JP3672897B2 - Optical attenuator and optical attenuator array - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to an optical attenuator and an optical attenuator array that are used in branch nodes of an optical network system and adjust the level of an optical signal.
[0002]
[Prior art]
In optical communication systems, various and flexible optical transmission systems are required with the progress of optical wavelength division multiplexing and transmission technology. In an optical transmission system, it is required to adjust the level of an optical signal wavelength-multiplexed at an arbitrary node or to align the optical level of wavelength-multiplexed light. An optical attenuator with a variable attenuation factor is used for such applications. As a conventional optical attenuator, as shown in US Pat. No. 6,137,941, for example, a light guide for light projection and a light guide for light reception are held toward the lens, and the angle of the mirror provided at the focal position is changed. Thus, there is known one in which the attenuation rate is changed by changing the optical axis of the projected light applied to the light receiving guide.
[0003]
As another conventional optical attenuator, an optical attenuator using a distributed ND filter is known. The distributed ND filter is formed by depositing a metal film having a large light absorption rate such as chromium or inconel on a transparent glass substrate with a distribution in the longitudinal direction. In this optical attenuator, the ND filter is arranged substantially perpendicular to the optical axis, the ND filter is moved in the distribution direction, and the light transmittance is changed by changing the thickness of the metal film through which the light passes to change the attenuation factor. I am doing so.
[0004]
[Problems to be solved by the invention]
Along with recent advances in wavelength division multiplexing technology, information transmitted through optical fibers is distributed (cross-connected) as signals of each wavelength, selected, or new signals are added and dropped to the required path. It is transmitted. In such a node, optical parts such as a multiplexer / demultiplexer, an optical switch, and an optical attenuator are used. These parts are required to have extremely low loss. In addition to this, there is a need for an inexpensive optical component that is small in size and can easily be multi-channeled.
[0005]
However, according to the conventional method of adjusting the attenuation rate by adjusting the coupling rate by shifting the optical axis, it is difficult to manufacture a small optical attenuator. Further, there is a drawback that it is difficult to construct an optical attenuator array in which a large number of optical attenuators are arranged. In the case of an optical attenuator that changes the attenuation rate by sliding an ND filter with a metal film distributed in its distribution direction, the size of the element is limited by the size of the ND filter and the motor that drives the ND filter. There was a drawback that it was difficult. In addition, since the movement is performed using a motor, there is a drawback that the variable speed is limited.
[0006]
The present invention has been made in view of such conventional problems, and an object of the present invention is to provide an optical attenuator and an optical attenuator array that are small in size and excellent in mass productivity.
[0007]
[Means for Solving the Problems]
An optical attenuator according to claim 1 of the present application includes an optical fiber disposed in the V-shaped groove of a block having a V-shaped groove parallel to the base, and an incident portion that emits light in parallel with the base; An optical fiber having an optical fiber disposed in the V-shaped groove of a block disposed opposite to the incident portion and having a V-shaped groove parallel to the base and receiving light from the incident portion side an emission portion having a said arranged laterally between the entrance portion and the exit portion, and a mirror unit including a pivotable tilting mirrors, the tilt angle of the tilt mirrors of said mirror unit to continuously change A tilt mirror control unit, a first reflection surface that is disposed between the incident unit and the emission unit, reflects light from the incident unit to the tilt mirror, and reflects light reflected by the tilt mirror. Reflected toward the exit 'S a reflection unit having a reflection surface, provided with the mirror unit, a part of the movable portion in which the reflective surface is formed on the upper surface is connected to the mirror substrate by a hinge portion, tilting mirror which rotates about its hinges And an electrode formed on the mirror substrate, and the tilt mirror control unit is a variable voltage source that applies a voltage between the tilt mirror and the electrode on the mirror substrate. The tilt mirror is rotated by changing the voltage .
[0008]
An optical attenuator according to claim 2 of the present application includes an optical fiber disposed in the V-shaped groove of a block having a V-shaped groove parallel to the base, and an incident portion that emits light in parallel with the base; An optical fiber having an optical fiber disposed in the V-shaped groove of a block disposed opposite to the incident portion and having a V-shaped groove parallel to the base and receiving light from the incident portion side And a mirror unit including a shift mirror disposed on a side between the incident portion and the emission portion and changing a distance between the incidence portion and the emission portion, and a shift mirror of the mirror unit. A shift mirror control unit that changes the position, a first reflection surface that is disposed between the incident unit and the emission unit and reflects light from the incident unit to the shift mirror, and is reflected by the shift mirror. The emitted light A reflecting unit having a second reflecting surface that reflects toward the surface, and the mirror unit includes a movable mirror having a reflecting surface formed on an upper surface thereof, and an outer peripheral portion of the movable unit held on the mirror substrate so as to be movable up and down. And an electrode formed on the mirror substrate, and the shift mirror control unit is a variable voltage source that applies a voltage between the shift mirror and the electrode on the mirror substrate. The shift mirror is rotated by changing the voltage.
[0009]
An optical attenuator according to claim 3 of the present application includes an optical fiber disposed in the V-shaped groove of a block having a V-shaped groove parallel to the base, and an incident portion that emits light in parallel with the base; An optical fiber having an optical fiber disposed in the V-shaped groove of a block disposed opposite to the incident portion and having a V-shaped groove parallel to the base and receiving light from the incident portion side And a mirror unit including a shift mirror disposed on a side between the incident portion and the emission portion and changing a distance between the incidence portion and the emission portion, and a shift mirror of the mirror unit. A shift mirror control unit that changes the position, a first reflection surface that is disposed between the incident unit and the emission unit and reflects light from the incident unit to the shift mirror, and is reflected by the shift mirror. The emitted light A reflection unit having a second reflection surface that reflects toward the substrate, wherein the mirror unit is disposed on an upper portion of the substrate and has a reflection surface on the upper surface, and between the shift mirror and the substrate. A piezoelectric actuator that holds and moves the shift mirror up and down, and the shift mirror control unit applies a voltage to the piezoelectric actuator to move the shift mirror up and down parallel to the surface. It is a feature.
[0012]
According to a fourth aspect of the present invention, in the optical attenuator according to any one of the first to third aspects, the incident portion and the emission portion are provided with an optical fiber and collimated light emitted from the optical fiber provided at the tip thereof. It is a lens part to perform.
[0013]
According to a fifth aspect of the present invention, in the optical attenuator according to the fourth aspect , the lens portion is a ball lens and is attached to the tip of each optical fiber.
[0015]
A sixth aspect of the present invention is the optical attenuator according to any one of the first to third aspects, wherein the reflective unit has the first and second reflective surfaces having a V-shaped cross section on a lower surface thereof. The first reflection surface is formed toward the incident portion, and the second reflection surface is formed toward the emission portion.
[0016]
The invention of claim 7 of the present application is the optical attenuator according to any one of claims 1 to 3 , wherein the reflection unit has the first and second reflection surfaces having a V-shaped cross section on the upper surface thereof. The first reflection surface is formed toward the incident portion, and the second reflection surface is formed toward the emission portion.
[0017]
The invention of claim 8 of the present application is an optical attenuator array in which a plurality of the optical attenuators of any one of claims 1 to 7 are arranged in parallel on the base.
[0018]
DETAILED DESCRIPTION OF THE INVENTION
FIG. 1 is a perspective view showing a four-channel optical attenuator array in which four optical attenuator units according to Embodiment 1 of the present invention are arranged in parallel, and FIG. 2 is a sectional view thereof. As shown in these drawings, the optical attenuator array according to the present embodiment has a printed circuit board 2 and a mirror substrate 3 fixed on top of a base 1, and spacers 4 and 5 are provided on the left and right sides of the upper surface. In order to facilitate the following description, it is assumed that the base 1, the printed circuit board 2, and the mirror substrate 3 are arranged on a plane parallel to the XY plane. A block 6a having a plurality of V-shaped grooves is disposed on the spacer 4 as shown in a sectional view in FIG. A block 6b having a V-shaped groove is disposed on the spacer 5 at a position corresponding to the block 6a, as shown in a sectional view in FIG. In the block 6a, V-shaped grooves 7a, 7b, 7c, 7d... Facing in the X-axis direction are formed in parallel along the Y-axis. Similarly, V-shaped grooves 8a, 8b, 8c, 8d... Facing in the X-axis direction are also provided in the block 6b.
[0019]
The optical fibers 11a, 11b,... Having the same height as the V-shaped grooves 7a, 7b,... Of the block 6a are arranged in parallel as incident optical fibers. , 12b... Are integrally formed. In addition, in the V-shaped grooves 8a, 8b,... Of the block 6b, which are symmetrical to this, optical fibers 13a, 13b,... Having exactly the same height are arranged in parallel as outgoing optical fibers. The collimating lenses 14a, 14b,... Are integrally formed at the tip portion. The optical fibers 11a, 11b,... And the collimating lenses 12a, 12b,... At the tips thereof constitute an incident part, and the optical fibers 13a, 13b,. Constitutes an emitting part.
[0020]
Here, the optical fibers 11 a and 13 a and the collimating lenses 12 a and 14 a constitute an incident / exit section of a first channel optical attenuator formed in a plane parallel to the XZ plane perpendicular to the base 1. The optical fibers 11b and 13b and the collimating lenses 12b and 14b constitute an incident / exit portion of the second channel optical attenuator, and so on. Thus, by inserting and fixing the input / output portions in the V-shaped grooves of the blocks 6a and 6b, the optical axis can be accurately positioned without fine adjustment.
[0021]
A reflection unit 20 is provided above the blocks 6a and 6d so as to straddle these blocks via spacers 9a and 9b. As shown in FIGS. 1 and 2, the reflecting unit 20 is a rectangular parallelepiped member, and a V-shaped reflecting surface is provided on the lower surface. As shown in FIG. 5, the reflection unit 20 includes a first reflection surface M1 on which light from the optical fiber 11 and the collimating lens 12 is incident, and a second reflection surface M2 that is symmetrical to the first reflection surface M1. Here, the first reflecting surface M1 is an incident-side reflecting surface that reflects light from the incident portion, and the second reflecting surface M2 is an emitting-side reflecting surface that reflects light from a tilt mirror described later. An angle between a horizontal line parallel to the base and the reflecting surfaces M1 and M2 is defined as θ.
[0022]
On the upper surface of the mirror substrate 3, mirror units 21a, 21b,... Are located at positions that intersect a plane perpendicular to the base including the optical axes L1a and L2a, and positions that intersect a plane perpendicular to the base including the optical axes L1b and L2b.・ ・ Is placed. Hereinafter, the peripheral portion of the mirror unit 21 according to the first example will be described with reference to FIG. The mirror unit 21 has first and second electrodes 22a and 22b formed symmetrically on the upper surface of the mirror substrate 3 as shown in the figure. Further, third and fourth electrodes 24a and 24b serving as tilt mirror holding portions are arranged on the sides thereof via spacers 23a and 23b. A tilt mirror 26 is rotatably held from these electrodes through a hinge 25. A line passing through the centers of the hinge 25 and the tilt mirror 26 serves as a rotation axis, and the first and second electrodes 22a and 22b of the mirror substrate 3 are divided along the rotation axis. . The rotation axis is an axis parallel to the Y axis. The tilt mirror 26 is, for example, a circular or hexagonal member having a diameter of about 90 μm, and the surface thereof is a mirror and also serves as an electrode. As shown in FIG. 7, a voltage can be applied via a variable voltage source 27 between the electrodes 24a and 24b electrically connected to the tilt mirror 26 and one of the electrodes 22a and 22b. The The electrodes 24a and 24b are for supplying a voltage while holding the tilt mirror 26, and only one of them may be an electrode.
[0023]
FIG. 7A shows a state where no voltage is applied, and FIG. 7B shows a state where a certain voltage is applied. By applying a voltage as shown in FIG. 7B, an electrostatic force acts between the tilt mirror 26 and the one electrode 22a, and the tilt mirror 26 can be rotated along the hinge 25. By changing this voltage, the tilt angle φ can be set with an external voltage. Here, the variable voltage source 27 constitutes a tilt mirror control unit that continuously changes the tilt angle φ of the tilt mirror.
[0024]
Further, as a rotatable mirror unit, for example, SERIES 8001 manufactured by MEMS Optical may be used.
[0025]
Next, the operation principle of the present embodiment will be described with reference to FIGS. Hereinafter, the first channel will be described, but the same applies to other channels. First, it is assumed that the rotatable tilt mirror 26a below the reflective substrate 20 is in a state parallel to the base 1 as shown in FIG. At this time, the light from the optical fiber 11a enters the first reflection surface M1 of the reflection unit 20 through the optical axis L1a from the collimator lens 12a. The angle between the reflecting surface M1 and the optical axis L1a parallel to the base is θ, and is reflected by the reflecting surface M1 and applied to the tilt mirror 26a. Here, the incident angle with respect to the tilt mirror 26a is 90 ° -2θ, and this light is reflected by the tilt mirror 26a. The optical axis of the reflected light is inclined 2θ with respect to the horizontal plane, and is reflected by the reflecting surface M2 of the reflecting unit 20. Since the angle of the reflection surface M2 with respect to the horizontal plane is also θ as with the reflection surface M1, the incident angle to the reflection surface M2 is 90 ° −θ. Accordingly, the light reflected by the reflecting surface M2 becomes horizontal as shown in the figure, and is added to the collimating lens 14a and the optical fiber 13a which are the emitting portions.
[0026]
Now, as shown in FIG. 8, the second state in which the tilt mirror 26a is tilted by the tilt angle φ will be described. In this case, the light from the optical fiber 11a is reflected by the reflecting surface M1 and then applied to the tilt mirror 26a. At this time, the angle between the Z axis perpendicular to the base 1 and the reflected light is 90 ° -2θ, and the incident angle to the tilt mirror 26a is 90 ° -2θ + φ. This light is reflected again by the tilt mirror 26a. Therefore, the angle between the Z axis and the reflected light is 90 ° −2θ + 2φ. This reflected light is incident on the second reflecting surface M2. Accordingly, the light is reflected again by the reflecting surface M2, but is slightly shifted upward from the original optical axis L2a, so that the amount of light incident on the optical fiber 13a decreases. Therefore, the attenuation rate can be varied by continuously changing the tilt angle φ of the tilt mirror 26a.
[0027]
Here, for example, the inclination angle θ of the horizontal surfaces of the reflecting surfaces M1 and M2 is 22.5 °, the distance X1 between the collimating lens 12a and the reflecting point of the reflecting unit 20 is 0.7 mm, and the optical axis L2a of the second reflecting surface M2 The interval X2 from the reflection point to the collimating lens 14a is 0.7 mm, and the interval H between the optical axes L1a and L2a and the incident point of the tilt mirror is 1 mm. FIG. 9 is a graph showing the change of the attenuation rate with respect to the tilt angle φ in this case.
[0028]
In this case, the interval (working distance) from the incidence of light to the emergence is about 4.2 mm. Therefore, the working distance, which is the traveling distance in the light space, can be made extremely small. For this reason, a lens fiber, a ball lens fiber, etc. can be employ | adopted and an attenuation factor can be made small. For this reason, a small mirror with a small diameter can be used as a tilt mirror. If the tilt mirror is small, the tilt mirror can be rotated at high speed with low voltage drive, so that the adjustment rate of the attenuation rate can be increased.
[0029]
The above description is for an optical attenuator for one channel between the two optical fibers 11a and 13a. As shown in FIGS. 1 and 2, in an array type optical attenuator in which a large number of pairs of optical fibers are arranged in the lateral direction, four channels of light can be obtained by using the tilt mirrors 26a, 26b, 26c, and 26d. An attenuator array can be realized. Further, not limited to four channels, if an arbitrary natural number is n, an n-channel optical attenuator array can be realized by arranging n × 2 optical fibers in parallel.
[0030]
The reflection unit 20 described above is disposed on the optical axis of the pair of optical fibers, and the lower surfaces thereof are the reflection surfaces M1 and M2. However, as shown in FIG. , L2 may be arranged. In this case, the reflection unit 40 is a glass block, and the upper surfaces thereof are the first and second reflection surfaces M1 and M2. The surface facing the optical fiber 11a of the reflection unit 40 is given a non-reflective coating as a vertical surface, and the surface facing the optical fiber 13a is similarly given a non-reflective coating as a vertical surface. Further, a non-reflective coating is also applied to the lower surface of the reflection unit 40. In this case as well, a similar function can be achieved by arranging a tilt mirror below the reflection unit 40. In this case, the incidence from the optical fiber 11a to the reflection unit 40 and the emission from the reflection unit 40 to the optical fiber 13a are perpendicular entrance and exit, but the incidence to the tilt mirror and the reflection from the tilt mirror are Refracts because the axis is not perpendicular. Therefore, the angle θ of the reflecting surfaces M1 and M2 of the reflecting unit needs to be an angle in consideration of the refractive index.
[0031]
Next, a second embodiment of the present invention will be described. In this embodiment, a shift mirror 51 is used in place of the tilt mirror as shown in FIG. 11, and the other configuration is the same as that of the first embodiment described above, and detailed description thereof is omitted. In this embodiment, the mirror units 51a, 51b,... Are arranged at the positions where the mirror units 21a, 21b,. The mirror units 51a, 51b,... Move the shift mirror up and down in parallel with the XY plane, and the shift amount can be controlled by an external voltage. As shown in FIG. 11, if the mirror of the mirror unit 51a can be moved up and down, the position of the reflected light is shifted in parallel to the reference position, and the optical axis of the light incident on the collimating lens 14a changes.
[0032]
Since the mirror units 51a, 51b,... Have the same structure, an example of the mirror unit 51a using a microelectromechanical system (MEMS) will be described with reference to FIGS. In the mirror unit 51a, an electrode 52 is formed at the center position of the upper surface of the mirror substrate 3. On the sides, hinges 55 are held by spacers 53a and 53c at the four corners. The above-described electrode 52 is formed below the mirror 56 formed at the center position. The shift mirror is a circular or polygonal member whose diameter is slightly larger than the beam size of incident light, and its surface is a mirror and also serves as an electrode. As shown in FIG. 13, a voltage can be applied via a variable voltage source 57 between the shift mirror 56 and the electrode 52 on the substrate. By applying a voltage here, the shift mirror 56 at the center moves up and down in parallel with the substrate in accordance with the voltage. If the shift amount of the vertical movement is Δ, the incident amount to the optical fiber 13a changes according to the shift amount Δ in the case of the same size as shown in FIG. If the shift amount Δ is changed according to the voltage, the amount of optical axis deviation also changes, and the attenuation amount can be continuously changed. FIG. 14 shows the change in attenuation with respect to the shift amount Δ in the case of a mirror unit having the same dimensions as in FIG. In this way, by changing the shift amount Δ by the voltage, the attenuation amount can be continuously changed.
[0033]
Instead of the MEMS mirror, a piezoelectric actuator may be provided on the mirror substrate, and a shift mirror may be provided on the piezoelectric actuator. Also in this case, the mirror surface can be moved up and down parallel to the XY plane by changing the voltage applied to the piezoelectric actuator. Therefore, the attenuation can be changed by changing the shift amount according to the applied voltage.
[0034]
Further, in the above-described embodiment, as shown in FIG. 15A, a case where a lens fiber is attached as a collimating lens to the tip of each optical fiber is described. Instead, as shown in FIG. 15B, an optical fiber having small ball lens collimators 61a and 62a attached to the tip of the optical fiber may be used. In this case, the working distance can be made longer than that of the lens fiber. Further, a collimator in which each optical fiber is connected using a normal aspherical lens, a GRIN lens, or a microlens array as a collimating lens may be employed.
[0035]
【The invention's effect】
As described in detail above, according to the first to eighth aspects of the present invention, input / output light can be coupled at a short distance, and a small and inexpensive optical attenuator can be realized. Further, it is possible to make an optical attenuator easy to align the optical axis and highly reliable. Furthermore, the incident / exit part can be easily positioned by holding the incident / exit part in a block having a V-shaped groove. Further, by forming the optical attenuator in an array shape, an n-channel optical attenuator array can be easily realized.
[Brief description of the drawings]
FIG. 1 is a perspective view showing an overall configuration of an optical attenuator according to Embodiment 1 of the present invention.
FIG. 2 is a cross-sectional view showing a configuration of a main part of the optical attenuator according to Embodiment 1 of the present invention.
FIG. 3 is a cross-sectional view showing one block of the present embodiment and an optical fiber disposed on top of the block.
FIG. 4 is a cross-sectional view showing the other block of the present embodiment and an optical fiber disposed on top of the other block.
FIG. 5 is a side view showing a relationship between an optical fiber and a reflection unit and a light path according to the present embodiment.
FIG. 6 is a perspective view showing a structure of a mirror unit according to a first example of the embodiment.
FIG. 7 is a cross-sectional view showing a state in which no voltage is applied to the mirror unit according to the present embodiment, and the rotation in the applied state.
FIG. 8 is a diagram showing a reflecting surface and a light path when the tilt mirror according to the first embodiment is rotated.
FIG. 9 is a graph showing a change in attenuation rate with respect to a tilt angle φ.
FIG. 10 is a cross-sectional view showing another example of a reflection block and a light path according to the embodiment;
FIG. 11 is a diagram showing the movement of the shift mirror and its light path according to the second embodiment of the present invention.
FIG. 12 is a perspective view showing a structure of a mirror unit according to the present embodiment.
FIG. 13 is a cross-sectional view showing a structure of a mirror unit according to the present embodiment.
FIG. 14 is a graph showing a change in attenuation rate with respect to a shift amount Δ in the present embodiment.
FIG. 15 is a schematic view showing an optical fiber and a collimating lens at the tip thereof according to each embodiment of the present invention.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 Base 2 Printed circuit board 3 Mirror board | substrate 4, 5 Spacer 6a, 6b Block 7a, 7b ... 8a, 8b ... V-shaped groove 11a, 11b ... 13a, 13b ... Optical fiber 12a, 12b ... 14a, 14b ... Collimating lenses 20, 40 Reflecting units M1, M2 Reflecting surfaces 21a, 21b ... Mirror units 22a, 22b, 24a, 24b ... Electrodes 23a, 23b Spacers 25, 55 Hinges 26, 26a, 26b ... Tilt mirrors 27, 57 Variable voltage source 56 Shift mirror 61a, 61b Collimator

Claims (8)

An optical fiber disposed in the V-shaped groove of a block having a V-shaped groove parallel to the base, and an incident portion that emits light in parallel with the base;
Light having an optical fiber disposed in the V-shaped groove of the block having a V-shaped groove disposed opposite to the incident portion and parallel to the base, and receiving light from the incident portion side An exit having a fiber;
A mirror unit disposed on a side between the incident part and the emission part and including a rotatable tilt mirror;
A tilt mirror controller that continuously changes the tilt angle of the tilt mirror of the mirror unit;
A first reflecting surface that is disposed between the incident part and the emitting part and reflects light from the incident part to the tilt mirror, and reflects light reflected by the tilt mirror toward the emitting part. And a reflection unit having a second reflection surface ,
The mirror unit is
A part of the movable part having a reflective surface formed on the upper surface is connected to the mirror substrate at the hinge part, and has a tilt mirror that rotates around the hinge, and an electrode formed on the mirror substrate,
The tilt mirror control unit is a variable voltage source that applies a voltage between the tilt mirror and an electrode on the mirror substrate, and rotates the tilt mirror by changing the applied voltage. Features an optical attenuator. An optical fiber disposed in the V-shaped groove of a block having a V-shaped groove parallel to the base, and an incident portion that emits light in parallel with the base;
Light that has an optical fiber disposed in the V-shaped groove of a block having a V-shaped groove that is disposed opposite to the incident part and is parallel to the base, and receives light from the incident part side An exit having a fiber;
A mirror unit including a shift mirror disposed on a side between the incident part and the emission part and changing a distance between the incidence part and the emission part;
A shift mirror controller for changing the position of the shift mirror of the mirror unit;
A first reflecting surface that is disposed between the incident portion and the emission portion and reflects light from the incidence portion to the shift mirror, and reflects light reflected by the shift mirror toward the emission portion. And a reflection unit having a second reflection surface,
The mirror unit is
The outer peripheral portion of the movable portion having a reflective surface formed on the upper surface has a shift mirror held on the mirror substrate so as to be movable up and down, and an electrode formed on the mirror substrate.
The shift mirror control unit is a variable voltage source that applies a voltage between the shift mirror and an electrode on the mirror substrate, and rotates the shift mirror by changing the applied voltage. Features an optical attenuator. An optical fiber disposed in the V-shaped groove of a block having a V-shaped groove parallel to the base, and an incident portion that emits light in parallel with the base;
Light that has an optical fiber disposed in the V-shaped groove of a block having a V-shaped groove that is disposed opposite to the incident part and is parallel to the base, and receives light from the incident part side An exit having a fiber;
A mirror unit including a shift mirror disposed on a side between the incident part and the emission part and changing a distance between the incidence part and the emission part;
A shift mirror controller for changing the position of the shift mirror of the mirror unit;
A first reflecting surface that is disposed between the incident portion and the emission portion and reflects light from the incidence portion to the shift mirror, and reflects light reflected by the shift mirror toward the emission portion. And a reflection unit having a second reflection surface,
The mirror unit is
A shift mirror disposed on the substrate and having a reflective surface on the upper surface;
A piezoelectric actuator that is held between the shift mirror and the substrate and moves the shift mirror up and down; and
The shift mirror controller is
An optical attenuator, wherein a voltage is applied to the piezoelectric actuator to move the shift mirror up and down parallel to the surface. The entrance portion and the exit portion, an optical fiber and an optical attenuator according to any one of claims 1-3, characterized in that the lens unit for collimating light emitted from the optical fiber is provided at its front end . The optical attenuator according to claim 4 , wherein the lens unit is a ball lens and is attached to a tip of each optical fiber. The reflection unit is a reflection unit having the first and second reflection surfaces having a V-shaped cross section on the lower surface thereof,
The said 1st reflective surface is formed toward the said incident part, and the said 2nd reflective surface is formed toward the said output part, The any one of Claims 1-3 characterized by the above-mentioned. The optical attenuator described. The reflection unit is a reflection unit composed of a glass block having the first and second reflection surfaces having a V-shaped cross section on the upper surface thereof;
The said 1st reflective surface is formed toward the said incident part, and the said 2nd reflective surface is formed toward the said output part, The any one of Claims 1-3 characterized by the above-mentioned. The optical attenuator described. Optical attenuator array, characterized in that a light attenuator according to any one of claims 1 to 7 to the base in a plurality parallel.

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