WO2004005997A1

WO2004005997A1 - Cantilever, light beam control device, variable light attenuator, and variable light attenuating device

Info

Publication number: WO2004005997A1
Application number: PCT/JP2003/008650
Authority: WO
Inventors: Katsuhiko Kurumada; Masatoshi Kanaya; Toshiaki Tamamura; Keiichi Akagawa; Yoshihiko Suzuki; Tohru Ishizuya; Junji Suzuki
Original assignee: Ntt Electronics Corporation; Nikon Corporation
Priority date: 2002-07-09
Filing date: 2003-07-08
Publication date: 2004-01-15
Also published as: AU2003281408A1; AU2003281408A8

Abstract

A cantilever having an excellent controllability, a light beam control device, a variable light attenuator, and a variable light attenuating device, wherein the cantilever (59) moving an optical member (54) in vertical direction relative to the optical paths of light guiding paths (51) and (52) supports the optical member (54) by an insulation film, moves the optical member (54) by a voltage or a current applied to electric wiring (60a) disposed on the insulation film, and prevents a difference in extension from occurring on both surfaces of the insulation film by using a material (60b) having the same coefficient of linear expansion as the electric wiring (60a).

Description

Specification

Technical field of cantilever, light beam adjusting device, variable optical attenuator, and variable optical attenuator

The present invention relates to a cantilever, a light beam adjusting device, a variable optical attenuator, and a variable optical attenuator, and more particularly, to a cantilever using MEMS (Micro Electro Mechanical Systems) technology, a light beam adjusting device, a variable optical attenuator, and And a variable optical attenuator. Background art

Light beam adjusting devices such as variable optical attenuators (attenuators) and optical switches are used in, for example, optical communications. Here, the background art is explained using a variable optical attenuator as an example. There are several types of variable optical attenuators. For example, US Pat. No. 6,173,105 discloses a variable optical attenuator of the type using MEMS technology.

This variable optical attenuator is shown in FIGS. FIG. 15 is a side view showing the main part, and FIG. 16 is a plan view showing the main part. This variable optical attenuator uses a MEMS device 110 (Fig. 15).

The MEMS device 110 has a shirt 114. The shutter 114 can be inserted into the gap 113 between the ends 11A and 11A of the optical fibers 11 and 11 arranged opposite to each other. The shirt 114 is connected to the tip of the cantilever 1 18 (FIGS. 15 and 16).

The cantilever 118 is connected to a flexure section 117 that generates a panel force. The flexure section 117 includes flexible arms 122A and 122B (FIG. 16). The enlarged portions 125A and 125B at one ends of the flexible arms 122A and 122B are connected to the columns 12OA and 120B, respectively. The other ends of the flexible arms 122A and 122B are connected to a top plate 116 as a movable electrode.

Further, the bottom plate as a fixed electrode is opposed to the top plate 116. (See FIG. 15) Force S, located on the substrate 119. Further, a reinforcing portion 123 (FIG. 16) is provided between the flexible arms 122 A and 122 B, and a cantilever 118 extends from the reinforcing portion 123.

In this variable optical attenuator, when no voltage is applied between the top plate 116 and the bottom plate 115, as shown in FIG. Since the optical path between the optical fibers 111 and 112 is not blocked, the amount of light transmitted from the optical fiber 111 to the optical fiber 112 becomes maximum.

—When a voltage is applied between the top plate 1 16 and the bottom plate 1 15, both plates 1 16 and 1 15 are attracted by the electrostatic force generated between them, and the top plate 1 16 moves downward. Move to. When the top plate 1 16 descends, the shutter 114 moves upward with the cantilever 118 as the fulcrum of the columns 12 O A and 120 B (lever structure). Then, the shirt 1114 advances into the gap 113 between the optical fibers 111 and 112.

At this time, the shutter 114 stops at a position where the electrostatic force between the plates 116 and 115 and the panel force of the flexure unit 117 balance. The amount by which the optical path between the optical fibers 1 1 1 and 1 1 2 is blocked depends on the stop position of the shirt 1 1 and the amount of light transmitted from the optical fiber 1 1 to the optical fiber 1 1 Decay.

Thus, in the conventional variable optical attenuator (Fig. 15 and Fig. 16), the electrostatic force between the plates 1 16 and 1 15 is used to apply the voltage between the plates 1 16 and 1 15 By changing the applied voltage, the stop position of the shirt 114 can be changed, thereby controlling the amount of attenuation.

However, in the above-mentioned conventional variable optical attenuator, since the cantilever 118 is distorted due to the fluctuation of the ambient temperature, and the stop position of the shirt 114 is fluctuated, it is difficult to control the position with high accuracy.

Further, in the above-mentioned conventional variable optical attenuator, a high voltage is required because the shutter 114 is moved by using an electrostatic force between the plates 116 and 115, and both plates are required. There was no straight line i in the relationship between the voltage value between 1 16 and 1 15 and the interval (stop position of the shirt 1 114), which was one of the causes of difficulty in control.

Furthermore, these problems are not limited to variable optical attenuators, but also light beams such as optical switches. The same can occur with a regulating device. Disclosure of the invention

An object of the present invention is to provide a cantilever, a light beam adjusting device, a variable optical attenuator, and a variable optical attenuator excellent in controllability.

A cantilever according to the present invention is a cantilever for moving an optical member, which can be inserted into a groove provided so as to traverse a part or the whole of an optical path, in a direction perpendicular to the optical path, wherein the optical member is supported by an insulating thin film. The optical member is moved by a voltage or a current applied to the electric wiring provided on the insulating thin film, and is stretched on both surfaces of the insulating thin film using a material having a coefficient of linear expansion equal to that of the electric wiring. It is designed to make no difference.

In this cantilever, since both surfaces of the insulating thin film extend equally with changes in the ambient temperature, there is no distortion. Therefore, the optical member can be operated stably, and the controllability is excellent.

Preferably, in the cantilever of the present invention, a dummy electric wiring is provided on the surface of the insulating thin film opposite to the surface on which the electric wiring is provided so as to be plane-symmetric with respect to the electric wiring. It is arranged.

Preferably, the cantilever of the present invention is arranged such that, of the two surfaces of the insulating thin film, a dummy electric wiring is provided on a surface opposite to a surface on which the electric wiring is provided so as to be point-symmetric with respect to the electric wiring. Is provided.

Preferably, in the cantilever of the present invention, an insulating material having a linear expansion coefficient equal to that of the electric wiring is laminated on a surface of the insulating thin film opposite to a surface on which the electric wiring is provided, of the two surfaces. is there.

An optical beam adjustment device of the present invention includes: an optical waveguide disposed on a substrate; a groove provided so as to traverse part or all of an optical path of the optical waveguide; and an optical member insertable into the groove. A cantilever that supports the optical member with an insulating thin film and moves the optical member in a direction perpendicular to the optical path, wherein the cantilever is a voltage or a current applied to an electric wiring provided on the insulating thin film. The optical member is moved by using the material having the same linear expansion coefficient as that of the electric wiring, and the insulating thin film is used. Are constructed so as not to cause a difference in extension between both sides.

In this light beam adjustment device, since the both surfaces of the insulating thin film of the cantilever are equally stretched with respect to the fluctuation of the ambient temperature and the cantilever is not distorted, the adjustment of the light beam crossing the groove can be performed more stably by the position of the optical member. The result is excellent controllability. Another optical beam adjusting device according to the present invention includes: an optical fiber disposed on a substrate; a slit provided so as to traverse a part or all of an optical path of the optical fiber; and an optical member insertable into the slit. And a force cantilever for supporting the optical member with an insulating thin film and moving the optical member in a direction perpendicular to the optical path, wherein the cantilever is applied to electric wiring provided on the insulating thin film. The optical member is moved by a voltage or a current, and is made of a material having a coefficient of linear expansion equal to that of the electric wiring so as not to cause a difference in extension between both surfaces of the insulating thin film. In this light beam adjustment device, both sides of the insulating thin film of the cantilever extend equally to changes in the ambient temperature, and the cantilever does not distort, so that the adjustment of the light beam across the slit can be performed more stably according to the position of the optical member. And excellent controllability.

Preferably, in the light beam adjusting device according to the present invention, the cantilever has a surface symmetrical with respect to the electric wiring on a surface of the insulating thin film opposite to a surface on which the electric wiring is provided. In this case, dummy electric wiring is provided.

Preferably, in the light beam adjusting device of the present invention, the cantilever has a point symmetry with respect to the electric wiring on a surface of the insulating thin film opposite to a surface on which the electric wiring is provided. In this case, a dummy electric wiring is provided.

Preferably, in the light beam adjusting device according to the present invention, the cantilever has a linear expansion coefficient equal to that of the electric wiring on a surface of the insulating thin film opposite to a surface on which the electric wiring is provided. However, an insulating material is laminated.

The variable optical attenuator of the present invention includes: an optical waveguide disposed on a substrate; a groove provided to traverse the optical path of the optical waveguide; an optical member insertable into the groove; and an insulating thin film. A cantilever that supports an optical member, moves the optical member in a direction perpendicular to the optical path, and moves the optical member so that an amount of attenuation of light that traverses the groove becomes a desired value. Applied to electrical wiring arranged on insulating thin film The optical member is moved by the applied voltage or current, and the electric wiring has a surface opposite to the insulating thin film covered with a material having a coefficient of linear expansion equal to that of the insulating thin film.

In this variable optical attenuator, since both surfaces of the electric wiring of the cantilever extend equally to changes in the ambient temperature and the cantilever does not distort, a desired amount of attenuation can be stably obtained depending on the position of the optical member. It is excellent in controllability.

Preferably, in the variable optical attenuator according to the present invention, the opposite surface of the electric wiring is covered with a material having the same linear expansion coefficient and the same film thickness as the insulating thin film. Another variable optical attenuator of the present invention includes: an optical waveguide disposed on a substrate; a groove provided to traverse an optical path of the optical waveguide; an optical member insertable into the groove; and the optical member. A cantilever that moves the optical member in a direction perpendicular to the optical path, and moves the optical member so that the amount of attenuation of light that traverses the groove becomes a desired value. A free end movable with respect to the optical member, supporting the optical member at the free end, and moving the free end by a voltage or a current applied to electric wiring provided on the force cantilever; The electrical wiring is provided such that a panel force acts according to the position of the end, and the electric wiring has a current path arranged in a magnetic field to generate a Lorentz force against the panel force by the voltage or the current. Rumo It is.

In this variable optical attenuator, the optical member can be moved by a low voltage or current, and the relationship between the value of the voltage or current and the position of the optical member becomes linear. Therefore, a desired amount of attenuation can be stably obtained depending on the position of the optical member, and the controllability is excellent. -Preferably, in the variable optical attenuator of the present invention, the cantilever supports the optical member by a thin film.

Preferably, in the variable optical attenuator of the present invention, the cantilever supports the optical member with an insulating thin film, the electric wiring is provided on the insulating thin film, and the electric wiring and the coefficient of linear expansion are different from each other. The same thin film is used so as not to cause a difference in extension between both surfaces of the insulating thin film.

In this variable optical attenuator, the optical member can be moved by a low voltage or current. In addition to the fact that the relationship between the value of the voltage or current and the position of the optical member becomes linear, both surfaces of the insulating thin film of the cantilever extend equally with respect to the fluctuation of the ambient temperature, and Does not distort. Therefore, the controllability is further improved. Preferably, in the variable optical attenuator of the present invention, the cantilever supports the optical member by an insulating thin film, the electric wiring is provided on the insulating thin film, and the electric wiring is the insulating thin film. The surface opposite to the above is covered with a material having the same coefficient of linear expansion as the insulating thin film.

In this variable optical attenuator, the optical member can be moved by a low voltage or current, and the relationship between the value of the voltage or current and the position of the optical member becomes linear. Both sides of the electrical wiring stretch equally with changes in ambient temperature, and the cantilever does not distort. Therefore, the controllability is further improved. Preferably, in the variable optical attenuator according to the present invention, the opposite surface of the electric wiring is covered with a material having the same linear expansion coefficient and the same film thickness as the insulating thin film. A variable optical attenuator according to the present invention includes the above variable optical attenuator, and a magnetic field generating unit that generates the magnetic field.

Preferably, the variable optical attenuator of the present invention includes a control unit that controls at least one of the current in the current path and the magnetic field. BRIEF DESCRIPTION OF THE FIGURES

FIG. 1 is a diagram showing a configuration of a light beam adjusting device.

FIG. 2 is a diagram illustrating a configuration of the force cantilever of the first embodiment.

FIG. 3 is a diagram showing a configuration of the force cantilever of the second embodiment.

FIG. 4 is a diagram showing a configuration of the force cantilever of the third embodiment.

FIG. 5 is a diagram illustrating a configuration of a cantilever of a comparative example.

FIG. 6 is a schematic plan view schematically showing the variable optical attenuator of the fourth embodiment. FIG. 7 is a cross-sectional view along X1-X2 of FIG. 6, showing a predetermined operation state.

FIG. 8 is a cross-sectional view along X1-X2 of FIG. 6, showing another operation state.

FIG. 9 is a cross-sectional view along X1-X2 of FIG. 6, showing still another operation state.

FIG. 10 is a diagram showing a model of the variable optical attenuator shown in FIGS. 6 to 9. FIG. 11 is a diagram showing characteristics calculated based on the model shown in FIG.

FIG. 12 is a diagram illustrating a model of a variable optical attenuator according to a comparative example.

FIG. 13 is a diagram showing characteristics calculated based on the model shown in FIG. FIG. 14 is a schematic plan view schematically showing a part of the variable optical attenuator of the fifth embodiment.

FIG. 15 is a side view showing a main part of a conventional variable optical attenuator.

FIG. 16 is a plan view showing a main part of the conventional variable optical attenuator shown in FIG. BEST MODE FOR CARRYING OUT THE INVENTION

Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.

(First Embodiment)

FIG. 1 shows a configuration of a waveguide type light beam adjusting device according to a first embodiment of the present invention. FIG. 1A is an enlarged top view showing a groove 53 portion. The groove 53 is provided at the intersection of the two optical waveguides 51 and 52 so as to cross the optical paths of the optical waveguides 51 and 52. In the groove 53, there is a mirror 54 mounted on a cantilever (not shown).

(Optical member) can be inserted. In the present embodiment, as the optical waveguides 51 and 52, quartz-based waveguides having a core / clad relative refractive index difference Δ = 0.45% and a rectangular core having a cross-sectional dimension of 7 μππ were used.

FIG. 1 (b) is a cross-sectional view taken along line A-Α of FIG. 1 (a). A lower cladding layer 56 and a core layer 57 are sequentially deposited on a substrate 55, and optical waveguides 51 and 52 are formed by photolithography. The lower clad layer 56 and the core layer 57 are covered with the upper clad layer 58 to complete the optical waveguides 51 and 52. The groove 53 is provided by removing a part of the core layer 57 and the lower clad layer 56.

Above the groove 53, a cantilever 59 is installed. A mirror 54 is attached to the tip of the cantilever 59. The cantilever 59 is made of a silicon nitride thin film (insulating thin film), and the mirror 54 is supported by the silicon nitride thin film. The cantilever 59 is a cantilever having a fixed end (not shown) on the right side in FIG. 1 and a free end on which the mirror 54 is fixed. Further, the power cantilever 59 of the first embodiment is provided with conductive wiring patterns 60a and 60b on both surfaces thereof. The configuration of the wiring patterns 60a and 60b is as shown in FIG. FIG. 2A is a bottom view of the cantilever 59. FIG. 2B is a cross-sectional view along the line X--X '. FIG. 2C is a sectional view taken along the line Y-Y '.

A mirror 54 is fixed to the lower surface of the cantilever 59, and the original wiring pattern 6

0a (electrical wiring) is provided. On the upper surface of the cantilever 59, a dummy wiring pattern 60b is provided. The original wiring pattern 60a and the dummy wiring pattern 60b are made of a material having the same linear expansion coefficient, and are provided so as to have mirror symmetry with respect to the symmetry line Z-Z '.

Here, the silicon nitride thin film used as the material of the cantilever 59 has advantages that it has mechanical strength and that the wiring patterns 60a and 60b can be insulated from each other. For the wiring patterns 60a and 60b, for example, aluminum, which is a highly conductive material, is used as the wiring material.

As described above, even when the power fulcrum 59 of the first embodiment has a structure in which two materials having different linear expansion coefficients are laminated, the film has the same linear expansion coefficient on both the upper surface and the lower surface of the silicon nitride thin film. Since the wiring patterns 60a and 60b having the same thickness are provided, the upper surface and the lower surface of the silicon nitride thin film extend equally with respect to the fluctuation of the ambient temperature. For this reason, the upward warpage moment and the downward warpage moment become equal, and no distortion such as warpage or deformation occurs.

Here, the film thicknesses were made equal. However, the present invention is not limited to this. H Even if the thicknesses are not equal, the stress is reduced as compared with the conventional configuration, so that there is an effect that distortion such as warpage or deformation is reduced.

In this cantilever 59, by applying an applied current (or an applied voltage) to the original wiring pattern 60a, the free end of the cantilever 59 is caused by an electrostatic force between a movable electrode and a fixed electrode (not shown). By moving the mirror up and down, the mirror 54 can be moved in the depth direction of the groove 53 (that is, in the direction perpendicular to the optical paths of the optical waveguides 51 and 52). By controlling the applied current (or applied voltage), the stop position of the mirror 54 can be changed.

As described above, both sides of the silicon nitride thin film of cantilever 59 change in ambient temperature. , The mirror 54 can be operated stably, and a cantilever 59 with excellent controllability can be obtained. Further, the position of the mirror 54 can stably adjust the light beam that crosses the groove 53, so that a light beam adjusting device with excellent controllability can be obtained.

Therefore, it is not necessary to mount the heat conversion element required for temperature control on the light beam adjustment device or to control the temperature in the room where the light beam adjustment device is installed, and to reduce the size of the device and save labor in operation. be able to.

When operating the light beam adjusting device as an optical switch, the traveling direction of the light beam may be switched according to the position of the mirror 54 (switching operation). For example, in the case of a light beam incident from the optical waveguide 5 lb (FIG. 1), this light beam is

An optical waveguide that is cut off at 4 and is reflected toward 2 b

What is necessary is just to realize the transmission state which advances to 51a.

The dimension of the mirror 54 is desirably small from the viewpoint of the time required for entering or retracting the groove 53, that is, the switching speed. On the other hand, a certain size is required to completely block the spread of propagating light seeping into the cladding region. In the quartz-based waveguide described above, the minimum size of the mirror 54 that blocks the light beam is

It is 40 / im x 40 m. The vertical movement of the mirror 54 is 50 m in consideration of the setting error. At this time, the arm length of cantilever 5 9 is mirror 5

Assuming that the movement width of 4 is 10 times or more, it is 500 / m.

If m parallel optical waveguides and n parallel optical waveguides are crossed and a light beam adjusting device is arranged at each crossing position, a matrix type optical switch of m X n can be obtained. Can be configured.

In addition, depending on the stop position of the mirror 54, a part of the light beam incident from the optical waveguide 51b may be cut off, and the remaining light may be transmitted, so that the attenuation of light crossing the groove 53 may be varied. A light beam adjustment device (attenuator) that can be used. That is, a desired amount of attenuation can be stably obtained by the position of the mirror 54, and an attenuator excellent in controllability can be obtained.

(Second embodiment)

Next, a cantilever 69 (FIG. 3) of the second embodiment of the present invention will be described. The cantilever 69 of the second embodiment is also made of a silicon nitride thin film.

In the cantilever 69 of the second embodiment, conductive wiring patterns 70a and 70b are provided on both surfaces in an arrangement as shown in FIG. FIG. 3A is a bottom view of the cantilever 69. FIG. 3B is a cross-sectional view along the line X--X '. FIG. 3C is a sectional view taken along the line Y—Y ′.

A mirror 54 is fixed to the lower surface of the cantilever 69, and an original wiring pattern 70a is provided. On the upper surface of the cantilever 69, a dummy wiring pattern 70b is provided. The original wiring pattern 70 a and the dummy wiring pattern 70 b are made of a material having the same coefficient of linear expansion and the same film thickness, and are provided so as to be point-symmetric with respect to the point P.

Therefore, in the cantilever 69 of the second embodiment, the twist occurs in the Y—Y direction with respect to the fluctuation of the ambient temperature, but the upper surface and the lower surface of the silicon nitride thin film extend equally. Therefore, the upward warpage moment and the downward warpage moment become equal in the vertical movement direction of the mirror 54, and no distortion such as warpage or deformation occurs.

Here, the film thicknesses were made equal. However, the present invention is not limited to this. Even if the film thicknesses are not equal, the stress is reduced as compared with the conventional configuration, and thus there is an effect that distortion such as warpage or deformation is reduced.

In the first and second embodiments described above, the wiring patterns 60a, 60b are provided on both surfaces of the silicon nitride thin film of the cantilever 59, and the wiring patterns 70a, 70b are provided on both surfaces of the cantilever 69. 0b was provided to prevent a difference in extension. However, for example, a plurality of layers of insulating materials such as silicon nitride having different hardness and temperature coefficient may be laminated to form a force-chinch lever so that no difference in extension occurs between both surfaces. Similarly, cantilevers can be made by combining different materials or shapes and can be mirror symmetric about the symmetry line Z-Z 'or point symmetric about the point P.

(Third embodiment)

Next, a cantilever 79 (FIG. 4) according to a third embodiment of the present invention will be described. The cantilever 79 of the third embodiment is also made of a silicon nitride thin film. FIG. 4 is a sectional view of the cantilever 79. The mirror 54 is fixed to the tip of the silicon nitride thin film of the cantilever 79. As shown in FIG. 4, in the third embodiment, the wiring pattern 80 is provided only on the upper surface of the cantilever 79. Also, a second silicon nitride thin film 81 is provided so as to cover the upper surface of wiring pattern 80 (the surface opposite to cantilever 79). The coefficient of linear expansion of the silicon nitride thin film 81 is equal to the thickness of the silicon nitride thin film of the cantilever 79.

As described above, in the cantilever 79 of the third embodiment, since both surfaces of the wiring pattern 80 are sandwiched by the silicon nitride thin films having the same linear expansion coefficient, both surfaces of the wiring pattern 80 extend equally with respect to the fluctuation of the ambient temperature. I do. Therefore, the upward warpage moment and the downward warpage moment become equal, and no distortion such as warpage or deformation occurs. Here, the film thicknesses were made equal. However, the present invention is not limited to this. Even if the film thicknesses are not equal, the stress is reduced as compared with the conventional configuration, and thus there is an effect that distortion such as warpage or deformation is reduced.

In the third embodiment, the wiring pattern 80 is provided only on the upper surface of the cantilever 79, but the present invention is not limited to this. The same effect can be obtained even when the wiring pattern is provided only on the lower surface of the cantilever 79 and the second silicon nitride thin film is provided so as to cover the lower surface of this wiring pattern (the surface opposite to the cantilever 79). be able to.

Here, the cantilever 89 of the comparative example shown in FIG. 5 will be briefly described, and the result of comparison with the present embodiment will be described.

The cantilever 89 of the comparative example is also made of a silicon nitride thin film. FIG. 5 is a sectional view of Cantilever 89. A mirror 84 is fixed to the tip of the silicon nitride thin film of the cantilever 89. The cantilever 89 of the comparative example is provided with a wiring pattern 90 only on the lower surface thereof. The wiring pattern 90 is made of aluminum. Furthermore, the arm length of the cantilever 89 is 500 μπι, and the thickness is Ιμπι. The thickness of the wiring pattern 90 is also 1 Aim. Due to the difference in the coefficient of linear expansion between the cantilever 89 and the wiring pattern 90, a difference in extension of about 20 X 10-6 / deg occurs near normal temperature. When calculating the warpage of the tip of the cantilever 89, a warp of about 25 m is generated near normal temperature due to a temperature change of 10 ° C.

Also, a mirror 84 was inserted into the groove (not shown), and the light beam crossing the groove was cut off. A 3 dB attenuation was caused in the state. At this time, when the set position of the mirror 84 changes by 0.1 mm, the attenuation changes by ± 0.1 dB. Therefore, around room temperature,

A temperature change of 1 ° C causes a warpage of about 2.5, so the attenuation changes by approximately ± I dB.

On the other hand, also in the first embodiment shown in FIG. 1 (b), the cantilever 59 was made of a silicon nitride thin film, and the wiring patterns 60a and 60b were made of aluminum. The arm length of the cantilever 59 is 500 im and the thickness is 1 μπι. The thickness of the wiring patterns 60a and 60b was 1πι, and the patterns shown in FIG. 3 were provided. At this time, near the room temperature, there is almost no difference in extension, so that there is no warping that changes the attenuation. In the light beam adjusting devices of the first to third embodiments described above, the quartz-based waveguide including the core layer and the clad layer is used, but the present invention is not limited to this. Instead of the silica-based waveguide, for example, a structure in which optical fibers are arranged on a substrate can be used.

Specifically, V-shaped grooves for mounting optical fibers are formed on a silicon substrate by etching or cutting, and optical fibers are arranged. Also, slits are provided so as to cross the optical path of the optical fiber. Glass, ceramics, resin, and the like can be used for the substrate, and a light beam adjusting device can be manufactured at a lower cost than a quartz-based waveguide.

Also, the cantilever according to the present embodiment is not limited to a cantilever supported at one end, but may be a two-point support beam supporting both ends or a cross beam supporting four points by fixing a mirror at the center. Can also be applied.

Furthermore, in the first to third embodiments described above, the cantilevers 59, 69,

Although the mirror 54 is supported on the lower surface of the 79, the present invention can be applied to a cantilever supporting the mirror 54 on the upper surface.

In the first to third embodiments described above, the forceps levers 59, 69, 7

Although 9 was driven by electrostatic force, it can also be driven by Lorentz force. The details of the drive by the Lorentz force will be described in the following fourth embodiment.

(Fourth embodiment)

FIG. 6 is a schematic plan view schematically showing a variable optical attenuator according to a fourth embodiment of the present invention. is there. In Fig. 6, the lines that should be hidden lines (broken lines) are also indicated by solid lines to clarify the positional relationship between the elements in plan view. 7 to 9 show respective operation states, and are schematic cross-sectional views along the line X1-X2 in FIG.

For convenience of explanation, X-axis, Y-axis and Z-axis which are orthogonal to each other are defined as shown in Figs. The surface of the substrate 31 of the variable optical attenuator 1 described later is parallel to the XY plane. In the Z-axis direction, the direction of the arrow is called + Z direction or + Z side, and the opposite direction is called one Z direction or one Z side, and the same applies to the X axis direction and the Y axis direction. The + side in the Z-axis direction may be referred to as the upper side, and one side in the Z-axis direction may be referred to as the lower side.

As shown in FIGS. 6 to 9, the variable optical attenuator according to the fourth embodiment includes a variable optical attenuator 1 and a magnet 2 provided below the variable optical attenuator 1 (shown in FIGS. 7 to 9). ) And a control unit 3 (shown in FIG. 6). The magnet 2 is a magnetic field generation unit that generates a magnetic field for the variable optical attenuator 1. The control unit 3 responds to an external attenuation command signal and supplies a control signal (current signal in this embodiment) for realizing the attenuation indicated by the attenuation command signal to the variable optical attenuator 1. .

The variable optical attenuator 1 includes a support 11 made of ceramic or the like, an actuator 13 disposed above the support 11, an optical waveguide substrate 12 disposed above the actuator 13, and an actuator 13 (optical member).

The optical waveguide substrate 12 (FIG. 6) is provided so as to traverse the optical waveguide 21 for guiding the incident light, the optical waveguide 22 for guiding the output light after attenuation, and the optical paths of the optical waveguides 21 and 22. Groove 23. The shirt 14 can be inserted into the groove 23. The groove 23 is a recess for receiving the shutter 14 and has a width of, for example, about 10 × m.

As shown in FIG. 6, the output end of the optical waveguide 21 and the input end of the optical waveguide 22 are exposed on opposing side surfaces of the groove 23 so as to face each other with a space therebetween. The incident end of the optical waveguide 21 is exposed on the end face of the optical waveguide substrate 12. An optical fiber 15 for guiding incident light is connected to the incident end. Similarly, the emission end of the optical waveguide 22 is exposed on the end face of the optical waveguide substrate 12. An optical fiber 16 for guiding emitted light is connected to this emission end.

The actuator 13 enters the input end of the optical waveguide 22 from the output end of the optical waveguide 21. This embodiment includes a cantilever (to be described later) for moving the shirt 14 so that light to be emitted (that is, light crossing the groove 23) is attenuated by a desired amount of attenuation, and is configured as a MEMS in the present embodiment. .

The actuator 13 includes a board 31 mounted on the support 11, two legs 3 2 a, 3 2 b, and two strip-shaped beams 3 3 a, 3 3 b, And a rectangular connection part 34. The beam portions 33a and 33b extend in parallel with the X-axis direction in plan view as viewed from the Z-axis direction. The connecting portion 34 is provided at the tip (free end, end in the + X direction) of the beam portions 33a, 33b, and is a portion that mechanically connects the beam portions 33a, 33b. It is.

A wiring pattern 35a (see FIGS. 7 to 9) made of, for example, an A1 film is formed on the substrate 31. The substrate 31 is an insulating substrate such as a glass substrate. However, if an insulating film is formed over the substrate 31, any material such as a silicon substrate can be used as the substrate 31.

The fixed end (the end in the X direction) of one beam 33 a is mechanically connected to the substrate 31 via the wiring pattern 35 a formed on the substrate 31 and the leg 32 a. It is connected. Similarly, the fixed end (the end in the X direction) of the other beam portion 33 b is connected to the wiring pattern 35 b (not shown) formed on the substrate 31 and the leg portion 32 b. It is mechanically connected to the substrate 31. The wiring pattern 35b is also made of the A1 film. The legs 32 a and 32 b are rising portions from the substrate 31.

In this way, the fixed ends of the beams 33a and 33b are mechanically connected to the substrate 31 via the wiring patterns 35a and 35b and the legs 32a and 32b, respectively. Connected. Further, as described above, the free ends of the beam portions 33a and 33b are mechanically connected by the connection portion 34.

Therefore, in the fourth embodiment, the beam portions 33a and 33b and the connection portion 34 force S constitute a cantilever (movable portion) having a cantilever structure as a whole. In the following description, the beam portions 33a and 33b and the connection portion 34 are collectively referred to as "power levers (33, 34)" as appropriate. In the present embodiment, the substrate 31 constitutes a fixed part.

A silicon oxide film is formed on the wiring patterns 35 a and 35 b on the substrate 31, on the region other than the vicinity of the legs 32 a and 32 b, and on other regions on the substrate 31. Protective film 36 is formed. Furthermore, the beam 33a of the cantilever (33, 34) is a thin film in which the lower SiN film 37 and the upper A1 film 38 are laminated, and acts as a leaf spring. It is composed of In other words, a panel force acts on the beam 33a in accordance with the position of the free end. The A1 film 38 in the beam portion 33a is used as a wiring to a current path for driving by Lorentz force described later.

As shown in FIG. 7, the beam portion 33a, when the driving signal (current for Lorentz force) described later is not supplied to the A1 film 38, the SiN film 37 and the A1 film 38 Due to this stress, it is curved upward (opposite side of substrate 31, + Z direction).

In FIG. 7, for convenience, the beam portion 33a is depicted as if it were bent at the root and extended diagonally upward, but actually, the beam portion 33a is entirely curved. Such a curved state can be realized by appropriately setting the film forming conditions of the SiN film 37 and the A1 film 38.

In the present embodiment, the leg 32 a on the fixed end side of the beam 33 a is such that the SiN film 37 and the A1 film 38 constituting the beam 33 a extend continuously as they are. It is composed of The A1 film 38 is electrically connected to the wiring pattern 35a at the leg 32a through an opening formed in the SiN film 37.

The other beam portion 33b and leg portion 32b have exactly the same structure as the above-described beam portion 33a and leg portion 32a, respectively.

The connecting portion 34 of the cantilever (33, 34) is composed of a SiN film 37 and an A1 film 38 extending continuously from the beam portions 33a, 33b. I have. Further, a shirt 14 is provided on the SIN film 37 of the connection portion 34. As shown in FIG. 6, the A1 film 38 has a portion on the connecting portion 34 extending in the Y-axis direction.

As can be seen from the above description, in the actuator 13, the wiring pattern 35 a below the leg 3 2 a, the beam 3 3 a → the connecting portion 3 4 → the A 1 film of the beam 3 3 b A current path is formed through 38 (electrical wiring) to the wiring pattern 35b (not shown) below the leg 32b.

Then, of this current path, the portion of the A1 film 38 extending in the Y-axis direction at the connection portion 34 becomes a current path for driving by Lorentz force. In the following description, the portion of the A1 film 38 extending in the Y-axis direction is abbreviated as “current path 38Y”. I do. The current path 38 Y forms a part of the cantilever (33, 34).

Actually, when the current path 38 Y is placed in the magnetic field in the X-axis direction, and a predetermined current (current for Lorentz force) is supplied to the current path 38 Y, the cantilever (33, 3 A Lorentz force (driving force) in the Z-axis direction is generated in the current path 38 Y so as to oppose the spring force of 4). The magnetic field in the X-axis direction is a magnetic field generated by the magnet 2.

Whether the direction of the Lorentz force is the + Z direction or the 1Z direction is determined by the direction of the Lorentz force current and the direction of the magnetic field. In the present embodiment, as described above, in a state where the current for Lorentz force is not supplied, as shown in FIG. 7, the beam portions 33a and 33b are curved upward, so that the Lorentz force is The direction of the application current may be determined so that the Lorentz force is generated only in the 1Z direction.

Although not shown in the drawing, the wiring patterns 35a and 35b on the substrate 31 can be connected to the external control unit 3 in the same manner as a normal silicon semiconductor element wiring method. . Then, the control unit 3 supplies a current for Lorentz force as a control signal to the current path 38Y.

The actuator 13 can be manufactured by using a semiconductor manufacturing technology such as formation and patterning of a film, etching, formation and removal of a sacrificial layer, and the like. For example, after forming a recess corresponding to the shirt 14 in the resist, the material (Au, Ni, and other metals) to be the shirt 14 is grown by electrolytic plating. Thereafter, the resist can be removed to form the resist. As the shirt 14, a material other than metal may be used.

In order to generate Lorentz force in the current path 38 Y of the connection part 34 of the cantilever (33, 34), the magnet 2 is attached to the lower surface of the support base 11 as shown in FIGS. 7 to 9. + Provided on the X side. In the fourth embodiment, as the magnet 2, a plate-shaped permanent magnet in which the + side in the X-axis direction is magnetized to the N pole and one side is magnetized to the S pole is used.

Therefore, in the vicinity of the current path 38 Y at the connection portion 34 of the cantilever (33, 34), a substantially uniform magnetic field is generated by the magnet 2 from the + side to one side along the X-axis direction. Will do. Note that, instead of the magnet 2, for example, a permanent magnet having another shape, an electromagnet, or the like may be used as the magnetic field generation unit.

Further, the variable optical attenuator of the fourth embodiment has a frame type as shown in FIGS. The spacer 17 is provided. Then, the optical waveguide substrate 12 is bonded to the substrate 31 of the actuator 13 via the spacer 17. The optical waveguide substrates 12 and 31 are aligned so that the shutter 14 of the actuator 13 can be inserted into the groove 23 of the optical waveguide substrate 12.

In addition, a space between the optical waveguide substrate 12 and the substrate 31 surrounded by the spacer 17 and a space of the groove 23 communicating therewith are filled with a refractive index matching liquid (not shown). Has been done. Note that the refractive index matching liquid does not necessarily have to be sealed. When a refractive index matching liquid is used, the loss of the light beam is smaller.

FIG. 7 shows a state where the current for Lorentz force is not supplied from the control unit 3 to the current path (35a → 38 → 35b). In this case, the Lorentz force does not act on the current path 38 Y of the connection portion 34 of the cantilever (33, 34), and the shutter 14 completely blocks the emission end of the optical waveguide 21. . For this reason, the attenuation is 100%. FIG. 8 shows a state where a moderate Lorentz force current is supplied from the control unit 3 to the current path (35a → 38 → 35b). In this case, a moderate Lorentz force acts downward on the current path 38Y of the connection portion 34 of the cantilever (33, 34). For this reason, the shirt 14 stops at a position where the Lorentz force and the spring force of the beam portions 33a and 33b are balanced, and blocks the lower half of the light emitting end of the optical waveguide 21. In this case, the attenuation is about 50%.

FIG. 9 shows a state where a large Lorentz force current is supplied from the control unit 3 to the current path (35a → 38 → 35b). In this case, a large Lorentz force acts downward on the current path 38 Y of the connection portion 34 of the cantilever (33, 34). For this reason, the shirt 14 stops at the position where the Lorentz force and the spring force of the beams 33 a and 33 b are balanced, and does not block the emission end of the optical waveguide 21 at all. In this case, the attenuation is almost 0%.

The operating state is not limited to the examples shown in FIGS. 7 to 9. By changing the value of the Lorentz force by changing the value of the current flowing from the control unit 3 to the current path (35a → 38 → 35b), The attenuation can be arbitrarily changed continuously from approximately 0% to 100%.

In the fourth embodiment, in response to an external attenuation command signal, the control unit 3 transmits a Lorentz force current having a magnitude corresponding to the attenuation indicated by the attenuation command signal to a current path. (35a → 38 → 35b). The circuit configuration itself does not require a special one, and can be easily realized by a combination of a DC current source or a DC voltage source and a resistor.

Further, the control unit 3 may perform open-loop control according to a table indicating the relationship between the current value and the attenuation measured in advance, or may include a detector that monitors the amount of light after attenuation. Based on the detection signal, feedback control may be performed so that the actual attenuation is equal to the attenuation indicated by the attenuation command signal.

Here, the variable optical attenuator 1 of the fourth embodiment is modeled as shown in FIG. 10, and the following calculation is performed according to this model. In other words, the current (wire current) flowing through the straight wire 38 '(modeling the current path Y of the connection 34) (wire current) is 10mA, 20mA, 3 OmA, 4 OmA, 50mA, and the wire 38' and the board 3 Calculate the Lorentz force acting on the wire 38 'when the distance d2 between 1 and 2 is changed. Further, the panel forces of the beam portions 33a and 33b with respect to the interval d2 are also calculated.

In the model shown in Fig. 10, only the spring force and Lorentz force are applied to the wire 38 'in the opposite directions. Beams 33a and 33b are considered to be ideal panels. In the calculation, the length of the wire 38 'was set to 50 / im. The wire 38 'is assumed to be in a uniform magnetic field with a magnetic flux density of 0.1 (T). Furthermore, the initial value of the interval d 2 (the interval when the wire current is 0, that is, the interval at which the panel force becomes 0) is 10 μm, and the spring constant of the beams 33 a and 33 b is 3 X 10— 2 ( N / m).

Figure 11 shows the result of the calculation. The horizontal axis in FIG. 11 represents the interval d2. The vertical axis represents Lorentz force and panel force (N). In FIG. 11, the solid line indicates the Lorentz force, and the broken line indicates the spring force. Explaining the numerical notation on the vertical axis in FIG. 11, for example, “3.0E—07” means “3.0 X 10—07”. Point S in FIG. 11 corresponds to the beginning of the interval d2.

Next, based on this calculation result (Fig. 11), we will examine how the Lorentz force and the spring force balance (that is, the stopping position of the electric wire 38 ').

The Lorentz force is constant independently of the distance d2 between the electric wire 38 'and the substrate 31. For this reason, the broken line representing the spring force and the solid line representing the Lorentz force intersect at equally spaced points A to E. For example, if the current value of wire 38 'is 1 OmA, it crosses at point A. In this case, the electric wire 38 'starts from the start point S (the initial value of the interval d2). At point A, the panel force and Lorentz force are balanced, and on the left side, the spring force is stronger than the Lorentz force. It stops at point A and its position is kept stable.

Also, if the current value of the wire 38 'is increased (20mA → 3Απι〜 → ~), the stop position of the wire 38' (point C → point C…) approaches the board 31 (d 2 → 0 ). As shown in Fig. 11, the stopping positions (intersections A to E of the Lorentz force and the panel force) of the wire 38 'at each current value are arranged at equal intervals, and a straight line is drawn between the current value and the interval d2. It is clear that there is a property.

Next, in order to compare with the calculation results in Fig. 11, a conventional variable optical attenuator (see Figs. 15 and 16) was modeled as shown in Fig. 12, and similar calculation was performed according to this model. I do. The reference numerals in the variable optical attenuator of the comparative example (Fig. 12) correspond to those used in Figs. “1 15” is a bottom plate as a fixed electrode, “1 16” is a top plate as a movable electrode, and “1 17” is a flexure portion.

The calculation of the comparative example will be described. The voltage (electrode voltage) between the plates 1 15 and 1 16 is 5 V, 10 V, 15 V, 20 V and 25 V, and the distance between the plates 1 15 and 116 (electrode distance dl) is Calculate the electrostatic force between the plates 115 and 116 when changing. Further, the panel force of the flexure portion 117 with respect to the electrode interval d1 is also calculated.

In the model shown in FIG. 12, only the spring force and the electrostatic force are applied to the top plate 116 in the opposite directions. The flexure section 117 was described as an ideal panel. Both plates 115 and 1 16 were parallel plates, and the relative permittivity between them was 1. Furthermore, in the calculation, both plates 1 15 and 1 16 are square plates of 50 μπι angle, and the initial value of the electrode interval d 1 (interval when the voltage between the electrodes is 0 and the panel force becomes 0) Was set to 10 m, and the panel constant of the flexure section 1 17 was set to 3 × 10-2 (N / m).

Figure 13 shows the result of the calculation. The horizontal axis in FIG. 13 represents the interval dl. The vertical axis represents electrostatic force and panel force (N). In Fig. 13, the solid line indicates the electrostatic force. The dashed line indicates the panel force. Explaining the notation of numerical values on the vertical axis in FIG. 13, for example, “3.0 E—07” means “3.0 X 10—07”. Point S in Fig. 13 corresponds to the initial value of interval d1.

Next, based on the calculation results (Fig. 13), we will examine how the electrostatic force and the panel force balance (ie, the stop position of the top plate 116). If the solid line is above the dashed line, the electrostatic force is stronger than the panel force, and both plates 1 15 and 1 16 will attract each other and the electrode gap d 1 will be narrower.

For example, when the voltage between the electrodes is 25 V, the solid line is always above the dashed line, so the top plate 116 starts from the point S at the start position (the initial value of the interval dl) Ι Ο μm It starts and the force S keeps the electrode gap d1 narrow. Since the electrostatic force always exceeds the panel force, it does not stop until both plates 115 and 116 come into contact.

On the other hand, when the voltage between the electrodes is 15 V, the solid line and the broken line intersect at point C where the electrode spacing d1 is 9 / xm, and below that, the panel force exceeds the electrostatic force. Start at point S at 10 / in intervals and stop at point C at 9 / m intervals. In the calculation example in Fig. 13, the voltage between the electrodes at the point where the solid and broken lines intersect is 20 V, and the intersection (point D) is near the 7 µπ interval.

For this reason, it is impossible to balance the electrostatic force and the spring force when the electrode interval d1 is 7/1 m or less. That is, the operating range as the electrode spacing d1 is only 10 / χιη to 7 μιη, which is very narrow. In addition, looking at the balance points A, ,, C, and D when the inter-electrode voltage is 5 V, 10 V, 15 V, and 20 V, there is no linearity between the inter-electrode voltage value and the electrode interval. I understand.

In addition, if the device is operated at a voltage between the electrodes of about 20 V and stops at around 7 μm, the area around 7 μm is a very unstable area, and the balance may be lost due to electrical noise or mechanical vibration. May collapse once. Then, when it enters the area to the left of point D in Fig. 13, the electrostatic force is always greater than the panel force, and both plates 115, 116 come into contact (electric short-circuit).

Now, the model calculation of the fourth embodiment (FIG. 11) is compared with the model calculation of the comparative example (FIG. 13).

In the case of Fig. 11, by changing the current value of the wire 38 ', the wire 38' It can be controlled freely with a box. Therefore, according to the fourth embodiment, the range in which the shirt 14 can be moved is widened, thereby increasing the degree of freedom in design. In the fourth embodiment, a Lorentz force is used instead of an electrostatic force, so that a high voltage is not required. Furthermore, in the case of FIG. 11, there is linearity between the current value of the wire 38 'and the distance d2 (that is, the position of the shirt 14). Therefore, according to the fourth embodiment, it is easy to control the amount of attenuation. That is, the desired amount of attenuation can be stably obtained depending on the position of the shirt 14 and the controllability is excellent.

Further, from the relationship between the Lorentz force and the panel force shown in Fig. 11, even if the electric wire 38 'is located at any of the balance points (A to E), as long as the current value is not changed, the balance point is not changed. Is stably maintained. For this reason, even if the position of the wire 38 'is temporarily shifted due to electrical noise or mechanical vibration, the wire 38' will automatically return to the balance point and the balance may be lost. Absent. Therefore, according to the fourth embodiment, a desired amount of attenuation can be stably obtained.

Of course, an electrical short as in the comparative example of FIG. 13 cannot occur. That is, since the position of the electric wires 38, can be accurately controlled, it is extremely easy to control the electric wires 38, so that they do not contact the substrate 31, and the electric wires 38 'must be in contact with the substrate 31. No electrical shorts can occur.

Actually, the electric wire 38 ′ (that is, the current path 38Y) is disposed above the SiN film 37, which is an insulating film, and the surface of the substrate 31 is formed of a protective film such as a silicon oxide film. Since it is insulated by 36, even if the connecting portion 34 including the current path 38Y contacts the substrate 31 as shown in FIG. 9, for example, an electrical short circuit cannot occur.

In the above-described fourth embodiment, the Lorentz force is controlled by controlling the current for the oral Lenz force supplied from the control unit 3 to the current path 38Y, but the present invention is not limited to this. For example, when an electromagnet is used as the magnet 2, the control unit 3 may control only the magnetic field generated by the magnet 2. Alternatively, both the current applied to the current path 38 Y and the magnetic field generated by the magnet 2 may be controlled. Further, in the above-described fourth embodiment, the configuration example in which the state shown in FIG. 7 (curved upward) is described when the current for the Lorentz force is not supplied to the current path 38 Y has been described. It is not limited to. For example, if the current for Lorentz force is not supplied In the case where the current does not curve upward or downward as shown in FIG. 8, it is preferable that the direction of the Lorentz force current can be changed to any direction. Also, when the current for Lorentz force is not supplied and it curves downward as shown in Fig. 9, the direction of the current for Lorentz force is determined so that the Lorentz force is generated only in the + Z direction. Preferably.

Further, in the above-described fourth embodiment, the actuator 13 has a cantilever structure manufactured by a surface MEMS process for manufacturing a thin film structure on a substrate, but the present invention is not limited to this. . For example, instead of the actuator 13, other actuators manufactured by a substrate MEMS process for etching a substrate to manufacture a structure, an actuator having a doubly supported structure, or a conventional variable optical attenuation An actuator having a "lever structure" similar to that of the vessel may be used.

(Fifth embodiment)

Finally, a variable optical attenuator (FIG. 14) according to a fifth embodiment of the present invention will be described. FIG. 14 shows only a part of the variable optical attenuator of the fifth embodiment. The constituent elements not shown are the same optical waveguide substrate and spacer as in FIGS. 6 to 9. The variable optical attenuator according to the fifth embodiment has the same basic configuration as that shown in FIGS.

In the variable optical attenuator of the fifth embodiment, the second SIN film 39 is formed so as to cover the upper surface of the A1 film 38 of the force fulever (33, 34) constituting the actuator 13 described above. Is provided. The linear expansion coefficient of the SiN film 39 is equal to that of the cantilever (33, 34).

As described above, in the variable optical attenuator of the fifth embodiment, both surfaces of the A1 film 38 of the cantilever (33, 34) are sandwiched by the SIN films having the same linear expansion coefficient and the same film thickness. The following effects are obtained. In other words, when controlling the position of the cantilever (3 3, 3 4), even if the current supplied to the A 1 film 38 slightly generates heat, the both sides of the A 1 film 38 are equal. To stretch. Therefore, the upward warpage moment and the downward warpage moment become equal, and no distortion such as warpage or deformation occurs. Also, even if the ambient temperature fluctuates, no distortion such as warpage or deformation occurs.

Here, the film thicknesses were made equal. However, the present invention is not limited to this. Even if the film thicknesses are not equal, the stress is reduced compared to the conventional configuration, This has the effect of reducing distortion such as warpage and deformation.

The variable optical attenuator according to the fifth embodiment is configured such that the cantilever (33, 34) is not distorted in addition to employing the drive by the Lorentz force described above. Therefore, the controllability is further improved.

In the fifth embodiment, in order to prevent the cantilever (33, 34) from being distorted, both surfaces of the A1 film 38 are sandwiched between SiN films having the same linear expansion coefficient and the same film thickness. However, the present invention is not limited to this. For example, a dummy A1 film may be provided on the lower surface of the 3iN film 37 of the cantilever (33, 34), and both surfaces of the SiN film 37 may be sandwiched between A1 films having the same linear expansion coefficient. Good.

In the above-described fourth and fifth embodiments, the shirt 14 is supported on the upper surface of the cantilever (33, 34). However, the present invention can be applied to a cantilever that supports the shirt 14 on the lower surface. .

Further, in the above-described embodiment, the cantilever is formed of a silicon nitride thin film (that is, a SiN film), but a thin film such as an oxide film may be used instead. Industrial potential

According to the present invention, it is possible to provide a cantilever, a light beam adjusting device, a variable optical attenuator, and a variable optical attenuator excellent in controllability.

Claims

The scope of the claims

(1) In a cantilever for moving an optical member insertable into a groove provided so as to traverse a part or all of an optical path in a direction perpendicular to the optical path,

The cantilever supports the optical member by an insulating thin film, and moves the optical member by a voltage or a current applied to an electric wiring disposed on the insulating thin film. The insulating thin film is configured so as not to cause a stretching difference on both surfaces.

A cantilever characterized by the following:

(2) In the cantilever according to claim 1,

Dummy electric wiring is disposed on the surface of the insulating thin film opposite to the surface on which the electric wiring is disposed so as to be plane-symmetric with respect to the electric wiring.

(3) In the cantilever according to claim 1,

Of the two surfaces of the insulating thin film, a surface opposite to the surface on which the electric wiring is provided! Dummy electric wiring is disposed so as to be point-symmetric with respect to the electric wiring.

(4) In the cantilever according to claim 1,

Of the two surfaces of the insulating thin film, an insulating material having the same coefficient of linear expansion as the electric wiring was laminated on a surface opposite to the surface on which the electric wiring was provided.

Features <

(5) an optical waveguide disposed on the substrate;

A groove provided to traverse part or all of the optical path of the optical waveguide; and an optical member insertable into the groove,

The optical member is supported by an insulating thin film, and the optical member is perpendicular to the optical path. With a cantilever to move in the direction,

The force cantilever moves the optical member by a voltage or a current applied to electric wiring provided on the insulating thin film, and has a coefficient of linear expansion equal to that of the electric wiring. A light beam adjusting device, which is configured not to cause a difference in extension between both surfaces of the insulating thin film.

(6) Light placed on the substrate:

A slit provided so as to traverse part or all of the optical path of the optical fiber;

An optical member insertable into the slit,

A cantilever for supporting the optical member by an insulating thin film and moving the optical member in a direction perpendicular to the optical path;

The cantilever moves the optical member by a voltage or a current applied to electric wiring provided on the insulating thin film, and uses a material having a linear expansion coefficient equal to that of the electric wiring to form the insulating thin film. It is constructed so that there is no difference in extension on both sides of

A light beam adjusting device characterized by the above-mentioned.

(7) In the light beam adjusting device according to claim 5 or 6,

In the cantilever, a dummy electric wiring is arranged on a surface of the insulating thin film opposite to a surface on which the electric wiring is arranged so as to be plane-symmetric with respect to the electric wiring. Was

A light beam adjusting device, characterized in that:

(8) In the light beam adjusting device according to claim 5 or 6,

In the cantilever, a dummy electric wiring is disposed on the surface of the insulating thin film opposite to the surface on which the electric wiring is disposed so as to be point-symmetric with respect to the electric wiring. Was

A light beam adjusting device characterized by the above-mentioned.

(9) In the light beam adjusting device according to claim 5 or 6,

The force-chinch lever is characterized in that, of the two surfaces of the insulating thin film, an insulating material having the same linear expansion coefficient as that of the electric wiring is laminated on a surface opposite to a surface on which the electric wiring is provided. Light beam adjustment device.

(10) an optical waveguide disposed on a substrate,

A groove provided to traverse the optical path of the optical waveguide,

An optical member insertable into the groove,

A cantilever that supports the optical member with an insulating thin film, moves the optical member in a direction perpendicular to the optical path, and moves the optical member so that the amount of attenuation of light traversing the groove becomes a desired value. ,

The cantilever moves the optical member by a voltage or a current applied to an electric wiring provided on the insulating thin film,

The electric wiring has a surface opposite to the insulating thin film covered with a material having the same linear expansion coefficient as the insulating thin film.

A variable optical attenuator characterized in that:

(11) In the variable optical attenuator according to claim 10,

In the electric wiring, the opposite surface is covered with a material having the same linear expansion coefficient and the same thickness as the insulating thin film.

A variable optical attenuator characterized in that:

(1 2) an optical waveguide arranged on a substrate,

A groove provided to traverse the optical path of the optical waveguide,

An optical member insertable into the groove,

A cantilever that supports the optical member, moves the optical member in a direction perpendicular to the optical path, and moves the optical member to a position where the amount of attenuation of light traversing the groove becomes a desired value. A free end that is movable with respect to the And supporting the optical member, moving the free end by a voltage or a current applied to electric wiring provided on the cantilever, and providing a spring force according to the position of the free end.

The electric wiring has a current path arranged in a magnetic field to generate a Lorentz force against the panel force by the voltage or the current.

A variable optical attenuator characterized in that:

(13) In the variable optical attenuator according to claim 12,

The cantilever supports the optical member by a thin film

A variable optical attenuator characterized in that:

(14) In the variable optical attenuator according to claim 13,

The cantilever supports the optical member with an insulating thin film, the electric wiring is provided on the insulating thin film, and a material having a coefficient of linear expansion equal to that of the electric wiring is used to generate a difference in extension between both surfaces of the insulating thin film. Not configured

A variable optical attenuator characterized in that:

(15) The variable optical attenuator according to claim 13,

The cantilever supports the optical member with an insulating thin film, the electrical wiring is disposed on the insulating thin film,

A variable optical attenuator characterized in that:

(16) In the variable optical attenuator according to claim 15,

A variable optical attenuator characterized in that:

(17) The variable optical attenuator according to any one of (12) to (16), and a magnetic field generator configured to generate the magnetic field.

A variable optical attenuator characterized by the above-mentioned.

(18) In the variable optical attenuator according to claim 17,

A control unit that controls at least one of the current in the current path and the magnetic field.

A variable optical attenuator characterized by the above-mentioned.