JP2000258701A - Optical switching element - Google Patents

Abstract

(57) [Problem] To prevent an operation failure due to electrostatic adsorption and destruction of a peripheral circuit due to electric discharge in an optical switching element which performs optical switching by moving an extraction unit toward and away from a waveguide and coupling the evanescent wave. I do. An optical switching element is provided on a waveguide, a substantially transparent conductive film that is provided on a surface of the waveguide and is grounded, and a reflection that approaches and separates from the waveguide via the conductive film. A prism 3, a prism electrode 5 for moving the reflection prism 3 by electrostatic force, a prism base 4, which is mechanically connected so that the prism electrode 5 and the reflection prism 3 move integrally, a substrate 10, on the substrate 10 The fixed support 9 has one end attached to the support 9 and the other end attached to the prism electrode 5, and includes a cantilever 6 for elastically supporting the reflection prism 3.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an optical switching element for switching light by approaching and moving away from an optical member.

[0002]

2. Description of the Related Art A prior art related to the present invention will be described.

An optical switching element for switching light using evanescent wave coupling as shown in FIGS. 11 and 12 has been proposed. Hereinafter, the operation of the optical switching element will be briefly described with reference to the drawings.

First, a description will be given with reference to FIG. The optical switching element includes a waveguide 1, a reflecting prism 3 approaching and moving away from the waveguide 1, a prism electrode 5 for moving the reflecting prism 3 by electrostatic force, and the prism electrode 5 and the reflecting prism 3 being integrated. The prism base 4, the substrate 10, the support 9 fixed on the substrate 10, which is mechanically connected so as to move, one end is attached to the support 9, and the other end is attached to the prism electrode 5. It comprises a cantilever 6 that elastically supports it. Here, illumination light 11 is supplied to the waveguide 1 from an appropriate light source. The illumination light 11 is substantially parallel light, and light is repeatedly and totally reflected at all interfaces inside the waveguide 1 so that the inside of the waveguide 1 is incident at a constant incident angle such that the inside of the waveguide 1 is filled with light rays. Is set to In this state, the illumination light 11 is macroscopically confined inside the waveguide 1 and propagates through the waveguide 1 without loss. On the other hand, microscopically, in the vicinity of the surface of the waveguide 1 which is totally reflected, the illumination light 11 leaks once from the waveguide 1 by a very small distance of about the wavelength of light, and changes its course. Is returned into the waveguide 1 again. The leaked light is generally called an evanescent wave. The evanescent wave can be extracted by bringing another optical member close to the total reflection surface of the waveguide 1 at a distance of about the wavelength of light or less. That is, if an optically transparent member is approached as the optical member, the optical member can be transmitted and taken out. If an optically reflective member is approached as the optical member, the evanescent wave is reflected. Then, the waveguide 1 can be transmitted and taken out.
Therefore, if the optical member is moved toward and away from the actuator, an operation such as taking out or not taking out the illumination light 11 becomes possible.

[0005] This conventional example is an optical switching element utilizing the above phenomenon. The reflecting prism 3 is initially supported at a mechanical neutral point by the cantilever 6, but when a voltage is applied between the prism electrode 5 and the lower electrode 8, an attractive force due to electrostatic force is applied between the two. Working,
The prism electrode 5 moves downward in the figure. At this time, the reflection prism 3 connected to the prism electrode 5
Move downward, and separate from the waveguide 1. FIG. 11 shows this state. In this state, the illumination light 11 remains confined inside the waveguide 1. This is the optical switching OFF state.

Next, when a voltage is applied between the prism electrode 5 and the upper electrode 7, an attraction force is also exerted between the two by electrostatic force, and the prism electrode 5 moves upward in the drawing. . At this time, the reflection prism 3 connected to the prism electrode 5 also moves upward and approaches the waveguide 1. FIG. 12 shows this state. If the approach distance is sufficiently small, the waveguide 1
The illuminating light 11 leaking out of the optical path reaches the reflecting prism 3 and is reflected, changes its course, and enters the waveguide 1 again. At this time, the angle of the incoming light is no longer
Since the angle is not the angle of total internal reflection, the light penetrates the waveguide 1 as it is, and is emitted as derived light 12 to the outside. This is set to the optical switching ON state.

As described above, in this conventional example, the illumination light 11 is extracted from the waveguide 1 by selectively applying a voltage to each electrode. If a light receiving optical system is installed in the emission direction, the optical system has a configuration that functions as an optical switching element. In addition, a large number of the above configurations are arranged in a matrix to display an image.

[0008]

However, in the conventional optical switching device shown in FIGS. 11 and 12, when the waveguide 1 and the reflecting prism 3 are moved closer to and separated from each other, static electricity is generated between them. There was a fear of doing. Furthermore, the present optical switching element is manufactured in a low-humidity environment in order to prevent adsorption by moisture, and is likely to generate static electricity. In general, since the members such as the waveguide 1 and the reflecting prism 3 are insulative, the charges generated by the generated static electricity cannot move, causing the members to remain on the members and become charged. On the other hand, there is a possibility that static electricity may be generated at any place of the movable part, and in a configuration having a plurality of the reflecting prisms 3, it is also generated between the adjacent reflecting prisms 3.

The charging causes electrostatic attraction of the waveguide 1 and the reflecting prism 3 and causes switching failure. Further, the present optical switching element can be integrally formed on a silicon substrate together with a driving circuit. At this time, when the above-mentioned electric charge exceeds a certain amount, the electric switching element moves at once by discharging, so that the driving circuit becomes large. There is a risk that the current will flow and break down the circuit element. In particular, MOSFETs often used as circuit elements are liable to break down between the gate and the channel, and some measures have been required.

Accordingly, an object of the present invention is to provide an optical switching element having a configuration that prevents the above-described problem of electrostatic attraction and also prevents damage to the drive circuit.

[0011]

(1) An optical switching element according to the present invention comprises: a light guide section having a total reflection surface capable of transmitting an incident light by total reflection; and an evanescent wave to the total reflection surface. A light-transmissive extractor that can move to a first position that is less than or equal to the leaking extraction distance, and a second position that is more than the extraction distance, and driving means for moving the extractor; It is characterized in that one or more layers made of a conductive material are provided on the surface of the light guide section facing the extraction section.

(2) The optical switching element of the present invention is characterized in that, in the first aspect, the one or more layers are grounded.

(3) In the optical switching element according to the first aspect of the present invention, the material of the one or more layers is ITO.

(4) The optical switching element according to the first aspect, wherein the one or more layers are made of a material having a higher refractive index than the light guide section or the extraction section.

(5) The optical switching element of the present invention has a light guide portion provided with a total reflection surface capable of transmitting reflected light by total reflection, and an extraction distance at which an evanescent wave leaks to the total reflection surface. A first position approaching, and a light-transmitting extraction unit movable to a second position separated by more than the extraction distance;
And a driving unit for moving the extraction unit, wherein at least one layer made of a conductive material is provided on a surface of the extraction unit opposite to the light guide unit.

(6) The optical switching element according to the present invention is characterized in that, in the paragraph 5, the one or more layers are grounded.

(7) The optical switching element of the present invention is characterized in that, in paragraph 5, the material of the one or more layers is ITO.

(8) In the optical switching element of the present invention, in the fifth aspect, the one or more layers are made of a material having a higher refractive index than the light guide or the extractor.

(9) The optical switching element of the present invention has a light guide portion having a total reflection surface capable of transmitting the reflected light by total reflection, and an extraction distance within which the evanescent wave leaks to the total reflection surface. A first position approaching, and a light-transmitting extraction unit movable to a second position separated by more than the extraction distance;
And a driving means for moving the extraction section, wherein the light guide section is made of a conductive material.

(10) The optical switching element according to the present invention comprises:
9. The method according to claim 9, wherein the light guide is grounded.

(11) The optical switching element according to the present invention comprises:
A light guide portion having a total reflection surface capable of totally reflecting and transmitting the introduced light, a first position approaching less than an extraction distance at which an evanescent wave leaks to the total reflection surface, and being separated by more than the extraction distance A translucent extraction unit movable to a second position;
Driving means for moving the extraction unit, wherein the extraction unit is made of a conductive material.

(12) The optical switching element of the present invention is:
Item 11 is characterized in that the extraction unit is grounded.

(13) The optical switching element according to the present invention comprises:
A light guide portion having a total reflection surface capable of totally reflecting and transmitting the introduced light, a first position approaching less than an extraction distance at which an evanescent wave leaks to the total reflection surface, and being separated by more than the extraction distance A plurality of light-transmitting extraction units movable to the second position, and a driving unit for moving the extraction units, and furthermore, any or all of the plurality of extraction units facing each other, It is characterized by having one or more layers made of a conductive material.

(14) The optical switching element of the present invention
13. The method of claim 13, wherein the one or more layers are grounded.

(15) The optical switching element according to the present invention comprises:
13. The method according to claim 13, wherein a material of the one or more layers is ITO.

(16) The optical switching element according to the present invention comprises:
A light guide portion having a total reflection surface capable of totally reflecting and transmitting the introduced light, a first position approaching less than an extraction distance at which an evanescent wave leaks to the total reflection surface, and being separated by more than the extraction distance A plurality of light-transmitting extraction parts movable to a second position, a support for supporting the extraction parts, and a driving means for moving the extraction parts; and the support is made of a conductive material. It is characterized by comprising.

(17) The optical switching element according to the present invention comprises:
Item 15 is characterized in that the support is grounded.

(18) The optical switching element of the present invention
A light guide portion having a total reflection surface capable of totally reflecting and transmitting the introduced light, a first position approaching less than an extraction distance at which an evanescent wave leaks to the total reflection surface, and being separated by more than the extraction distance A translucent extraction unit movable to a second position;
A reflecting surface that reflects the extracted light extracted by the extracting unit;
Driving means for moving the extraction unit, and the reflection surface is conductive.

(19) The optical switching element of the present invention
Item 18 is characterized in that the reflection surface is grounded.

[0030]

(Embodiment 1) An embodiment of the present invention will be described below with reference to the drawings.

FIGS. 1 and 2 are explanatory views showing the structure of an optical switching element according to one embodiment of the present invention.

First, a description will be given with reference to FIG. The optical switching element includes a waveguide 1, a substantially transparent conductive film 2 provided on the surface of the waveguide 1, a reflecting prism 3 approaching and separating from the waveguide 1 via the conductive film 2, and a reflecting prism. A prism electrode 5 for moving the prism electrode 3 by electrostatic force; a prism base 4 for mechanically connecting the prism electrode 5 and the reflection prism 3 so as to move integrally; a substrate 10;
The support 9 is fixed on the support 0, one end is attached to the support 9, and the other end is attached to the prism electrode 5, and is constituted by a cantilever 6 for elastically supporting the reflection prism 3. The conductive film 2 is electrically connected to any one of the upper electrode 7, the lower electrode 8, and the prism electrode 5 so as to have the same potential. The conductive film 2
The material of the IT
O, IT, IO, SnO ₂ or the like may be used. Alternatively, the use of diamond-like carbon made conductive by nitrogen has a great effect in preventing adsorption by moisture.

The waveguide 1 is supplied with illumination light 11 from an appropriate light source. The illumination light 11 is substantially parallel light, and light is repeatedly and totally reflected at all interfaces inside the waveguide 1 so that the inside of the waveguide 1 is incident at a constant incident angle such that the inside of the waveguide 1 is filled with light rays. Is set to In this state, the illumination light 11 is macroscopically confined inside the waveguide 1 and propagates through the waveguide 1 without loss. On the other hand, microscopically, in the vicinity of the surface of the waveguide 1 which is totally reflected, the illumination light 11 leaks once from the waveguide 1 by a very small distance of about the wavelength of light, and changes its course. Is returned into the waveguide 1 again. The leaked light is generally called an evanescent wave. The evanescent wave can be extracted by bringing another optical member close to the total reflection surface of the waveguide 1 at a distance of about the wavelength of light or less. That is,
If a light transmissive member is approached as the optical member, the optical member can be transmitted and taken out.If a light reflective member is approached as the optical member, the evanescent wave is reflected. The light can be extracted through the waveguide 1. Therefore, if the optical member is moved toward and away from the actuator, an operation such as taking out or not taking out the illumination light 11 becomes possible.

The present embodiment is an optical switching element utilizing the above phenomenon. The reflecting prism 3 is initially supported at a mechanical neutral point by the cantilever 6, but when a voltage is applied between the prism electrode 5 and the lower electrode 8, an attractive force due to electrostatic force is applied between the two. Working,
The prism electrode 5 moves downward in the figure. At this time, the reflection prism 3 connected to the prism electrode 5
Move downward, and separate from the waveguide 1. FIG. 1 shows this state. In this state, the illumination light 11 remains confined inside the waveguide 1. This is the optical switching OFF state.

Next, when a voltage is applied between the prism electrode 5 and the upper electrode 7, an attraction force is also exerted between the two by electrostatic force, and the prism electrode 5 moves upward in the drawing. . At this time, the reflection prism 3 connected to the prism electrode 5 also moves upward and approaches the waveguide 1. FIG. 2 shows this state. If the approach distance is sufficiently small, the illumination light 11 leaked from the waveguide 1 reaches the reflecting prism 3 via the conductive film 2 and is reflected, and then enters the waveguide 1 again after changing its course. I do. At this time, since the angle of the incoming light is no longer the angle of total reflection inside the waveguide 1, it penetrates the waveguide 1 as it is, and exits as derived light 12 to the outside. This is optical switching O
N state.

As described above, in the optical switching element of this embodiment, the illumination light 11 is extracted from the waveguide 1 by selectively applying a voltage to each electrode. If a light receiving optical system is provided in the emission direction, it has a configuration that functions as an optical switching element. Further, an image may be displayed by arranging a large number of the above configurations in a matrix.

In the conventional optical switching element, when the waveguide 1 and the reflection prism 3 are moved closer to each other and separated from each other, there is a phenomenon that static electricity is generated between the waveguides 1 and the reflection prism 3 to charge them. The charging not only caused electrostatic attraction of the waveguide 1 and the reflecting prism 3 and caused a switching failure, but also caused a risk of destruction of elements of the drive circuit due to discharge. However, in the optical switching element of the present embodiment, even if static electricity is generated on the surface of the waveguide 1, the charge can move freely due to the presence of the conductive film 2, and the conductive film 2 can be moved to the upper electrode 7 or Since it is electrically connected to either the lower electrode 8 or the prism electrode 5 so as to have the same potential, the charge flows away and is not accumulated. Therefore, the above-described electrostatic attraction does not occur, and damage to the drive circuit can be prevented.

Further, the conductive film 2 has another beneficial effect. This will be described below.

In the conventional optical switching element to which the above-described evanescent wave coupling is applied, the intensity of the evanescent wave oozing out of the waveguide 1 exponentially attenuates exponentially with respect to the distance. There is a problem that the waveguide 1 and the reflecting prism 3 must be sufficiently close to each other to take out. However, in practice, it is difficult to always achieve a sufficient and uniform approach because there are manufacturing errors, surface roughness, and variations in distance when a plurality of the reflecting prisms 3 are arranged. As a result, there is a possibility that a sufficient amount of light cannot be obtained or a large variation occurs in the amount of light.

However, as shown below, the structure having the conductive film 2 as in the present embodiment, and using a material having a higher refractive index than the waveguide 1 or the reflecting prism 3 as the material, Can improve the problem. This is shown in FIG. Curve 13 which is a solid line
In the case where the conductive film 2 is not provided, the dotted line curve 14 indicates a change in the amount of light P extracted from the waveguide 1 with respect to the distance x between the waveguide 1 and the reflective prism 3 when the conductive film 2 is provided. It is shown. First, the conductive film 2
When there is no light quantity, the quantity of light extracted is maximum when the distance is 0, and shows a sharp peak. Then, it decreases monotonously rapidly as the distance increases. On the other hand, the conductive film 2
In the case where there is a curve, the curve has a gentle peak at a certain distance and gradually decreases. It should be particularly noted that in the range of a certain distance x1 to x2, the amount of light extracted is larger than in the case where the conductive film 2 is not provided. That is, in the optical switching element, even if the waveguide 1 and the reflecting prism 3 are not sufficiently close to each other due to an error, surface roughness, variation, or the like, not only is the degree of output reduction suppressed but also increased. Indicates that it can be done. Further, as described above, since the curve at the peak portion becomes gentle, the waveguide 1
Also, the variation in the amount of light taken out even with the variation in the distance between the reflection prism 3 and the reflection prism 3 is reduced. In other words, it is possible to increase the margin for the variation in distance.
This is effective in suppressing unevenness in brightness between pixels when an image display device or the like is configured by arranging a large number of optical switching elements of this embodiment in an array or a matrix.

Here, by setting the thickness of the conductive film 2 to an appropriate value, it is possible to maximize the amount of light that can be taken out at a target distance or minimize the variation with respect to the distance. This is shown in FIG. In the figure, a curve 13 represents the case where the conductive film 2 is not provided, and a curve 15 represents a case where the optical thickness of the conductive film 2 is 1/30 of the wavelength.
Is a case where the optical thickness of the conductive film 2 is 1/8 of the wavelength, and a curve 17 is a case where the optical thickness of the conductive film 2 is 1/3 of the wavelength. Here, the optical thickness is obtained by multiplying the physical thickness, that is, the actual size, by the refractive index. Due to the addition of the conductive film 2, the curve of the amount of light taken out changes from a high and sharp peak at a distance of 0 to a gradually decreasing curve having a gentle peak at a certain distance. FIG.
As can be seen, when the thickness of the conductive film 2 is changed, the shape of the curve also changes. That is, the curve 1 when the optical thickness of the conductive film 2 is 1/30 of the wavelength.
In No. 5, the peak shifts and becomes slower than the curve 13 in the case where the conductive film 2 is not present, and the peak value decreases. In the case of the curve 16 in which the optical thickness of the conductive film 2 is １ ／ of the wavelength, the peak is shifted and dulled and the peak value is further reduced with respect to the curve 15. In the curve 17 in which the optical thickness of the conductive film 2 is 1/3 of the wavelength, the curve shape near the peak becomes extremely gentle, and the light amount decreases as a whole. Comparing the above curves, the curve 11 has the maximum light amount from the distance 0 to x0, which is the most advantageous. Similarly, curve 15 is most advantageous from distance x0 to x1, and curve 16 from distance x1 to x2. Therefore, when actually manufacturing or manufacturing an optical switching element, the distance between the waveguide 1 and the reflecting prism 3 and its error, the roughness of the boundary surface,
By selecting an appropriate thickness of the conductive film 2 due to variations or the like, light can be extracted most efficiently.
According to FIG. 4, in consideration of the generally expected distance between the waveguide 1 and the reflecting prism 3 and its error, roughness of the boundary surface, and variation, the optical thickness of the conductive film 2 is 1/30 of the wavelength. Suitably, any value between 1/3 is used.

In this embodiment, the reflecting prism 3 is moved closer to the waveguide 1, the leaked evanescent light is reflected by the reflecting prism 3, and the reflected evanescent light passes through the waveguide 1 and is taken out. However, the structure of the optical switching element using the evanescent wave coupling can be variously considered. For example, if all or any of the components in FIG.
An optical switching element that transmits and extracts the evanescent light can be formed on the side. In any of these optical switching elements, if the conductive film 2 having an appropriate thickness as shown in the present embodiment is inserted into the boundary surface where the evanescent wave coupling is performed, the same as in the present embodiment. Effect, ie, malfunction due to electrostatic attraction,
It is needless to say that an optical switching element can be obtained in which there is no fear of destruction of the peripheral circuit and light can be efficiently extracted with less variation in the amount of light.

(Embodiment 2) FIG. 5 is an explanatory view showing a configuration of an optical switching element according to an embodiment of the present invention, showing an optical switching OFF state.

In the first embodiment, the conductive film 2
Is provided to prevent charging, but the conductive film 2 may be provided on the reflection prism 3 side in the same manner.

The operation will be described with reference to FIG. The optical switching element includes a waveguide 1, a reflecting prism 3 approaching and separating from the waveguide 1, a substantially transparent conductive film 2 provided on a surface of the reflecting prism 3 facing the waveguide 1, and the reflecting prism. A prism electrode 5 for moving the prism electrode 3 by electrostatic force; a prism base 4 for mechanically connecting the prism electrode 5 and the reflection prism 3 so as to move integrally; a substrate 10; a support 9 fixed on the substrate 10; One end is attached to the support 9 and the other end is attached to the prism electrode 5. The cantilever 6 elastically supports the reflection prism 3. The conductive film 2 is electrically connected to any one of the upper electrode 7, the lower electrode 8, and the prism electrode 5 so as to have the same potential. The material of the conductive film 2 is IT which is often used for a transparent electrode.
O, IT, IO, SnO ₂ or the like may be used. Alternatively, the use of diamond-like carbon made conductive by nitrogen has a great effect in preventing adsorption by moisture.

In the optical switching element of this embodiment, even if static electricity is generated on the surface of the reflecting prism 3, the electric charge can move freely due to the presence of the conductive film 2. Further, the conductive film 2 7 or the lower electrode 8 or the prism electrode 5 is electrically connected to any of them so as to have the same potential, so that the electric charge flows away and is not accumulated. Therefore, the above-described electrostatic attraction does not occur, and damage to the drive circuit can be prevented.

The other configurations and effects are the same as those of the first embodiment, and a detailed description thereof will be omitted.

(Embodiment 3) FIG. 6 is an explanatory view showing a configuration of an optical switching element according to an embodiment of the present invention, showing an optical switching OFF state.

In the first embodiment, the configuration is described in which the conductive film 2 is provided on the waveguide 1 to prevent charging, but the waveguide 1 itself may be made conductive.

The operation will be described with reference to FIG. The optical switching element includes a waveguide 1 having conductivity, a reflecting prism 3 approaching and separating from the waveguide 1, a prism electrode 5 for moving the reflecting prism 3 by electrostatic force, the prism electrode 5 and the reflecting prism. A prism base 4, a substrate 10, a support 9 fixed on the substrate 10, one end of which is attached to the support 9, and another end of which is attached to the prism electrode 5; It comprises a cantilever 6 which elastically supports the reflecting prism 3. The waveguide 1 is electrically connected to either the upper electrode 7, the lower electrode 8, or the prism electrode 5 so as to have the same potential.

In the optical switching element of the present embodiment, even if static electricity is generated on the surface of the reflecting prism 3, charges can move freely inside the waveguide 1, and the waveguide 1 is connected to the upper electrode 7 Alternatively, since the electric charges are electrically connected to either the lower electrode 8 or the prism electrode 5 so as to have the same potential, the electric charge flows away and is not accumulated. Therefore, the above-described electrostatic attraction does not occur, and damage to the drive circuit can be prevented.

Other configurations and effects are the same as those of the first embodiment, and a detailed description thereof will be omitted.

(Embodiment 4) FIG. 7 is an explanatory view showing the configuration of an optical switching element according to an embodiment of the present invention, showing an optical switching OFF state.

In the second embodiment, the structure in which the conductive film 2 is provided on the reflection prism 3 to prevent charging is shown. However, the reflection prism 3 itself may be made conductive.

A description will be given with reference to FIG. The optical switching element includes a waveguide 1, a conductive reflecting prism 3 approaching and separating from the waveguide 1, a prism electrode 5 for moving the reflecting prism 3 by electrostatic force, and the prism electrode 5 and the reflecting prism 3. The prism base 4, the substrate 10, the support 9 fixed on the substrate 10, one end of which is attached to the support 9, and the other end of which is attached to the prism electrode 5, and the reflection It comprises a cantilever 6 that elastically supports the prism 3. The reflection prism 3 is electrically connected to any one of the upper electrode 7 or the lower electrode 8 or the prism electrode 5 so as to have the same potential.

In the optical switching element of this embodiment, even if static electricity is generated on the surface of the reflection prism 3, the charge can move freely inside the reflection prism 3 and the reflection prism 3 is connected to the upper electrode 7 Alternatively, since the electric charges are electrically connected to either the lower electrode 8 or the prism electrode 5 so as to have the same potential, the electric charge flows away and is not accumulated. Therefore, the above-described electrostatic attraction does not occur, and damage to the drive circuit can be prevented.

The other configurations and effects are the same as those of the first embodiment, and a detailed description thereof will be omitted.

(Embodiment 5) FIG. 8 is an explanatory diagram showing the configuration of an optical switching element according to an embodiment of the present invention.

The static electricity may be generated at any part of the movable part, and may be charged at other parts. For example, in a configuration having a plurality of the reflecting prisms 3, static electricity is generated even between the adjacent reflecting prisms 3. An optical switching element having a configuration for preventing this will be described.

A description will be given based on FIG. The optical switching element includes a waveguide 1, a reflecting prism 3 approaching and separating from the waveguide 1, a conductive film 2 provided on a side surface of the reflecting prism 3, and a prism electrode for moving the reflecting prism 3 by electrostatic force. 5, a prism base 4, which mechanically connects the prism electrode 5 and the reflecting prism 3 so as to move integrally, a substrate 10, a support 9 fixed on the substrate 10, one end of the support 9 and the other end of the support 9 Is mounted on the prism electrode 5 and comprises a cantilever 6 for elastically supporting the reflection prism 3. . The conductive film 2
Are electrically connected to the upper electrode 7 or the lower electrode 8 or the prism electrode 5 so as to have the same potential. In this embodiment, the conductive film 2 does not need to be transparent, and may be a metal, a carbon-based material, or a material mixed with a powder.

In the optical switching element of this embodiment, even if static electricity is generated on the surfaces of the adjacent reflecting prisms 3, charges can move freely due to the presence of the conductive film 2. Is electrically connected to either the upper electrode 7 or the lower electrode 8 or the prism electrode 5 so as to be at the same potential as that of the upper electrode 7, the lower electrode 8, or the prism electrode 5. Therefore, an operation failure due to electrostatic attraction between the adjacent reflection prisms 3 does not occur, and damage to the drive circuit can be prevented.

The other configurations and effects are the same as those of the first embodiment, and a detailed description thereof will be omitted.

(Embodiment 6) FIG. 9 is an explanatory view showing the configuration of an optical switching element according to an embodiment of the present invention.

By making the prism base 4 conductive, in a configuration having a plurality of the reflecting prisms 3 as in the fifth embodiment, generation of static electricity between the adjacent reflecting prisms 3 is prevented. An optical switching element having such a configuration will be described.

The operation will be described with reference to FIG. The optical switching element includes a waveguide 1, a reflecting prism 3 approaching and moving away from the waveguide 1, a prism electrode 5 for moving the reflecting prism 3 by electrostatic force, and the prism electrode 5 and the reflecting prism 3 being integrated. A prism base 4, a substrate 10, a support 9 fixed on the substrate 10, having one end attached to the support 9 and the other end attached to the prism electrode 5; It comprises a cantilever 6 which elastically supports the reflecting prism 3. The prism base 4 is provided with an upper electrode 7 or a lower electrode 8.
Alternatively, it is electrically connected to any of them so as to have the same potential as the prism electrode 5. In this embodiment, the conductive film 2 does not need to be transparent, and may be a metal, a carbon-based material, or a material mixed with a powder.

In the optical switching device of this embodiment, even if static electricity is generated on the surfaces of the adjacent reflecting prisms 3, the charges can move freely inside the prism base 4, and the prism base 4 is Since it is electrically connected to either the upper electrode 7 or the lower electrode 8 or the prism electrode 5 so as to have the same potential, the charge flows away and is not accumulated. Therefore, an operation failure due to electrostatic attraction between the adjacent reflection prisms 3 does not occur, and damage to the drive circuit can be prevented.

The other configurations and effects are the same as those of the first embodiment, and a detailed description thereof will be omitted.

(Embodiment 7) FIG. 10 is an explanatory view showing the configuration of an optical switching element according to an embodiment of the present invention.

The reflecting prism 3 may have a reflecting film on its reflecting surface, but an optical switching element having a structure in which the reflecting film is made of a conductive material to prevent charging around the reflecting prism 3. Will be described.

The operation will be described with reference to FIG. The optical switching element includes a waveguide 1, a reflecting prism 3 approaching and separating from the waveguide 1, a reflecting film 18 provided on a reflecting surface of the reflecting prism 3, and a prism for moving the reflecting prism 3 by electrostatic force. An electrode 5, a prism base 4, which mechanically connects the prism electrode 5 and the reflection prism 3 so as to move integrally, a substrate 10, a support 9 fixed on the substrate 10, one end of the support 9 and another support 9; One end is attached to the prism electrode 5 and comprises a cantilever 6 for elastically supporting the reflection prism 3. The reflection film 18 is electrically connected to any one of the upper electrode 7, the lower electrode 8, and the prism electrode 5 so as to have the same potential. In this embodiment, the conductive film 2 does not need to be transparent, and may be a metal, a carbon-based material, or a material mixed with a powder.

In the optical switching element of this embodiment, even if static electricity is generated around the reflection prism 3, the charge can move freely because the reflection film 18 is conductive. Since the electrode 7 or the lower electrode 8 or the prism electrode 5 is electrically connected to any of them so as to have the same potential, the charge flows away and is not accumulated. Therefore, no malfunction occurs due to electrostatic attraction between the adjacent reflection prisms 3 and damage to the drive circuit can be prevented.

The other configurations and effects are the same as those of the first embodiment, and a detailed description thereof will be omitted.

[0073]

According to the present invention, the following effects can be obtained.

(1) In the optical switching element of the present invention, since the conductive film is provided on the waveguide or the extraction portion or the prism base and grounded, even if static electricity is generated on the surface thereof, the electric charge flows away. It is not accumulated. Therefore, charging between the waveguide 1 and the reflecting prism 3 or between the reflecting prisms causes electrostatic attraction as seen in a conventional optical switching element, thereby causing switching failure or causing the driving by discharge. Breakage of circuit elements can be prevented. Further, if diamond-like carbon containing nitrogen or the like is used as the material of the conductive film, adsorption by moisture can be prevented. Also, if the thickness of the conductive film is an appropriate value,
An optical switching element that can extract light efficiently with little variation in the amount of light can be obtained.

(2) In the optical switching element of the present invention, since the waveguide, the extraction portion, or the prism base is made conductive and grounded, even if static electricity is generated in the optical switching element, the electric charge flows away. It is not accumulated. Therefore, it is possible to prevent the occurrence of switching failure or the destruction of the elements of the drive circuit due to the discharge, which are caused by the electrostatic attraction, which is observed in the conventional optical switching elements due to charging.

(3) In the optical switching element of the present invention, the reflection film of the extraction part is made conductive and grounded,
Even if static electricity is generated around the reflection prism, the charge flows away and is not accumulated. Therefore, it is possible to prevent electrostatic attraction caused by charging between the reflecting prisms, which is observed in a conventional optical switching element, causing switching failure, and preventing the elements of the drive circuit from being damaged by discharging. be able to.

[Brief description of the drawings]

FIG. 1 is an explanatory view showing one embodiment of an optical switching element of the present invention.

FIG. 2 is an explanatory view showing one embodiment of the optical switching element of the present invention.

FIG. 3 is an explanatory diagram for explaining an embodiment of the optical switching element of the present invention.

FIG. 4 is an explanatory diagram for explaining an embodiment of the optical switching element of the present invention.

FIG. 5 is an explanatory view showing another embodiment of the optical switching element of the present invention.

FIG. 6 is an explanatory view showing another embodiment of the optical switching element of the present invention.

FIG. 7 is an explanatory view showing another embodiment of the optical switching element of the present invention.

FIG. 8 is an explanatory view showing another embodiment of the optical switching element of the present invention.

FIG. 9 is an explanatory view showing another embodiment of the optical switching element of the present invention.

FIG. 10 is an explanatory view showing another embodiment of the optical switching element of the present invention.

FIG. 11 is an explanatory view showing an example of a conventional optical switching element.

FIG. 12 is an explanatory view showing an example of a conventional optical switching element.

[Explanation of symbols]

REFERENCE SIGNS LIST 1 waveguide 2 conductive film 3 reflecting prism 4 prism base 5 prism electrode 6 cantilever 7 upper electrode 8 lower electrode 9 support 11 substrate 11 illumination light 12 derived light 13 curve without intermediate layer 14 curve with intermediate layer 15 Curve when the optical thickness of the conductive film is 1/30 of the wavelength of light 16 Curve when the optical thickness of the conductive film is 1/8 of the wavelength of light 17 When the optical thickness of the conductive film is Curve for 1/3 wavelength 18 Reflective film

Claims (19)

[Claims] 1. A light guide section having a total reflection surface capable of transmitting reflected light by total reflection, a first position approaching the extraction distance at which an evanescent wave leaks to the total reflection surface, and A light-transmitting extraction unit movable to a second position separated by more than the extraction distance, and a driving unit for moving the extraction unit, and a conductive surface is provided on a surface of the light guide unit facing the extraction unit. An optical switching element comprising one or more layers made of a material. 2. The optical switching device according to claim 1, wherein said one or more layers are grounded. 3. The optical switching element according to claim 1, wherein the material of said one or more layers is ITO. 4. The optical switching element according to claim 1, wherein said one or more layers are made of a material having a higher refractive index than said light guide section or said extraction section. 5. A light guide section having a total reflection surface capable of transmitting the introduced light by total reflection, a first position approaching the extraction distance at which an evanescent wave leaks to the total reflection surface, and A light-transmitting extraction unit movable to a second position separated by more than the extraction distance, and driving means for moving the extraction unit, and a conductive surface is provided on a surface of the extraction unit opposite to the light guide unit. An optical switching element comprising one or more layers made of a material. 6. The optical switching device according to claim 5, wherein said one or more layers are grounded. 7. The optical switching element according to claim 5, wherein the material of said one or more layers is ITO. 8. The optical switching element according to claim 5, wherein said one or more layers are made of a material having a higher refractive index than said light guide section or said extraction section. 9. A light guide section provided with a total reflection surface capable of transmitting reflected light by total reflection, a first position approaching the extraction distance at which an evanescent wave leaks to the total reflection surface, and It has a translucent extraction part movable to a second position separated by more than the extraction distance, and a driving means for moving the extraction part, wherein the light guide part is made of a conductive material. Optical switching element. 10. The optical switching element according to claim 9, wherein said light guide is grounded. 11. A light guide section having a total reflection surface capable of transmitting the introduced light by total reflection, a first position approaching the extraction distance at which an evanescent wave leaks to the total reflection surface, and A light-transmitting extraction part movable to a second position separated by more than the extraction distance; and a driving means for moving the extraction part, wherein the extraction part is made of a conductive material. Switching element. 12. The optical switching device according to claim 11, wherein said extraction unit is grounded. 13. A light guide section having a total reflection surface capable of transmitting the reflected light by total reflection, a first position approaching the extraction distance at which an evanescent wave leaks to the total reflection surface, and A plurality of light-transmitting extraction units that can be moved to a second position that is longer than the extraction distance, and a driving unit that moves the extraction units; An optical switching element comprising at least one of at least one layer made of a conductive material. 14. The optical switching device according to claim 13, wherein said one or more layers are grounded. 15. The optical switching element according to claim 13, wherein a material of said one or more layers is ITO. 16. A light guide section having a total reflection surface capable of transmitting reflected light by total reflection, a first position approaching the extraction distance at which an evanescent wave leaks to the total reflection surface, and A plurality of light-transmitting extraction units movable to a second position separated by an extraction distance or more, a support table for supporting the extraction units, and driving means for moving the extraction units; Is an optical switching element made of a conductive material. 17. The optical switching device according to claim 16, wherein said support base is grounded. 18. A light guide section having a total reflection surface capable of transmitting the introduced light by total reflection, a first position approaching the extraction distance at which an evanescent wave leaks to the total reflection surface, and A light-transmitting extraction unit movable to a second position separated by more than the extraction distance, a reflection surface that reflects the extracted light extracted by the extraction unit, and a driving unit that moves the extraction unit; Further, the reflection surface is electrically conductive. 19. The optical switching element according to claim 18, wherein said reflection surface is grounded.