WO2004068209A1 - Self-hold optical switch - Google Patents

Abstract

A small, self-hold optical switch with less insertion loss variation for switching an optical path by driving a light reflector. The optical switch comprises a fixed block holding input/output optical fibers with their open ends arranged parallel on a plane and a movable block having a light reflector and movable in a plane parallel to the former plane between the position at which the reflector inputs an optical signal into one of the output optical fibers and the position at which the light reflector inputs an optical signal into the other output optical fiber. The optical switch further comprises first movement limiting means for limiting the movement of the movable block between the two above-mentioned positions in the plane on which the input/output optical fibers are provided and second movement limiting means for substantially inhibiting the movement of the movable block in the direction parallel to the optical axes of the optical fibers. The variation of the posture of the light reflector and the variation of the distances between the light reflector and the open ends of the optical fibers can be reduced to a very small level. As a result, the insertion loss variation is below 0.5 dB.

Description

 Description Self-holding optical switch

 The present invention relates to an optical switch mainly used for switching optical paths in the optical communication field. Background art

 In recent years, with the widespread use of the Internet, it is necessary to cope with an increase in communication speed and a sharp increase in the amount of information, and communication from electrical signals to optical signals is shifting. With the expansion of the optical communication network, the importance of optical switches used for switching and connecting optical paths is increasing.

When optical switches are classified according to the switching method, there are a method of electrically or optically changing the refractive index and phase of the optical path to switch the traveling direction of light, and a method of mechanically moving the optical path to switch the traveling direction of light. is there. Mechanical optical switches not only have the advantages of low insertion loss and low crosstalk, but also can easily realize a self-holding type that maintains the switched state if no drive power for switching is supplied. , Many are used. The purpose of optical path switching is not only for line switching, but also for maintenance and inspection purposes where a disconnected transmission path is switched to another path. An optical switch is composed of a combination of multiple basic 1 X 2 optical switches, such as 1 XN (N is a natural number) optical switch, matrix switch, etc., or together with other components in the optical component module. It is used by being incorporated in. For example, a 1 XN optical switch is packaged by connecting (N-1) 1 X 2 optical switches, so that the package containing the 1 XN optical switch becomes large, making it difficult to reduce the size. In addition, the matrix switch has a large number of channels, such as 32 × 32, so that even if the individual 1 × 2 optical switches are small, the matrix switch as a whole becomes large. In addition, when an optical switch is inserted into an optical component module, a plurality of optical switches are combined with other optical components in a case of a predetermined size. Subject to size constraints to fit together. When a 1XN optical switch, a matrix switch, an optical component module, or the like is configured with a mechanical optical switch, it is important to reduce the size of the basic 1X2 mechanical optical switch.

An optical communication device is configured by combining a plurality of optical devices.However, if the insertion loss of each optical device is large, the insertion loss increases and the signal decreases, so each optical device including an optical switch Requires a reduction in import loss. In a mechanical optical switch, a movable block that holds the output optical fiber because a slight shift in the position where the light beam emitted from the input optical fiber is coupled to the output optical fiber leads to an increase in insertion loss. The stop position must be very accurate. One example of a mechanical optical switch is disclosed in Japanese Patent No. 3,382,209. This outline is shown in a cross-sectional view in FIG. 10 using the mechanism section of the 2 × 4 optical switch. In this mechanical optical switch 300, the movable side (input) optical fiber 1321 and the fixed side (output) optical fiber 1322 have a gap of about 10 / m between their open ends. Hold and face. A fixed block 332 is held near the open end of the fixed-side optical fiber 1322. The movable-side optical fiber 321 is held by a support block 326 at a position distant from its open end, and a movable block 334 is held near its open end. The fixed block 3 3 2 and the movable block 3 3 4 are made of a soft magnetic material, and these two blocks 3 3 2 and 3 3 4 are arranged at an interval of several 100 μm. I have. In this optical switch 300, the movable block 3 3 4 is moved in parallel with the fixed block 3 3 2 by the electromagnetic actuator 350 to move the movable side optical fiber 3 2 1 and the fixed side optical fiber 1 3 Switch the optical path between 2 and 2. The electromagnetic actuator 350 includes a yoke 3552 having an almost E-shape, coils 3772a and 3772b wound on the legs at both ends of the yoke, and permanent magnets 3664 and It consists of a fixed block 3 32. One end of the guide bin 382 is slidably inserted into the oblong groove 383 formed in the movable block 334 of the soft magnetic material. The other end of the dobin 382 is fixed to a fixed block 332 made of a soft magnetic material. The movable area of the movable block 334 is defined by the width of the oval groove 383 into which the guide bin 382 is inserted. Outer diameter of guide bin 3 82, position of fixing block 3 32 for fixing guide bin 3 82, The shape and the position of the oblong groove 383 in which the movable block 3 3 4 into which the guide bin 3822 is inserted are made with high accuracy with a tolerance of / Xm unit or less. By manufacturing them with high precision, even if the movable optical fiber moves and the optical path is switched, highly accurate positioning with the fixed optical fiber becomes possible, and the insertion loss can be reduced.

 When the movable block 3 3 4 is held at one position by the magnetic force generated by the permanent magnet 3 6 4 acting through the yoke 3 5 2, the movable optical fiber 3 2 1 moves to the position indicated by the solid line. It is in. When the movable block 3 3 4 is in this position, a current flows from a power supply (not shown) to one coil 3 72 a in a direction to weaken the magnetic flux in one leg of the yoke 3 52, for example. Conversely, when a current is applied to the other coil 3 7 2 b in a direction to increase the magnetic flux in the other leg of the yoke 3 52, the movable block 3 3 4 is attracted to the coil 3 7 2 b side and moves. The side optical fiber 3221 moves to the position shown by the broken line, and the movable block 3334 is held at that position even when the current is cut off. By reversing the direction of the current and passing currents in the opposite directions to the coils 372a and 3772b, the movable block 3334 is attracted to the coil 3772a, and the movable optical fiber 3 21 is switched to the position shown by the solid line and held. Thus, the position of the movable block 334 can be switched by changing the direction of the current flowing through the coils 372a and 372b. After the movable block 334 moves, it is held at the moved position by the magnetic force of the permanent magnet 365 acting through the yoke 3552 even when the current is cut off. In this switch, the movable optical fiber 1321 is used as a part of a support member of the movable block 334. If the length of the movable-side optical fiber is too short, the curvature of the movable-side optical fiber at the stop position increases, which causes an increase in insertion loss. Therefore, it was difficult to further reduce the size.

As an example of another mechanical optical switch, a 1 × 2 optical switch that switches the optical path using prism movement is disclosed in Japanese Patent Application Laid-Open No. 60-26221, and Japanese Patent Application Laid-Open No. 5 discloses a 1 × 2 optical switch that switches an optical path using V-groove mirror movement. In a mechanical optical switch with this structure, an input optical fiber and an output optical fiber are arranged on the same surface at a certain distance, and an optical reflector provided opposite the open end of the optical fiber is moved by an electromagnetic actuator. And switch the light path. Input optical fiber The light beam that exits from the mirror is reflected twice by a light reflector such as a V-groove mirror or prism, and the light is switched to the optical path by selectively coupling the light beam to one of the two output optical fibers. It is a switch. In an optical switch using a light reflector, the optical fiber can be arranged on only one of the electromagnetic actuators. If the light reflector is moved to switch the optical path, there is no need to move and bend the optical fiber and the length of the fiber is long. Since there is no restriction on the size, there is an advantage that the size can be easily reduced.

 Since the prism and the V-groove mirror have the same function of changing the optical path, the operation of the optical switch will be described using the V-groove mirror. FIG. 11 is a diagram for explaining the operating principle of a 1 × 2 optical switch utilizing the movement of a V-groove mirror. The 1 × 2 optical switch is composed of an input optical fiber 4 2 1, an output optical fiber 4 2 2 a, 4 2 2 b and a V-groove mirror 4 3 6. The angle between the two light reflecting surfaces 437a and 437b of the V-groove mirror 436 is approximately 90 °. The input optical fiber 1 4 1 and the output optical fiber 1 4 2 a and 4 2 b are arranged with their open ends arranged at regular intervals in the same plane. 4 3 6 are arranged. When the V-groove mirror 4 36 is located at the position shown by the solid line, the light emitted from the input optical fiber 4 2 1 is reflected from the light reflecting surface 4 3 7 b to the light reflecting surface 4 3 as shown by the solid line arrow. The light is reflected at 7a, the optical path is inverted, and the light is coupled to the output optical fiber 422a. When the V-groove mirror 436 is moved to the position shown by the broken line using an electromagnetic actuator or the like (not shown), the light exiting from the input optical fiber 421 becomes the optical path as shown by the broken arrow. The light is reflected from the light-reflecting surface 437a to the light-reflecting surface 437b, the optical path is inverted, and the light is coupled to the output optical fiber 142b, so that the output optical fiber 422a and the output optical fiber The optical path can be switched between 1 and 4 2 b.

 The light beam emitted from the open end of the optical fiber jumps in space while spreading by diffraction.

Re-enter another optical fiber. In order to efficiently couple one optical fiber to another optical fiber, it is necessary to arrange a lens at the open ends of these optical fibers and to condense the light beam. As the lens, a ball lens, a collimator lens in which an optical fiber and a lens are integrated, a lensed fiber, and the like are generally used.

In an optical switch using an optical reflector, the light beam emitted from the input optical fiber 1 Distance to be incident on or coupled to the output optical fiber (coupling length) Force Optical fiber This is considerably longer than a single-drive optical switch. Therefore, the position of the light beam coupled to the output optical fiber changes due to slight changes in the attitude of the light reflector and changes in the position due to the movement of the light reflector, and 50 optical switches using the light reflector are used. As shown in Fig. 12 for the frequency distribution graph of insertion loss for (N = 50), the variation of the insertion loss between the optical switches is from 0.3 to 1.3 dB (average 0.67 dB). ). As described above, although the optical switch using the optical reflector has a structure that can be miniaturized, the required accuracy of the stop position of the optical reflector is strict and the variation in insertion loss is likely to be large. there were. In particular, it was difficult to control the position and attitude when moving the optical reflector, and the insertion loss fluctuated greatly between the optical switches. Disclosure of the invention

 Therefore, an object of the present invention is to provide a small self-holding optical switch with little insertion loss fluctuation.

 The self-holding optical switch of the present invention

An input optical fiber with an open end,

A first output optical fiber having an open end,

A second output optical fiber having an open end,

A fixed block that arranges the open ends of the input optical fiber, the first output optical fiber, and the second output optical fiber, and holds the optical fibers in parallel in a plane; and

At least a portion is made of a soft magnetic material, has an optical reflector provided opposite to the fixed block, and the optical reflector is connected between the open end of the input optical fiber and the open end of the first output optical fiber. Between a first position for coupling an optical signal between the first position and an optical reflector whose optical reflector couples an optical signal between the open end of the input optical fiber and the open end of the second output optical fiber. And a movable block that can move in a plane parallel to the plane. The movable block is reciprocated between a first position and a second position, and the movable block is movable between the first position and the second position. With an electromagnetic actuator to hold the And

The movable block comprises: a first movement restricting means for restricting a movement of the movable block between a first position and a second position in the plane parallel to the plane provided with the optical fiber. Second movement restricting means for substantially inhibiting the movement of the movable block in the optical axis direction of the input optical fiber.

 The electromagnetic actuator is

The first yoke with the first pawn piece,

A second yoke with a second pole piece,

The first and second pole pieces sandwich the movable block between these two paw / repieces so that they can reciprocate,

A magnetic flux is emitted to the first and second yokes and the movable block, a first magnetic path is formed by the first yoke and the movable block, and a second yoke and the movable block are formed by the second yoke and the movable block. A permanent magnet constituting a second magnetic path,

A first coil member wound around the first yoke for adjusting magnetic flux between the movable block and the first pole piece; and

A second coil member wound around the second yoke for adjusting magnetic flux between the movable block and the second pole piece may be provided.

 In the self-holding optical switch according to the present invention, the first movement restricting means may include a guide pin provided on one of opposing surfaces of the movable block and the fixed block, and a guide pin provided on another surface. Guide,

The second movement restricting means may be flexible in a plane in which the movable block can move, and may be rigid in the optical axis direction of the input optical fiber.

BRIEF DESCRIPTION OF THE FIGURES

 FIG. 1 is an exploded perspective view of a self-holding optical switch according to a first embodiment of the present invention, FIG. 2 is a longitudinal sectional view of the self-holding optical switch of the first embodiment according to the present invention, and FIG. In the m-m sectional view of Fig. 2,

Fig. 4 is a sectional view taken along the line W-IV in Fig. 2. FIG. 5 is a sectional view taken along line V--V of FIG. 3, and FIG. 6 is a sectional view taken along line 図 --VI of FIG.

 FIG. 7 is a view for explaining various postures for installing the self-holding optical switch of the present invention.

 FIG. 8 is a graph showing a frequency distribution graph of insertion loss for 50 (N = 50) self-holding optical switches of the present invention which are laid flat.

 FIG. 9 is a longitudinal sectional view of a self-holding optical switch according to a second embodiment of the present invention, and FIG. 10 is a sectional view showing a 2 × 4 optical fiber one-drive optical switch.

 FIG. 11 is a diagram for explaining the operation principle of the 1 × 2 optical switch using the movement of the V-groove mirror, and

 Fig. 12 shows a self-holding optical switch using a conventional flat V-groove mirror.

It is a figure which shows the frequency distribution graph of the insertion loss about 0 pieces (N = 50). BEST MODE FOR CARRYING OUT THE INVENTION

Example 1

Embodiment 1 of a self-holding optical switch according to the present invention will be described in detail with reference to FIGS. The self-holding optical switch 100 has a housing 110 in which an input optical fiber 121 and an output optical fiber 122, a 122 b are arranged in a plane with open ends arranged side by side. Are held in parallel within. A V-groove mirror 1 36 is provided facing the open end of the optical fiber, and the V-groove mirror 1 36 is connected to the open end of the input optical fiber 1 2 1 and one of the output optical fibers 1 2 2 a ( A first position for transmitting (coupling) an optical signal between the open end of the first optical fiber and the open end of the input optical fiber. Moving between the open end of the output optical fiber 1 2 2b (sometimes referred to as the “second output optical fiber 1”) and the second position that propagates (couples) the optical signal It is provided to be able to. The housing 110 can be combined with a box-shaped bottom half 1 1 1 and an upper half 1 1 2, and houses an optical switch mechanism therein. The input optical fiber 1 2 1 and the output optical fiber 1 1 2 2 a, 1 2 2 enter the housing 110 through a groove formed in the housing wall. It is assumed that three optical fibers are lined up . After attaching the optical switch mechanism to the board 1 1 5 (for example, a glass plate) on the bottom of the bottom half of the housing 1 1 1 (for example, a glass plate), assemble the top half of the housing 1 1 2 on top of it The bottom half 1 1 1 and the top half 1 1 2 are fixed with an epoxy or other adhesive, and the groove passing through the optical fiber 1 is sealed with an epoxy or other adhesive. An index matching agent is injected into the housing through an injection hole (not shown) formed in the upper portion of the housing 110, and the entire optical switch mechanism is immersed in the index matching agent to open the optical fiber at the open end and the V-groove. A refractive index matching agent can be interposed between the mirror and the mirror.

 FIG. 1 is an exploded perspective view of a self-holding optical switch 100 in which an upper half 1 1 2 is assembled on a housing bottom half 1 1 1 having an optical switch mechanism therein and fixed with an adhesive. FIG. 2 is a longitudinal sectional view at the center of the optical switch mechanism. Figure 3 shows

2 is a cross-sectional view taken along the line m-m of FIG. 2, and shows the structure of the electromagnetic actuator 150, the positional relationship between the optical fibers 122, 122a, 122b and the V-groove mirror 136. FIG. 4 is a sectional view of FIG. 2 taken along the line IV—IV, showing a fixed block 126, a movable block 134, a support block 191 and a first block provided between them to restrict movement. The figure shows the relationship between the guide bin 182 and the oval guide hole 183 that function as the movement restricting means, and the two optical fibers 186 that function as the second movement restricting means. FIG. 5 is a cross-sectional view taken along the line VV of FIG. 3, and is also a front view of the movable block 134. FIG. 6 is a sectional view taken along the line VI-VI of FIG. 3, showing the fixing block 126, the optical fibers 1 121, 122a, 122b and the guide pins 182 fixed thereto. .

The optical fibers 121, 122a, 122b are fixed to a fixed block 126 mounted on a substrate 115 near their open ends. The fixed block 126 is made of soft magnetic ceramic single crystal Mn-Zn ferrite, and three V-grooves with a depth of 125 μπι are formed at 250 jm intervals on one surface of the fixed block 126 to input light. Fiber 121 is placed in the center V-groove, and output optical fibers 122a and 122b are installed in the V-grooves on both sides so as to sandwich input optical fiber 121. The three optical fibers 121, 122a, and 122b are held on one surface of the fixed block 126 so that their open ends are aligned in a straight line. Optical fiber in V-groove 1 The power glass 12 9 is placed on 21, 122 a and 122 b, and the cover glass 129 is adhesively fixed to the fixing block 126.

A V-groove mirror 136 is provided to face the open ends of the optical fibers 121, 122a, 122b via the microphone lens of the microphone lens array 128. The V-groove mirror 1336 formed a 90.03 ° V-groove in silicon by etching, and the inside of the V-groove was used as a reflection surface. Silicon, for transmitting light in the near infrared region used in the communication field, on the silicon, a 0. 2 m thick gold film, and further a 0. 25 m thickness as a reflection enhancing film S i O ₂ film , 0.1 7 111 thick Ding 10 ₂ film and the formed reflectance of the reflecting surface of the mirror is set to be 9 9.6%. The V-groove mirror 136 is provided on a mirror-supporting block 135 made of single crystal Mn—Zn ferrite, which is a soft magnetic ceramic, and the mirror-supporting block 135 and the V-groove mirror 13 6 constitutes a movable block 134. The movable block 134, that is, the V-groove mirror 133 moves the substrate 115 relatively between the fixed block 126 and the open end of the optical fiber between the first position and the second position. Reciprocate. When the V-groove mirror 1336 is in the first position, the optical signal output from the input optical fiber 121 propagates to the open end of the output optical fiber 122a, and the V-groove mirror 1336 In the second position, the optical signal output from the input optical fiber 1121 propagates to the open end of the output optical fiber 122b. Thus, the optical path is switched.

 The reciprocating motion of the movable block with respect to the open end of the optical fiber is performed between the first position and the second position in a plane parallel to the plane provided with the optical fibers 121, 122a and 122b. Need to be done between. Also, it is necessary to keep the distance between the movable block (V-groove mirror) and the open end of the optical fiber substantially unchanged. Therefore, the movable block is provided with first movement restricting means for restricting the movement of the movable block between the first position and the second position in a plane parallel to the plane in which the optical fiber is provided; Second movement restricting means for substantially prohibiting the movement of the movable block in the optical axis direction of the optical fiber.

A microphone aperture lens array 128 is attached to the open end of the input / output optical fiber of the fixed block 126. The micro lens array 128 is made of silicon, and three lenses are provided at a position corresponding to the open end of the input / output optical fiber at intervals of 250 μπι. ing. Since the center of each lens coincides with the center of each optical fiber, and the micro lens array 128 is bonded and fixed to the fixed block 126, even if the optical path passes through space, optical signals with little loss It is possible to communicate. However, since the microphone lens array is not essential in the present invention, the microphone lens array is excluded from the following description.

 The movable block 134 constitutes a part of the electromagnetic actuator 150, which is driven by the electromagnetic actuator 150. The electromagnetic actuator 150 has an E-shaped yoke 152 as shown in cross section in FIG. 3, and the E-shaped yoke 152 has two end legs 15 2 a, 15 2 b and a center. It has legs 15 2 c. The E-shaped yoke 15 2 has a back yoke 15 2 d, and one end leg 15 2 a from one end of the pack yoke 15 2 d faces the side surface of the soft magnetic material movable block 1 3 4 It extends to the position where it does. Then, the other end leg 152 b extends from the other end of the back yoke 152 d to a position facing the other side surface of the soft magnetic movable block 134. Each end leg 15 2 a, 15 2 b has a pole piece 15 4 a, 15 4 b facing the side of the movable block 13 4.

 The one end leg 15 2 a and the half of the back yoke 15 2 d on the end leg side can be collectively referred to as a first yoke. In addition, the other end leg 152b and the half of the back yoke 152d on the end leg side can be collectively referred to as a second yoke. The pole piece 15 5 a attached to one end leg 15 2 a is the first pole piece, and the pole piece 15 5 b attached to the other end leg 15 2 b is the second Can be called a pole piece.

 The movable block 1 3 4 can be moved back and forth between the first and second pole pieces 1 5 4 a and 1 5 4 so that the first pole piece 1 5 4 a and the movable block 1 3 4 There is a gap between one side surface and a gap between the second pole piece 1554b and the other side surface of the movable block 1334.

The center leg 15 2 c attached to the back yoke 15 2 d of the E-shaped yoke 15 2 is provided with a permanent magnet 16 4 and a soft magnetic block 13 2, and the center leg 15 2 c is provided to the movable block 1 34. The permanent magnet 16 4 is magnetized from the soft magnetic block 13 2 toward the back yoke 15 2 d or in the opposite direction. Have been. The permanent magnet 164 can be, for example, a neodymium iron boron sintered permanent magnet. Part of the magnetic flux from the permanent magnet 16 4 enters one end leg 15 2 a via the back yoke 15 2 d. After that, it enters the soft magnetic material movable block 1 34 via the first pole piece 1 54 a. Then, it returns to the permanent magnet 16 4 through the soft magnetic block 13 2. Therefore, the permanent magnet 16 4, the first half of the back yoke 15 2 d, one end leg 15 2 a, the first pole piece 15 4 a, the movable block 13 4, and the soft magnetic block 1 32 constitutes a first magnetic path.

 A part of the magnetic flux from the permanent magnet 164 enters the other end leg 152b via the knock yoke 152d. After that, it enters the soft magnetic movable block 1 34 via the second pole piece 15 4 b. Then, it returns to the permanent magnet 1 64 through the soft magnetic block 1 32. There, permanent magnet 16 4, second half of pack yoke 15 2 d, other end leg 15 2 b, second pole piece 15 4 b, movable block 13 4, soft magnetic block 1 32 constitutes the second magnetic path.

A first coil member 17 2 a and a second coil member 17 2 b are wound around one end leg 15 2 a and the other end leg 15 2 b, respectively. In order to supply power to the first coil member 17 2a and the second coil member 17 2b, leads are provided from two terminals provided in the housing to each coil member 17 2a. The two terminals are connected to an external power supply (not shown) and external leads 1 16a and 1 16b. The magnetic field generated between the two coil members 17 2 a and 17 2 b when a DC voltage is applied between their terminals between the first coil member 17 2 a and the second coil member 17 2 b Are connected in series so that the directions are reversed. When the movable block 1 34 is in the first position, a current is applied to the first coil member 17 2 a to cancel or weaken the magnetic flux generated by the permanent magnet, and the second coil member 17 2 b When a current is applied in the direction to increase the magnetic flux by the permanent magnet, the attractive force between the movable block 13 4 and the first pole piece 15 4 a is lost, and the movable block 13 4 The movable block 13 4 moves to the second pole piece 15 5 b side because it is sucked by 54 b. When the movable block 1 3 4 is attracted to the second pole piece 1 5 4 b and the movable block 1 3 4 is in the second position, the input optical fiber 1 2 1 becomes the V-groove mirror 1 3 6 The optical path is connected to the output optical fiber 1 1 2 2b through the optical path. In this state, even when the current flowing through the coil members 1-172a and 172-2 is cut off, the state where the movable block 1334 is attracted to the second pole piece 1554b by the permanent magnet 1664 is maintained. Is done.

 When the movable block 1 3 4 is attracted to the second pole piece 1 5 4 b, a current is applied to the second coil member 17 2 b to cancel or weaken the magnetic flux generated by the permanent magnet. When a current is applied to the coil member 1 7 2 a to increase the magnetic flux of the permanent magnet, the movable block 1 3 4 moves away from the second pole piece 1 5 4 b and toward the first pole piece 1 5 4 a. Reach the first position. As a result, the input optical fiber 1121 is connected to the output optical fiber 122a via the V-groove mirror 133. In this state, the connection is maintained even if the current flowing to the coil member is turned off.

 When the movable block 1 34 is in the first position, there is a gap of about 100 μm between the first pole piece 15 4 a and one side of the movable block 13 4 When the block 1 34 is in the second position, make sure that there is a gap of about 100 m between the second pole piece 15 4 b and the other side of the movable block 1 34. I'm familiar. If this gap is small, a large current must be passed through the coil member when switching, and if the gap is large, the self-holding force for maintaining the movable block in the first or second position is reduced, and the impact resistance of the optical switch is reduced. Is reduced.

The self-holding type optical switch according to the present invention includes a first movement for restricting a movement of the movable block between a first position and a second position in a plane parallel to a plane provided with the optical fiber. A regulating means is provided on the movable block. In the self-holding optical switch 100 of Example 1, two oblong guide holes 18 3 provided in the movable block 13 4 as the first movement restricting means, and a fixed block 1 2 6 And two guide bins 182 which are fixed to the movable block 13 and are respectively engaged with the guide holes 183 of the movable block 134. The guide pin 18 2 is made of a non-magnetic material, for example, a non-magnetic cemented carbide, ceramitas, stainless steel, or the like, and has a cylindrical shape. The two guide bins 182 are fixed in parallel with each other by embedding one end thereof in a fixing block 126. Preferably, as shown in FIG. 6, a plane parallel to the plane formed by the optical fibers 1 2 1, 1 2 2 a 1 2 2 b on the fixed block 1 2 6 The two guide bins 18 2 are arranged so as to form The fixed block 1 26 has a V-depth of 300 μm on the surface opposite to the three V-grooves that fix the optical fibers 1 2 1, 1 2 a and 1 2 b. Two grooves are formed. Guide pins (diameter: 300 zm) made of nonmagnetic cemented carbide are inserted into each of the V-grooves with one end protruding, and are adhered and fixed using a cover glass. The guide pin 182 used here has a rigidity of more than 8.5 Kgf in bending force of 0.1 μm per 100 μm. I could do it. The other end of the guide bin 18 2 projecting from the fixed block 1 26 is engaged with the guide hole 18 3 of the movable block 13 4. The two guide holes 1 8 3 form a plane parallel to the plane formed on the fixed block 1 2 6 by the optical filters 1 2 1, 1 2 a and 1 2 b, The movement of the movable block 134 is limited to a plane parallel to the plane formed by the three optical fibers. The movable block reciprocates between the first position and the second position by moving the length of the guide hole 183 (length in the horizontal direction in Fig. 5) formed in the movable block 1 34. To match the stroke you want. The width of the guide hole 18 3 (vertical width in Fig. 5) is such that the guide bin 18 2 can freely enter the guide hole and move, but there is almost no gap between it and the guide bin. It is made with high precision. The cross-sectional shape of the guide hole 18 3 is not limited to an oval, but may be a trapezoid or a rectangle.

 The movement of the movable block is restricted between the first position and the second position in a plane parallel to the plane in which the optical fiber is provided by the first movement restricting means. In addition, when the movable block is provided at each of the first position and the second position by the first movement restricting means, a gap is provided between the side surface of the movable block and the pole piece. The first movement restricting means only needs to be able to withstand a force of 1.2 kgf in a direction perpendicular to the direction of movement of the movable block. If it cannot withstand a force of 1.2 kgf, the stop position of the movable block or the attitude of the light reflector may fluctuate, and the input loss may increase during use. Also, when the optical switch is placed vertically, horizontally, obliquely, or upside down, the fluctuation of insertion loss increases. By withstanding a force of 1.2 K gf or more in the direction perpendicular to the direction of movement of the movable block, insertion loss can be kept small even if the optical switch is in various postures.

It should be noted that ceramics containing 90% alumina instead of non-magnetic cemented carbide were used for guidance. You can make Dobin.

The movable block of the self-holding optical switch of the present invention has second movement restricting means for substantially inhibiting the movement of the movable block of the input optical fiber toward the optical axis. In the self-holding optical switch 100 of the first embodiment, as the second movement restricting means, a connection is made between the support block 19 1 fixed to the substrate 1 15 and the movable block 13 4. Two optical fibers are used. Two V-grooves were formed on the bottom surface of the support block 191, and one end of each of two optical fibers (12.5 // m diameter) 1 86 was bonded and fixed to each V-groove. . Two V-grooves are formed at 500 μm intervals between the two guide holes 18 3 on the surface of the movable block 13 4 where the guide holes 18 3 are formed, and two optical fibers are formed. The other end of each one of 186 was adhesively fixed to each of the V-grooves. When the optical fiber 186 is bonded and fixed to the V-groove formed in each of the support block and the movable block, the optical fiber is held down by a cover glass and fixed. The movable block 1 3 4 is easily moved between the first and second positions because the movable block 1 3 4 is maintained at a fixed distance from the support block 19 1 by the optical fiber 1 8 6 However, the optical fiber is not substantially moved in the length direction of the optical fiber 186, that is, in the direction of the fixed block 126 and the direction of the soft magnetic material block 132. The force against the movable block in the direction of the movement connecting the first position and the second position by the second movement restricting means shall be _{0.96 §} £ or more and 1.12 gf or less. Is preferred. The elasticity of the optical fiber 186 produces a force that opposes the movable block 134 in the direction of the movement. The force that holds the movable block in the first position or the second position is determined by the magnetic attraction generated by the permanent magnet 164 of the electromagnetic actuator and the optical fiber at the first position or the second position. This is the size obtained by subtracting the elastic force of 6. The movable block switches when the magnetic attraction force caused by the current flowing through the coil member of the electromagnetic actuator exceeds the force held at the stop position of the movable block. For this reason, if the elastic force of the optical fiber 186 is too strong, the holding force decreases. If the elastic force is too weak, the current that needs to flow through the coil member of the electromagnetic actuator to switch the movable block increases. If the elastic force of the optical fiber at the stop position of the movable block is less than 0.96 gf, the current required for switching increases, and heat is generated in the electromagnetic actuator. On the other hand, If the elastic force of the eye bar 186 exceeds 1.12 gf, the power to hold the movable block will be insufficient, and the optical switch will not be able to withstand impact tests.

 The force by which the second movement restricting means holds the movable block in the optical axis direction of the input optical fiber need only be 32 gf or more. If the holding force in the optical axis direction is less than 32 gf, the movable block will be attracted to the fixed block and the soft magnetic block, and the distance between the fixed block and the movable block will change, and the insertion loss will change. The insertion loss is stable when the holding force in the optical axis direction at the stop position of the movable block is 32 gf or more. With the first movement restricting means, it is possible to prevent a change in the stop position of the movable block, that is, the V-groove mirror, and a change in the posture of the movable block, that is, the V-groove mirror, with respect to the fixed block, that is, the input / output optical fiber. Thus, the optical signal emitted from the open end of the input optical fiber can be coupled to the output optical fiber with an input loss of less than 0.5 dB.

 With the first movement restricting means, the fluctuation of the stop position at the first position and the second position of the V-groove mirror can be made less than 0.5 / m. Since the variation of the stop position of the V-groove mirror can be made less than 0.5 μπι, the insertion loss becomes less than 0.5 dB when an input / output optical fiber having a core diameter of 10 m is used. Further, the inclination and posture of the V-groove mirror surface with respect to one optical axis of the input and output optical fibers can be made less than 0.05 ° by the first movement restricting means. It can be less than 5 dB. '

 Since the distance between the movable block and the fixed block and the distance between the movable block and the soft magnetic block are maintained by the second movement restricting means, the movement of the movable block becomes smooth. Furthermore, since the distance between the open end of the input / output optical fiber and the V-groove mirror is kept constant, the coupling length between the open ends of the input / output optical fiber, that is, the microphone lens of the microlens array 128. Can be kept at less than 80 μm, and the variation of the input loss can be made less than 0.5 dB. In this embodiment, an optical fiber is used as the second movement restricting means. However, another material having flexibility in the bending direction and rigidity in the optical axis direction, for example, glass fiber or plastic fiber is used. And so on.

FIG. 7 shows a modification of the posture when the optical switch is installed. Example 1 Fifty optical switches 100 were fabricated and placed flat as shown in Fig. 7 (A), and the insertion loss was measured. The insertion loss of the 50 optical switches was 0.08-0. It was distributed at 46 dB, and the average was 0.26 dB. FIG. 8 shows a frequency distribution graph of the insertion loss of these 50 self-holding optical switches 10.0. Comparing this frequency distribution graph of insertion loss with the frequency distribution graph of insertion loss of a conventional self-holding optical switch using a V-groove mirror (Fig. 12), it is clear that the self-holding type of Example 1 was used. The insertion loss of the optical switch is reduced. Since the self-holding optical switch of the first embodiment has the first movement restricting means and the second movement restricting means, the insertion loss of the optical switch can be reduced. Next, as shown in Fig. 7 (B), the insertion loss of the same 50 optical switches measured vertically is 0.09 to 0.47 dB (average 0.27 dB). there were. As shown in Fig. 7 (C), the insertion loss measured with the optical switch upside down was 0.08 to 0.47 dB (average 0.26 dB). As shown in FIG. 7 (D), the insertion loss measured with the optical switch placed obliquely was 0.07 to 0.48 dB (average 0.27 dB). As shown in Fig. 7 (E), with the optical switch placed on its side, the measured insertion loss was 0.08 to 0.47 dB (average 0.27 dB). Changing the placement of the optical switch did not increase the variation in insertion loss.

 Furthermore, since the self-holding optical switch 100 of the first embodiment has the input and output optical fibers 122, 122a and 122b on the same side as viewed from the electromagnetic actuator 150, 2 Omm The optical switch mechanism could be accommodated in the length 110 of the housing. The length of the housing can be reduced to 70% compared to the optical fiber one-drive type optical switch 300 described earlier.

Example 2

Second Embodiment FIG. 9 is a vertical sectional view showing a self-holding optical switch 200 according to a second embodiment of the present invention. The same parts as those of the self-holding optical switch of the first embodiment are denoted by the same reference numerals. This is a 2 × 4 optical switch in which a combination of an input optical fiber 1 and an output optical fiber 1 2 2 a and a 1 2 2 b is attached to a fixed block 226 so as to be vertically arranged in two stages. The fixing block 226 has six through-holes in three rows and two rows vertically at an interval of 250 μπι, and the input and output fibers 121, 122a, and 122 are bonded and fixed to each through-hole. did. Also, The opening lens array 228 is provided with six rows of three rows horizontally and two rows vertically at an interval of 250 / X m. The microphone aperture lens array 228 was bonded and fixed so that the center of each optical fiber coincided with the center of each lens. Other configurations were the same as in the first embodiment. By arranging the combination of the input and output optical fibers 121, 122a, and 122b in two upper and lower stages, a 2 × 4 optical switch having the same dimensions as in the first embodiment was obtained. In other words, two 1X2 optical switches that simultaneously switch two 1X2 optical switches are realized.

 Fifty self-holding optical switches of Example 2 were manufactured, and the insertion loss was measured. As shown in Fig. 7 (A), the insertion loss measured with the optical switch laid flat was 0.09 to 0.48 dB (0.28 dB on average). Since the self-holding optical switch of the second embodiment has the first movement restricting means and the second movement restricting means, the difference in insertion loss between the optical switches can be reduced. Also, as shown in Fig. 7 (B), the insertion loss measured with the optical switch placed vertically is 0.09 to 0.47 dB (average 0.27 dB), and the insertion loss in Fig. 7 (C) is The insertion loss measured with the optical switch upside down is 0.08 to 0.49 dB (average 28 dB), and the insertion loss measured with the optical switch inclined as shown in Fig. 7 (D). The loss is 0.09 to 0.47 dB (average 27 dB), and the insertion loss measured with the optical switch placed horizontally as shown in Fig. 7 (E) is 0.08 to 0.48 dB (average 0 dB). 27 dB), the variation of the insertion loss did not increase even if the position of the optical switch, that is, the posture was changed. Although not described in detail, instead of the fixed block 226 having six through holes, an optical switch having a structure in which the V-groove blocks used in the previous embodiment are stacked in two stages was also manufactured. Similarly, a low-loss optical switch was obtained. Industrial applicability

 According to the self-holding optical switch of the present invention, the variation in insertion loss is as small as 0.5 dB or less, and the length direction can be reduced by 30% as compared with the conventional fiber-driven optical switch.

Claims

The scope of the claims 1. An input optical fiber with an open end, A first output optical fiber having an open end, A second output optical fiber having an open end, A fixed block that arranges the open ends of the input optical fiber, the first output optical fiber, and the second output optical fiber, and holds the optical fibers in parallel in a plane; At least a portion is made of a soft magnetic material, has an optical reflector provided opposite to the fixed block, and the optical reflector is connected between the open end of the input optical fiber and the open end of the first output optical fiber. Between a first position for coupling an optical signal between the first position and an optical reflector whose optical reflector couples an optical signal between the open end of the input optical fiber and the open end of the second output optical fiber. A movable block capable of moving the movable block in a plane parallel to the plane, the movable block being reciprocated between a first position and a second position, and a movable block between the first position and the second position. In a self-holding optical switch having an electromagnetic actuator for holding and holding the The movable block includes a first movement restricting unit that restricts a movement of the movable block between a first position and a second position in the plane parallel to the plane on which the optical fiber is provided. And a second movement restricting means for substantially prohibiting the movement of the movable block in the optical axis direction of the input optical fiber. 2. The electromagnetic actuator is A first yoke with a first paw piece, A second yoke with a second pole piece, The first and second pole pieces sandwich the movable block so that they can reciprocate between these two pole pieces. A magnetic flux is emitted to the first and second yokes and the movable block, and a first magnetic path is formed by the first yoke and the movable block. And a permanent magnet constituting a second magnetic path, A first coil member wound around the first yoke for adjusting magnetic flux between the movable block and the first pole piece; and 2. The self-holding light according to claim 1, further comprising a second coil member wound around the second yoke for adjusting magnetic flux between the movable block and the second pole piece. Switch. 3. The first movement restricting means comprises a guide bin provided on one of the opposing surfaces of the movable block and the fixed block, and a guide provided on the other surface, The self-holding type according to claim 1, wherein the second movement restricting means has flexibility in a plane in which the movable block can move, and has rigidity in an optical axis direction of the input optical fiber. Light switch. 4. The first movement restricting means comprises a guide bin provided on one of the opposing surfaces of the movable block and the fixed block, and a guide provided on the other surface, The self-holding type according to claim 2, wherein the second movement restricting means has flexibility in a plane in which the movable block can move, and has rigidity in an optical axis direction of the input optical fiber. Light switch.