JP3527744B2 - Waveguide type optical switch - Google Patents

Description

Detailed Description of the Invention

[0001] [Detailed Description of the Invention]

TECHNICAL FIELD OF THE INVENTION

The present invention relates to a waveguide type optical switch used in the field of optical communication, and more particularly to a waveguide type optical switch which is small and suitable for remote operation.

[0002]

2. Description of the Related Art In order to further popularize optical communication, in addition to high performance and low cost of optical fibers and light emitting / receiving elements, various optical circuits such as optical branching / coupling circuits, optical multiplexing / demultiplexing circuits, optical switches, etc. Development of parts is essential. In particular, optical switches are considered to play an important role in the near future in order to switch optical fiber lines according to demand and to secure detours in case of line failure. As a form of optical switch,
There are proposed (1) bulk type, (2) optical fiber movable type, and (3) optical waveguide type. The bulk type is assembled by using a movable prism, a lens, and the like as constituent elements, and has an advantage that it has relatively low loss without wavelength dependence. The movable optical fiber type has a merit that the optical fiber itself is moved by a small actuator to select the optical fiber of the output destination, and the loss is relatively low. However, these types of optical switches have not been widely used because the assembly and adjustment process is complicated, they are not suitable for mass production, and they are expensive. The optical waveguide type is based on an optical waveguide on a flat substrate and is intended to mass-produce a so-called integrated type optical switch by using photolithography and microfabrication technology, and is expected as a future type optical switch. . As an optical waveguide type switch of this type, there is an optical switch disclosed in JP-A-6-148536. This switch is a 1 × 2 optical switch that switches optical paths by moving an optical waveguide formed on a cantilever using electrostatic force.

[0003]

[Problems to be Solved by the Invention]

The conventional optical switch described above has the following problems. That is, because the electrostatic force is used,
Since the drive voltage is as high as several tens of volts or more and the structure is a single cantilever beam, the tip of the waveguide rotates simultaneously with translation along with the light switching operation, and the light emitting surface and the incident surface of the waveguide are mutually There was a problem that they were not parallel and insertion loss increased. The present invention is to solve such problems,
It is an object of the present invention to provide a low-cost optical waveguide switch that can be driven at a low voltage of 10 volts or less and has a small insertion loss.

[0004]

[Means for Solving the Problems]

In order to achieve the above-mentioned object, the optical waveguide switch of the present invention is formed on a silicon substrate with a plurality of cantilevers that are parallel to each other and connected by a connecting member, and at least one cantilever. A first optical waveguide, and the plurality of cantilevers facing the first optical waveguide are deformed in a first direction or a second direction opposite thereto, and the first cantilever is formed on the cantilever; A plurality of second optical waveguides formed on the substrate to be optically coupled to the optical waveguides and switch driving means for deforming the cantilever, and the optical path is switched by deforming the cantilever. Is to do. Further, the optical switch of the present invention comprises a plurality of cantilevers that are parallel to each other and are connected by a connecting member on a silicon substrate, a first optical waveguide formed on at least one cantilever, and Opposed to one optical waveguide, the plurality of cantilevers are deformed in a first direction or a second direction opposite thereto to optically couple with the first optical waveguide on the cantilever. A plurality of second optical waveguides formed on the substrate, a switch driving means for deforming the cantilever, and a position on the connecting member of the cantilever where the connecting member comes into contact when the optical path is switched. And a layer protruding from the substrate in an eaves-like shape on both the substrate. Further, in the optical switch of the present invention, the material of the layer protruding from the substrate in the shape of an eaves is glass, preferably quartz glass. Furthermore, the optical switch of the present invention, the thickness of the layer protruding from the substrate in the shape of an eaves is 10 micrometers or more and 100 micrometers or less, preferably 20 micrometers or more and 80 micrometers or less, more preferably 30 micrometers or more and 60 micrometers. It is as follows. Further, in the optical switch of the present invention, the members between the second optical waveguides facing the interface where the optical path of the substrate is switched are recessed in the light propagating direction. The optical switch of the present invention has an electromagnetic actuator including a permanent magnet, a coil, and a magnetic material formed on the connecting member of the cantilever and on the substrate. Further, in the optical switch of the present invention, the cantilever connecting member, the permanent magnet, the coil, and the magnetic body are formed closer to the base of the cantilever than the longitudinal center thereof. Further, in the optical switch of the present invention, the cantilever connecting member, the permanent magnet, the coil, and the magnetic body are formed closer to the base side of the beam than the longitudinal center of the cantilever, and the optical waveguide connecting member is further provided. The cantilever is formed closer to the tip of the cantilever than the center of the cantilever in the longitudinal direction. Further, in the optical switch of the present invention, a precisely sized member is arranged at a position facing the side surface of the cantilever between the interface where the optical path of the substrate is switched and the connecting member of the cantilever. To do. The optical switch of the present invention, the width of the cantilever is 15 micrometers or more and 60 micrometers or less, preferably 25 micrometers.
It is set to be not less than 40 and not more than 40 micrometers. Further, in the optical switch of the present invention, the optical waveguide array pitch at the connection surface between the optical switch and the outside is made larger than the optical waveguide array pitch at the interface where the optical path is switched. In the optical switch of the present invention, the plurality of parallel cantilevers connected by the connecting member have the function of moving the tip portions of the connected beams in parallel with the optical path switching operation. Therefore, the optical waveguide formed on this cantilever also moves in parallel with the optical path switching operation. This parallel movement of the optical waveguide makes it possible to select and switch the optical waveguide on the output side. Further, in the present invention, the layer protruding in an eaves-like shape from the substrate provided on both the coupling member of the optical waveguide and the substrate at the position where the coupling member comes into contact when the optical path switching is performed is accompanied by an optical path switching operation. The optical waveguides on the emission side and the incidence side that are in contact with each other can be accurately aligned. By using glass as the material of the layer protruding from the substrate in the shape of an eaves, it is possible to prevent cracking or chipping when they come into contact with each other due to the optical path switching operation. Further, by using quartz glass, the difference in the coefficient of linear expansion from the silicon substrate can be reduced, and processing can be easily performed. Further, in the present invention, by making the thickness of the layer protruding from the substrate in the shape of an eaves 10 μm or more and 100 μm or less, there is no destruction when they come into contact with each other due to the optical path switching operation, and processing is also possible. It's easy.
More preferably, by setting it to 20 μm or more and 80 μm or less, the reliability at the time of repeated contact is improved and the processing accuracy is also improved, so that the alignment accuracy of the optical waveguide is improved. More preferably, by setting the thickness to 30 μm or more and 60 μm or less, it is possible to sufficiently withstand an impact load from the outside, improve the working accuracy, and shorten the working time. In the present invention, since the members between the optical waveguides facing the interface where the optical path is switched on the substrate are recessed in the light propagation direction, a machining allowance can be provided at the tip of the movable side optical waveguide. Precise machining of the side optical waveguide tip becomes easy. In addition, by setting the gap between the fixed-side and movable-side optical waveguides at the optical path switching interface to a negative value, the optical waveguides are brought into physical contact with each other, and the light at the optical path switching interface caused by reflection or scattering occurs. The loss can be minimized. In the present invention, a magnetic force is generated between the permanent magnet and the coil and the magnetic body formed on the connecting member of the cantilever and on the substrate. It is possible to switch the optical waveguide formed on the cantilever. Further, in the present invention, since the width of the cantilever is set to 15 μm or more and 60 μm or less, preferably 25 μm or more and 40 μm or less, the cantilever is bent with a force of 50 μnewton to 1 mmnewton. Therefore, the optical path can be switched using an electromagnetic actuator manufactured by a thin film process. In the present invention, since the connecting member of the cantilever, the permanent magnet, the coil and the magnetic body are formed at a position closer to the base side than the central portion in the longitudinal direction of the cantilever in which the input side optical waveguide is formed, When the tip of the cantilever can bend in the longitudinal direction of the beam, and the gap between the fixed-side and working-side optical waveguide tips is negative when the switch is not operating and the beam is not deformed. However, the tips of the optical waveguides can be brought into contact with each other. Further, in the present invention, the cantilever connecting member, the permanent magnet, the coil, and the magnetic body are formed closer to the base side of the beam than the longitudinal center of the cantilever, and the cantilever connecting member is a cantilever. Since it is formed on the tip side of the beam rather than the central portion in the longitudinal direction of
The tip of the cantilever can be bent in the longitudinal direction of the beam, and even if the gap between the optical waveguide on the optical path switching interface between the substrate side and the cantilever side is a negative value, the tips of the optical waveguides contact each other. Not only can it be moved, but it also becomes possible to move the tip of the optical waveguide while keeping it parallel,
It is possible to prevent an increase in insertion loss caused by the fact that the light exit surface and the entrance surface of the waveguide are not parallel to each other. Further, in the present invention, the member precisely positioned on the substrate at a position facing the side surface of the movable optical waveguide between the interface where the optical path is switched and the connecting member of the cantilever is a beam of the beam preceding the connecting member. Since the displacement is constrained, the optical waveguides can be aligned with each other with high accuracy even when the cantilever bends. Since the optical waveguide array pitch at the connection surface between the optical switch and the outside is made larger than the optical waveguide array pitch at the interface where the optical path is switched, it is easy to connect an optical transmission medium such as an optical fiber that extracts light from the optical switch. Become.

[0005]

DETAILED DESCRIPTION OF THE INVENTION

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of the present invention will be described in detail below with reference to the drawings. FIG. 1 is a perspective view of an embodiment of a waveguide type two-circuit 1 × 2 optical switch according to the present invention. 1 is an optical fiber, 2 is a movable side optical waveguide, 3 is a silicon substrate, 4 is a magnetic film, 5
Is a coil electrode, 7 is a thin film electromagnet, 8 is an optical fiber, 9
Is a fixed side optical waveguide, 11 is a connecting member, and 12 is a cantilever. The light input from the optical fiber 1 is transmitted to the movable side optical waveguide 2 formed on the cantilever 12. The ends of the cantilever 12 are connected by a connecting member 11, and the cantilever 12 can be displaced in the plane of the silicon substrate 3 while keeping parallel to each other. The magnetic film 4 is formed on the connecting member 11. On the silicon substrate 3 on both sides of the magnetic film 4, a thin film electromagnet 7 including a magnetic film, a permanent magnet and a thin film electromagnet is formed.
Are formed. Electric power is supplied to the thin film electromagnet 7 from a power source (not shown) via the coil electrode 5. The voltage can be set in the range of 3 to 10 volts. By changing the direction of the current flowing through the thin film electromagnets 7a and 7b, the magnitude relation of the forces acting on the thin film electromagnets 7a and 7b and the magnetic film 4 is reversed, and the moving position of the connecting member 11 is switched to connect the beam 12
By changing the deformation direction of, the fixed side optical waveguide 9 to which the movable side optical waveguide 2 is connected can be switched. In the embodiments of the present specification, the optical switch is driven by an actuator that is a combination of a permanent magnet, a coil, and a magnetic body, but other actuators suitable for driving the optical switch include a cantilever beam. An actuator that combines a magnetic body and a movable permanent magnet that is arranged outside the optical switch, an actuator that uses electrostatic force, an actuator that uses the piezo effect,
Or if there is an actuator that uses deformation of shape memory alloy or bimetal due to temperature change, and if it can generate the force necessary to switch the optical switch,
Can be used.

FIG. 2 is a top view of an embodiment of a waveguide type two-circuit 1 × 2 optical switch according to the present invention. The figure shows a state before the power is applied to the optical switch. 2a and 2b are movable side optical waveguides, 5a and 7a are coil electrodes and thin film electromagnets on the movable side optical waveguide 2a side, 5b and 7b, respectively.
Is a coil electrode and a thin film electromagnet on the movable side optical waveguide 2b side, 9a, 9b, 9c and 9d are fixed side optical waveguides, and 10 is a recess. The movable side optical waveguides 2a and 2b are provided with recesses 10 at the tips thereof as a machining allowance, and the movable side optical waveguides 2a and 2b are provided.
Also, the tip of the cantilever 12 can be precisely processed. When a current is applied to the thin film electromagnet 7a in a direction that strongly attracts the magnetic film 4 and a current is applied to the thin film electromagnet 7b in a direction that weakly attracts the magnetic film 4 (hereinafter referred to as A direction), the cantilever 12 is broken. The movable side optical waveguide 2a is displaced as shown in 121.
Is connected to the fixed side optical waveguide 9a, and the movable side optical waveguide 2b is connected to the fixed side optical waveguide 9c. Here, when the direction of the current flowing through the thin film electromagnets 7a and 7b is reversed (hereinafter referred to as B direction), the magnitude relationship of the electromagnetic force generated between the thin film electromagnets 7a and 7b and the magnetic film 4 is reversed, and The cantilever 12 is displaced as shown by a broken line 122, the movable side optical waveguide 2a is connected to the fixed side optical waveguide 9b, and the movable side optical waveguide 2b is connected to the fixed side optical waveguide 9d. This makes it possible to switch the optical path. Cantilever 1
2, since the movable side optical waveguides 2a and 2b are connected at their tips by the connecting member 11, the movable side optical waveguides 2a and 2b ahead of the connecting member 11 are used for switching the optical path by the principle of parallel leaf springs. It moves in parallel with it. Here, the operation of deforming the parallel leaf spring will be described with reference to FIG. FIG. 20 (a) is a diagram for explaining the deformation situation when a force is applied to the tip of the cantilever. 110 is a cantilever. When a force F is applied to the tip B of the cantilever 110, the cantilever 1
10 bends in the direction of force F, and point B moves to point B '. Further, the angle θ formed by the tangent line CD passing through the point B ′ and the line GH indicating the position of the fixed portion of the cantilever 110 is smaller than 90 °. That is, the tip of the cantilever 110 rotates by bending. FIG. 20 (b) is a diagram for explaining the deformation situation when a force is applied to the tips of the parallel leaf springs. 111 is a parallel leaf spring. The ends of the parallel leaf springs 111 are connected by a connecting member 112. When a force F is applied to the connecting member 112, the parallel leaf spring 1
11 bends in the direction of force F and points B1 and B2 move to points B1 'and B2'. At this time, the angle formed by the tangent line C1D1 passing through the tip B1 ′ and the line GH is kept at 90 °. Therefore, it can be seen that the tips of the parallel leaf springs 111 do not rotate even if bending occurs. Therefore, the tips of the optical waveguides formed on the parallel leaf springs of the optical switch of FIG. 2 move in parallel. In addition, the thin film electromagnets 7a and
Alternatively, since the permanent magnet in 7b attracts the magnetic film 4 and the cantilever 12 does not return to the initial position, the attenuation of light depending on the inclination of the optical axis at the optical path switching interface should be reduced. You can As a result, it is possible to realize a self-holding type optical switch with small light attenuation.

FIG. 3 is a view showing the structure of a thin film electromagnet used in the waveguide type two-circuit 1 × 2 optical switch according to the present invention. 20 is a thin film coil made of copper, 21 is a magnetic film made of Fe-Ni, 22
Is a magnetic film made of Fe-Ni, 23 is a magnetic film made of Fe-Ni, 24 is a fixed-side optical waveguide, 25 is a movable-side optical waveguide, 26 is a magnetic film made of Fe-Ni, 27 is Ne- Fe-B permanent magnet, 28 is a connecting member of the movable side optical waveguide. When current is passed through the thin film coil 20 with A as + and B as −,
The magnetic flux formed by the thin-film coil 20 and the magnetic film 21 strengthens the magnetic flux of the permanent magnet 27 in the magnetic film 22, and the coupling member 28
The magnetic film 23 formed above is strongly attracted, and the connecting member 28
Moves in the direction of arrow C and is attracted to the magnetic films 22 and 23. When current is applied to the thin-film coil 20 with A as − and B as +,
The magnetic flux formed by the thin-film coil 20 and the magnetic film 21 cancels out the magnetic flux of the permanent magnet 27 in the magnetic film 22, weakening the force of attracting the magnetic film 23 formed on the connecting member 28, and connecting the magnetic film 23. The member 28 is made of the magnetic film 22 by the elasticity of the movable beam 25.
And 23. In the present invention, as shown in FIG. 2, thin film electromagnets are arranged on both side surfaces of the connecting member so that the magnetic film 23 on the connecting member 28 can be effectively attracted. Further, in the thin-film electromagnet shown in FIG. 3, even if the current flowing through the thin-film coil 20 after the connecting member 28 is attracted to the magnetic films 22 and 23 is set to 0, the magnetic flux of the permanent magnet 27 is changed to the magnetic films 22 and 23.
And through the closed magnetic circuit formed by 26 and 26,
A strong adhesive force continues to work on the magnetic film 23. As a result, even if the current passed through the thin film coil 20 is set to 0, the connecting member is continuously attracted to the magnetic films 22 and 23, and the light switching state is maintained. Furthermore, by setting the width of the cantilever of the waveguide type two-circuit 1 × 2 optical switch according to the present invention to 15 μm or more and 60 μm or less, preferably 25 μm or more and 40 μm or less, it is possible to reduce the width from 50 μNewton. Since the cantilever can be deflected with a force of 1 millinewton, the voltage supplied to the electromagnetic actuator manufactured by the thin film process can be driven at a set value within the range of 3 to 10 volts, and the optical path can be changed. You can switch. FIG. 4 is a diagram showing a cross-sectional structure of a thin film coil portion in a thin film electromagnet used in a waveguide type two-circuit 1 × 2 optical switch according to the present invention. 20a is the lower wire of the copper thin film coil, 20b is the upper wire of the thin film coil, 71, 73 and 75 are insulating layers made of polyimide, and 21 is
A magnetic film made of Fe-Ni, 76 is a through hole formed in the insulating layer 73 made of polyimide, 77 is a through hole formed in the insulating layer 71 made of polyimide, and 3 is a silicon substrate. The lower wire 20a of the copper thin-film coil is formed on the silicon substrate 3, the insulating layer 73 made of polyimide is formed thereon, the through hole 76 is formed, and then firing is performed. Next, a Fe-Ni magnetic film 72 is formed by vapor deposition or sputtering. Further, an insulating layer 73 made of polyimide is formed thereon, a through hole 77 is formed, and then firing is performed. The upper wire 20b of the copper thin-film coil is formed thereon, and the insulating layer 75 made of polyimide is further formed and fired. The bottom wire 20 of the thin-film coil
The a and the upper wire 20b of the copper thin-film coil are connected through the through holes 76 and 77 to form a coil with the Fe-Ni magnetic film 72 as the core. Although copper was used as the material of the wire of the thin film coil in this embodiment, any material having conductivity such as aluminum, nickel, and gold can be used.

FIG. 5 is a top view of another embodiment according to the present invention. 15
Is a fixed-side optical waveguide. Since the arrangement pitch of the fixed-side optical waveguides 15 on the connection surface between the optical switch and the outside is made larger than the arrangement pitch of the fixed-side optical waveguides 15 on the interface where the optical path switching is performed, the optical fiber 8 can be easily connected. FIG. 6 is a perspective view of another embodiment of the waveguide type two-circuit 1 × 2 optical switch according to the present invention. 18 is a quartz glass layer. It has a structure in which a silica glass layer 18 having a thickness of 40 micrometers is provided on the silicon substrate 3. The quartz glass layer 18 formed on the connecting member 14 comes into contact with the quartz glass layer 18 formed under the thin film electromagnet 7 when the optical path is switched, so that the movable side optical waveguide 2 and the fixed side optical waveguide 9 are precisely Can be aligned with. FIG. 7 is a sectional view of the waveguide type two-circuit 1 × 2 optical switch shown in FIG. Since the quartz glass layers 18 contact each other, the movable-side optical waveguide 2 is aligned with high precision,
A highly efficient optical connection can be realized. FIG. 8 is a top view of another embodiment according to the present invention. 12
Reference numerals a and 12b are movable side optical waveguides, 13a, 13b and 13c are precisely positioned members, and 14 is a connecting member. Member 13a, 1
3b and 13c are integrally processed with the silicon substrate 3.

FIG. 9 is an explanatory diagram showing the operation of the switch shown in FIG. Reference numeral 17 denotes a gap between the movable side optical waveguide and the fixed side optical waveguide at the light switching interface. The initial state shown in FIG. 9 (a) shows a state in which no current is applied to the optical switch shown in FIG. The energized state shown in FIG. 9 (b) shows a state in which current is applied to the optical switch shown in FIG. The current disconnection state shown in FIG. 9 (c) shows a state in which the current applied to the optical switch shown in FIG. 8 is disconnected. In the energized state, the movable side optical waveguides 12a and 12b are bent by the action of magnetic force as shown in the figure. Even in this case, the distal ends of the movable side optical waveguides 12a and 12b are restrained from being displaced by the members 13a and 13b, so that they do not deviate from the connection position with the fixed side optical waveguides. Further, by bending the movable-side optical waveguides 12a and 12b, a larger gap 17 is created between the movable-side optical waveguide and the fixed-side optical waveguide than when there is no curvature.
The movable side optical waveguide is lengthened in advance by the width of this gap 17. When the current flowing to the thin film electromagnet 7 is cut after the optical path switching operation is performed, the degree of bending of the movable side optical waveguide is reduced, so that the gap between the gaps 17 is narrowed, and the movable side optical waveguides 12a and 12b and the fixed side optical waveguides 9a and 9c. The connection surface with can be physically contacted. Since the thin film electromagnet 7 and the magnetic film 4 are attracted to each other even after the current flowing through the thin film electromagnet 7 is cut off, the cantilevers 12a and 12b do not return to their initial positions. As a result, good optical connection with less reflection and scattering at the connection interface due to contact between the waveguides can be performed. If current is passed in the opposite direction, the movable side optical waveguides 12a and
The 2b and the fixed-side optical waveguides 9b and 9d physically contact with each other, and good optical connection with less reflection and scattering at the connection interface is possible, and self-holding type optical switching with less insertion loss can be realized.

FIG. 10 is a top view of an embodiment of an optical switch array consisting of 8 circuit 1 × 2 optical switches according to the present invention. 12a, 12
b, 12c, 12d, 12e, 12f, 12g and 12h are cantilevers, 2a, 2
b, 2c, 2d, 2e, 2f, 2g and 2h are movable side optical waveguides, 10a,
10b, 10c, 10d, 10e, 10f, 10g and 10h are indentations, 16a,
16b, 16c, 16d, 16e, 16f, 16g, 16h, 16i, 16j, 16k,
16l, 16m, 16n, 16o and 16p are fixed side optical waveguides. Cantilevers 12a, 12b, 12c, 12d, 12e, 12f, 12g and 12h
Are connected by a connecting member 11 and can be displaced in the plane of the substrate while keeping parallel to each other. The movable side optical waveguides 2a, 2b, 2c, 2d, 2e, 2f, 2g and 2h have dents 10a, 10b, 10c, 10d, 10e, 10f, 10g and 1 as machining allowances at their tips.
Since 0h is provided, the movable side optical waveguide and the tip of the cantilever can be precisely processed. A film-shaped magnetic film 4 is formed on the connecting member 11. Thin film electromagnets 7 are formed on the silicon substrate 3 on both sides of the magnetic film 4. Electric power is supplied to the thin film electromagnet 7 from a power source (not shown) via the coil electrode 5. By changing the direction of the current flowing through the thin film electromagnet 7, the magnitude relationship of the electromagnetic force generated between the thin film electromagnets 7a and 7b and the magnetic film 4 is reversed, and the movable side optical waveguides 2a, 2b, 2c, 2d. , 2e, 2f, 2g and 2h
Fixed side optical waveguides 16a, 16b, 16c, 16d, 16e, 1
6f, 16g, 16h, 16i, 16j, 16k, 16l, 16m, 16n, 16o and 16p can be switched. Thin film electromagnets 7a and 7b
Even after cutting off the electric current flowing through the cantilever beam 12 by the action of the permanent magnets in the thin film electromagnets 7a and 7b, the cantilever 12
The a, 12b, 12c, 12d, 12e, 12f, 12g and 12h never return to the initial position. By thus forming the optical switches in parallel on the same substrate, a small-sized self-holding type optical switch array can be realized.

FIG. 11 is a top view of an embodiment of an optical switch tree consisting of 8-circuit 1 × 2 optical switches according to the present invention. 30 is a two-system input side waveguide of A and B, 31 is a first optical switch, 32
Is an optical waveguide connecting the optical switches, 33 is a second optical switch, 34 is a third optical switch, 35 is an output optical waveguide of the second optical switch consisting of four systems of A0, A1, A2 and A3, and 36 is B0,
It is an output side optical waveguide of the third optical switch composed of four systems of B1, B2 and B3. As shown in the figure, a two-circuit 1 × 4 optical switch can be realized by directly connecting the output side optical waveguide of the first optical switch to the input side optical waveguides of the second optical switch and the third optical switch.

FIG. 12 is an explanatory diagram showing the operation of the optical switch tree shown in FIG. In the figure, state 0 is set when the switch is connected to the left side in the direction of light propagation, and state 1 is set when the switch is connected to the right side in the direction of light propagation. . As shown in the figure, if the states of the second optical switch and the third optical switch are the same, the inputs A and B are changed depending on the combination of the states with the first optical switch.
And can output to the same position, and a two-circuit 1 × 4 optical switch can be realized.

FIG. 13 is a block diagram of an optical signal transmission device using a two-circuit 1 × 2 optical switch according to the present invention. In the optical communication network, the optical fiber is duplicated with 0 system and 1 system in order to secure the reliability of the communication network. The audio electrical signal can be electrically switched between 0 system and 1 system, but since the video signal is input as an optical signal, 0 system and 1 system are switched by an optical switch. In this way, if a failure occurs in one optical fiber, communication can be continued using the other optical fiber. 40 is an optical switch, 41 is a voice electric signal, 42 is an electric / optical signal converter, 43 is an optical information transmission section, 44 is a 0-system optical fiber,
45 is a 1-system optical fiber, 46 is an output connector, 47 is an optical switch controller, 48 is a video optical signal input side connector, 49 is a voice electrical signal input side connector, 50 is a video optical signal input, 51 is a voice electrical signal input Is. An audio electrical signal input 50 and a video optical signal input 51 are input to the optical information transmission unit 43, and the video optical signal input is routed by the optical switch of the present invention and input to the electrical / optical signal converter 42 for conversion. Optical signals are output to the 0 and 1 system optical fibers. The optical switch 40 is arranged at least between the input end and the electric / optical signal converter 42 or between the output end 46 and the electric / optical signal converter 42. By using the optical switch of the present invention, it is possible to realize a data transmission unit for optical communication which can be produced at low cost and can be driven at a low voltage. Since this data transmission unit has a small transmission loss and can be driven by a low voltage, it can be used as an optical communication device for personal computers and personal digital assistants.

FIG. 14 is a sectional view of the packaged optical switch. 55 is a cover, 56 is a thin film electromagnet, 57 is quartz glass,
Reference numeral 58 is a magnetic film, 59 is a power line for a thin film electromagnet, 60 is an electrode pin, 61 is a silicon substrate, 62 is a movable side optical waveguide formed on a beam, 63 is a connecting member, 64 is a substrate and 65 is a thin film. It is a power line for an electromagnet. Since the optical switch is hermetically sealed by using the cover 55 and the substrate 64, it is possible to prevent the ingress of oxygen and water in the air that causes foreign matter or corrosion and deterioration that causes malfunction, and thus reliability is improved. A high optical switch can be constructed.

FIG. 15 shows an embodiment in which the optical switch according to the present invention is applied to a bypass switch. Reference numeral 83 is a fiber cable for passing light, and 87 is an optical fiber cable for returning light. Pass the optical signal by changing the connection destination of the optical signal,
It is possible to switch whether to return an optical signal through the optical fiber cable 87 for return light.

FIG. 16 shows an embodiment in which the optical switch according to the present invention is applied to an optical communication network. 80 is an optical communication line, 81 is an optical connector,
82 is an optical switch unit using the optical switch of the present invention,
83 is a fiber cable for passing light, 84 is an inspector, 85 and
86 is a propagation path of an optical signal, and 87 is an optical fiber cable for returning light. When the contact A of the optical switch is closed, the optical signal is transmitted through the optical fiber for connection 85 through the optical communication line 80.
You can go back to. The contact B of the optical switch is closed during the periodic inspection of the optical communication network. Since the optical signal is transmitted from the connector B to the inspector through the propagation path 86 by the optical fiber cable, various analyzes and investigations can be performed.

FIG. 17 shows an embodiment in which the optical switch according to the present invention is applied to an interconnect between devices. 100 is an optical bus inside the equipment, 81 is an optical connector, 82a and 82b are optical switch units, 101 is an optical fiber cable for connecting external equipment, 102 is external equipment, 85 and 86 are optical signal propagation paths, and 87 is return light It is an optical fiber cable. The apparatus in 100 is an information communication device, a computer, a telephone, an information terminal, a circuit or device for transmitting information using light, or an integrated circuit or device of the circuit or device, and a combination thereof. When the contact A of the optical switch is closed, the optical signal can return to the optical bus 100 inside the computer by the propagation path 85 through the connecting optical fiber. When connecting an external device, the contact B of the optical switch is closed. The optical signal can reach the external device 102 from the connector B through the external device connecting optical fiber cable 101. According to the present invention, it is possible to realize an interconnect between devices that transmit information by using inexpensive and highly reliable light. It is possible to realize an inexpensive and highly reliable interconnect that can be used in information communication devices, computers, particularly small information terminals, telephones, portable information communication terminals, etc., that can be driven at a low voltage.

FIG. 18 shows an embodiment of a connection path switching device for optical communication according to the present invention. Reference numeral 120 is an optical switch or optical switch array of the present invention, 121 is an optical switch tree 122, 123, or 124 of the optical switch or optical switch array of the present invention, which is an optical fiber cable of an optical communication network. The optical signal input from the cable 122 can be switched between the connection paths to the optical fibers 123 and 124 to be connected by the optical switch tree formed by the optical switch or the optical switch array. The connection path is arranged so that it can be achieved by a combination of optical switches and optical switch arrays 120. In this way, the connection path is distributed so that the part 123 of the optical fiber of the connection destination is connected to another path switching device and the part 124 of the other optical fiber is connected to the path switching device or the optical-electrical conversion device on the more distal side. To be done. Further, even if a part of the communication network is disconnected due to a failure or the like, it is selected so that another path can be connected. By using an optical switch with a small insertion loss, an optical switch array, or an optical switch tree configured by connecting the optical switches in series or in parallel according to the present invention, a compact and highly integrated optical communication main It is possible to realize a communication path switching device such as a wiring board or a cross connect. Furthermore, since the switching work is automated and the individual drive voltage is low, it is possible to realize a communication line connection switching device that can be operated at low maintenance costs. Therefore, the reliability of the entire communication network can be improved.

FIG. 19 is a diagram schematically showing the manufacturing process of the optical switch according to the present invention. 18a is a lower silica glass layer having a thickness of 25 micrometers, 18b is an upper silica glass layer having a thickness of 25 micrometers, 90 is an optical waveguide core, 91 is a groove, 92 is a groove, and 93 is a hole. First, a lower quartz glass layer 18a having a thickness of 25 μm is formed on the silicon substrate 3. Next, the optical waveguide core 90
And an upper quartz glass layer 18b having a thickness of 25 μm is formed. Next, a groove 91 is formed in the quartz glass layers 18a and 18b by selective dry etching. Next, this quartz glass layer
A groove 92 is formed in the silicon substrate 3 by selective dry etching using 18a and 18b as a mask. Next, the through hole structure is obtained by processing the hole 93 from the silicon substrate side by wet etching. The side surface of the groove 92 formed in the silicon substrate 3 by selective dry etching does not protrude beyond the quartz glass layers 18a and 18b due to side etching. Therefore, the quartz glass layer 18 used for alignment
Accurate alignment is possible without disturbing the contact between a and 18b.

[0020]

【The invention's effect】

According to the present embodiment, there is an effect that it is possible to realize a self-holding type optical switch in which the attenuation of light depending on the inclination of the optical axis at the optical path switching interface is small.

[Brief Description of the Drawings] FIG. 1 is a perspective view of an embodiment of a waveguide type two-circuit 1 × 2 optical switch according to the present invention. FIG. 2 is a top view of one embodiment of a waveguide type two-circuit 1 × 2 optical switch according to the invention. FIG. 3 is a top view showing the structure of the thin-film electromagnet of the waveguide type two-circuit 1 × 2 optical switch according to the present invention. FIG. 4 is a sectional view of a thin-film electromagnet of a waveguide type two-circuit 1 × 2 optical switch according to the present invention. FIG. 5 is a top view of another embodiment according to the present invention. FIG. 6 is a perspective view of another embodiment of the waveguide type two-circuit 1 × 2 optical switch according to the present invention. FIG. 7 is a sectional view of the waveguide type two-circuit 1 × 2 optical switch shown in FIG. FIG. 8 is a top view of another embodiment according to the present invention. FIG. 9 is an explanatory diagram showing the operation of the switch shown in FIG. FIG. 10 is a top view of an embodiment of an optical switch array consisting of 8-circuit 1 × 2 optical switches according to the present invention. FIG. 11 is a top view of an embodiment of an optical switch tree consisting of three two-circuit 1 × 2 optical switches according to the present invention. FIG. 12 is an explanatory diagram showing the operation of the optical switch tree shown in FIG. FIG. 13 is a structural diagram of an optical communication device using a two-circuit 1 × 2 optical switch according to the present invention. FIG. 14 shows two circuits 1 according to the invention packaged
It is sectional drawing of a * 2 optical switch. FIG. 15 is a structural diagram of a bypass switch using a two-circuit 1 × 2 optical switch according to the present invention. FIG. 16 is a block diagram of a switch for connecting a tester of an optical communication network using a bypass switch composed of a two-circuit 1 × 2 optical switch according to the present invention. FIG. 17 is a block diagram of an interconnect between devices using the optical switch according to the present invention. FIG. 18 is a structural diagram of an optical communication connection path switching device using an optical switch according to the present invention. FIG. 19 is an explanatory view showing the manufacturing process of the two-circuit 1 × 2 optical switch according to the present invention. FIG. 20 is a schematic diagram for explaining the deformation when a force is applied to the ends of the cantilever and the parallel leaf spring.

─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Teruhisa Akashi 4-8-15-B 205 Shibasakidai, Abiko City, Chiba Prefecture (56) References JP-A-59-24804 (JP, A) JP-A-55-156903 (JP, A) Actual Development Sho 55-35725 (JP, U) European Patent Application Publication 451018 (EP, A 1) E.P. OLLIER, et. al. , Micro-opt mechanical switch integrated on silicon, ELEC TRONICS LETTERS, November 9, 1995, Vol. 31, No. 23, pp. 2003-2005 (58) Fields surveyed (Int.Cl. ⁷ , DB name) G02B 26/08 G02B 6/26 JISST file (JOIS)

Claims (18)

(57) [Claims] 1. An optical switch having a cantilever-shaped movable member, wherein an optical waveguide is formed on the movable member, and the movable member is deformed to switch an optical path of an input optical signal. Cantilever beams parallel to each other and connected by a connecting member, a first optical waveguide formed on at least one cantilever beam, and a plurality of the cantilever facing the first optical waveguide. A plurality of second optical waveguides formed on a substrate, wherein the beam is deformed in a first direction or a second direction opposite thereto to optically couple with the first optical waveguide on the cantilever. Switch driving means for deforming the cantilever, and a region in which a member between the second optical waveguide facing the interface where the optical path of the substrate is switched is recessed in the light propagation direction, Deform the cantilever to switch the optical path, The first waveguide is formed so as to face the recessed region when the cantilever is not deformed, and the second waveguide is formed so as to face the second waveguide when the cantilever is deformed. Characteristic waveguide type optical switch. 2. An optical switch in which an optical waveguide is formed on a cantilever-shaped movable member and the movable member is deformed to switch the optical path of an input optical signal, wherein a plurality of parallel and connecting members are provided on a silicon substrate. A cantilever, a first optical waveguide formed on at least one cantilever, and a plurality of the cantilevers facing the first optical waveguide in a first direction. Alternatively, a plurality of second optical waveguides formed on the substrate, which are deformed in a second direction opposite thereto and are optically coupled to the first optical waveguides on the cantilever, and the cantilever A switch driving means for deforming, and a layer protruding in an eaves-like shape from the substrate both on the coupling member of the cantilever and on the substrate at a position where the coupling member comes into contact when optical path switching is performed, Facing the interface where the optical path of the substrate is switched And a region in which a member between the second optical waveguides is recessed in the light propagation direction, the switch driving means deforms the cantilever to switch the optical path, and the switch driving means is not driven. In the state, the first waveguide is formed so as to face the recessed region and to face the second waveguide when the switch driving means is driven, and the waveguide type light switch. 3. The waveguide type optical switch according to claim 2, wherein the layer protruding from the substrate in an eaves-like shape has a thickness of 10 μm or more and 100 μm or less. 4. The waveguide type optical switch according to claim 2, wherein the material of the layer protruding from the substrate in an eaves shape is glass. 5. The switch driving means forms a permanent magnet on one of the connecting member of the cantilever and the substrate and a coil and a magnetic body on the other side, and the permanent magnet, the coil and the magnetic body are formed. The waveguide type optical switch according to any one of claims 1 to 4, which is a switch driving means for deforming the cantilever beam by utilizing a magnetic force generated between the two. 6. A permanent magnet is formed on either one of the connecting member of the cantilever and the substrate, and a coil and a magnetic body are formed on the other of the connecting member and the coil. The waveguide type optical switch according to claim 5, wherein the waveguide type optical switch is formed on the base side. 7. An optical switch having a cantilevered movable member, wherein an optical waveguide is formed on the movable member, and the movable member is deformed to switch an optical path of an input optical signal. Cantilever beams parallel to each other and connected by a connecting member, a first optical waveguide formed on at least one cantilever beam, and a plurality of the cantilever facing the first optical waveguide. A plurality of second optical waveguides formed on a substrate, wherein the beam is deformed in a first direction or a second direction opposite thereto to optically couple with the first optical waveguide on the cantilever. A permanent magnet is formed on one of the connecting member of the cantilever and the substrate, and a coil and a magnetic body are formed on the other side, and the magnetic force generated between the permanent magnet and the coil and the magnetic body is used. And a switch driving means for deforming the cantilever beam, The connecting member of the cantilever, the permanent magnet, the coil and the magnetic body are formed closer to the base side of the beam than the longitudinal center of the cantilever, and another connecting member of the cantilever is formed. A waveguide type optical switch, characterized in that it is formed closer to the tip of the beam than the central part in the longitudinal direction, and the cantilever is deformed to switch the optical path. 8. An optical switch in which an optical waveguide is formed on a cantilever beam-like movable member and the movable member is deformed to switch the optical path of an input optical signal, wherein a plurality of parallel and connecting members are provided on a silicon substrate. A cantilever, a first optical waveguide formed on at least one cantilever, and a plurality of the cantilevers facing the first optical waveguide in a first direction. Or a plurality of second optical waveguides formed on a substrate, which are deformed in a second direction opposite thereto and are optically coupled to the first optical waveguides on the cantilever; On both the connecting member and the substrate at the position where the connecting member comes into contact when the optical path is switched, a layer protruding in an eaves shape from the substrate, and on the connecting member of the cantilever and on the substrate. A permanent magnet on one side and a coil and magnet on the other side. A switch driving means for forming a body and utilizing a magnetic force generated between the permanent magnet and the coil and the magnetic body to deform the cantilever, a connecting member of the cantilever, a permanent magnet, a coil, and A magnetic body is formed closer to the base of the beam than the center of the cantilever in the longitudinal direction, and another connecting member of the cantilever is formed closer to the tip of the beam than the center of the cantilever in the longitudinal direction. Then, the waveguide type optical switch is characterized in that the cantilever is deformed to switch the optical path. 9. A member precisely positioned on the substrate at a position facing a side surface of the cantilever between the interface for switching the optical path of the first optical waveguide and the connecting member of the cantilever. 9. The waveguide type optical switch according to claim 1, wherein the waveguide type optical switch is arranged. 10. The waveguide type optical switch according to claim 1, wherein the cantilever has a width of 15 micrometers or more and 60 micrometers or less. 11. The optical waveguide array pitch at the connection surface between the optical switch and the outside is set to be larger than the optical waveguide array pitch at the interface where the optical path switching is performed. Waveguide optical switch. 12. A waveguide type optical switch in which a plurality of the waveguide type optical switches according to any one of claims 1 to 11 are connected in parallel or in series or a combination of parallel and series on a substrate. 13. A waveguide type optical switch, wherein the waveguide type optical switch according to claim 1 is housed in an airtight container having an electrode. 14. A waveguide type optical switch according to claim 1, a controller for controlling the operation of the waveguide type optical switch, and the first optical waveguide of the waveguide type optical switch. An optical communication device, comprising: an optical signal connector connected to the optical waveguide; and a plurality of optical signal connectors connected to the second optical waveguide of the waveguide optical switch. 15. The waveguide type optical switch according to claim 1, wherein when the cantilever is deformed in one of the deformation directions, the cantilever is optically coupled to the first optical waveguide. An optical switch in which the second optical waveguides to be coupled are connected to each other. 16. The waveguide type optical switch according to claim 1, wherein the first optical waveguide is connected to an optical communication line, and the cantilever is in one of the deformation directions. The second optical waveguides that are optically coupled when deformed are connected to each other, and the second optical waveguides that are optically connected when deformed in the other deformation direction are connected to a predetermined inspection device. An optical switch for optical communication network inspection. 17. The waveguide type optical switch according to claim 1, wherein the first optical waveguide is connected to a device for transmitting optical information, and the cantilever is a modification of either one. The second optical waveguides that are optically coupled when deformed in one direction are connected to each other, and the second optical waveguides that are optically connected when deformed in the other deformation direction are connected to a device different from the device An interconnect for optical communication, which is connected to a connector. 18. The waveguide type optical switch according to claim 12, wherein the first and second optical waveguides which are not connected to other optical waveguides are connected to a plurality of optical communication optical fiber cables, An optical communication network connection path switching device for switching a connection path of an optical communication line by a switching operation of the waveguide type optical switch and a combination of the switching operations.