fixed, and an applied voltage is applied. a bimorph piezoelectric element that deforms in its thickness direction according to the deformation of the bimorph piezoelectric element; a plunger that is supported at the other end of the bimorph piezoelectric element and that interlocks the one base or the other base according to the deformation of the bimorph piezoelectric element; The applied voltage is controlled to determine the amount of movement of the table corresponding to the position where the optical axes of one of the n optical fibers of the one table and one optical fiber of the other table are aligned. , and 1:n switching control means for switching 1:n optical fibers. An optical switch using a bimorph piezoelectric element. (2) One table with a plurality of n optical fibers installed and the other table with a single optical fiber whose optical axis is parallel to the optical fiber installed facing each other in the same direction depending on the applied voltage. A plurality of elements that can be deformed are piled up, one end of one of the elements is fixed, the ends of each element are alternately joined, and the other end is connected to the moving surface of the one table or the other table. a bimorph piezoelectric element that moves according to the applied voltage within the device, and a bimorph piezoelectric element that controls the applied voltage of the bimorph piezoelectric element, and connects one of the n optical fibers of the one stand and one optical fiber of the other stand. A bimorph piezoelectric element is used, characterized in that it is equipped with a 1:n switching control means that determines the amount of movement of the table corresponding to the position where the optical axes of light switch. (3) In the optical switch using the bimorph piezoelectric element according to claim 1 or claim 2, a fixing means for fixing the relative positions of one base and the other base, and activating the fixing means after switching the optical fiber. to fix the one stand and the other stand, cut off the voltage applied to the bimorph piezoelectric element, and activate the fixing means before switching the optical fiber to fix the one stand and the other stand. What is claimed is: 1. An optical switch using a bimorph piezoelectric element, characterized in that it is provided with a switching holding control means for releasing the voltage and applying a predetermined applied voltage to the bimorph piezoelectric element. (4) A plurality of N 1-pair n_1 and 1-pair n_2 optical switches according to any one of claims 1 to 3 are arranged on the input side and a plurality M on the output side, and each optical switch on the input side The n_1×N optical fibers of the optical switch on the input side and the n_2×M (=n_1×N) optical fibers of each optical switch on the output side are fixedly wired according to a predetermined combination, and each optical switch on the input side and the output side The voltage control means of N are controlled in conjunction with each other to switch between N and M optical fibers.
An optical switch using a bimorph piezoelectric element, characterized in that it is equipped with a pair of M switching control means.