JP3668937B2 - Light switch - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to an optical switch, and more particularly to an optical switch that is fixed to a substrate 1 with a difference in height between an outgoing side optical fiber and an incident side optical fiber that receives reflected light from a mirror.
[0002]
[Prior art]
A prior example of a 2 × 2 optical switch in which four mirrors are formed on the surface of a movable electrode plate, and the direction of light emitted from the emission side optical fiber is switched and transmitted to the incidence side optical fiber with reference to FIG. explain.
FIG. 5 is a diagram for explaining the assembled 2 × 2 optical switch. FIG. 5A is a view of the 2 × 2 optical switch as viewed from above, and FIG. 5B is a vertical cross section passing through the axes of the incident side optical fiber 5 and the outgoing side optical fiber 4 ′ in FIG. FIG.
[0003]
The microlenses 91 and 92 constitute the microlens array 9 by cutting out two adjacent microlenses from a flat microlens array in which a large number of lens portions are arranged in a matrix on a transparent flat plate. The output side optical fiber 4 is disposed opposite to the micro lens 91 of the micro lens array 9, and the incident side optical fiber 5 is disposed opposite to the micro lens 92. Similarly, the incident side optical fiber 5 ′ is disposed opposite to the micro lens 91 ′ of the micro lens array 9 ′, and the emission side optical fiber 4 ′ is disposed opposite to the micro lens 92 ′.
[0004]
This 2 × 2 optical switch includes four optical fibers composed of two output-side optical fibers 4, 4 ′ and two incident-side optical fibers 5, 5 ′, and 4 arranged to face these optical fibers. Microlenses 91, 92, 91 ′, 92 ′, movable electrode plate 2, mirrors 31, 32, 31 ′, 32 ′ formed on movable electrode plate 2, and fixed electrode substrate bonded and fixed to movable electrode plate 2 It consists of eight. The movable electrode plate 2 is coupled and held to the substrate 1 via the flexure portion 21. In these optical fibers, one output-side optical fiber 4 and one incident-side optical fiber 5 ′ are arranged to face each other on one of two parallel straight lines, and one on the other straight line. The output side optical fiber 4 ′ and one incident side optical fiber 5 are arranged to face each other. Further, a mirror formed on the movable electrode plate 2 between the opposed emission side optical fiber 4 and the incident side optical fiber 5 ′ and between the emission side optical fiber 4 ′ and the incident side optical fiber 5 so as to face the optical fiber. Is arranged. Further, the respective condensing microlenses are arranged immediately before the respective outgoing-side optical fibers 4, 4 ′ and incident-side optical fibers 5, 5 ′. A mirror formed on the movable electrode plate 2 is positioned between the lenses.
[0005]
The switching operation of the 2 × 2 optical switch will be described with reference to FIG. In the 2 × 2 optical switch, in the steady state shown in FIG. 6A and FIG. 6B, the light incident through the output side optical fiber 4 is reflected by the mirror 31 and the mirror 32 to be incident side light. Although it enters the fiber 5, it is blocked by the mirror 31 and does not enter the other incident side optical fiber 5 ′. On the other hand, the light incident through the output side optical fiber 4 ′ is reflected by the mirror 31 ′ and the mirror 32 ′ and enters the incident side optical fiber 5 ′, but is blocked by the mirror 31 ′ and enters the incident side optical fiber 5. Not incident. In the driving state shown in FIGS. 6C and 6D in which a voltage is applied between the movable electrode plate 2 and the fixed electrode substrate 8 and the movable electrode plate 2 is sucked downward, the output side optical fiber 4 is used. The incident light passes straight above the mirror 31 and the mirror 32 ′ and enters the incident side optical fiber 5 ′, but does not enter the incident side optical fiber 5. On the other hand, the light incident through the output-side optical fiber 4 ′ passes straight above the mirror 31 ′ and the mirror 32 and enters the incident-side optical fiber 5, but does not enter the incident-side optical fiber 5 ′. As described above, the 2 × 2 optical switch can switch the direction of the light emitted from the emission side optical fibers 4 and 4 ′ and transmit the light to the incidence side optical fibers 5 and 5 ′.
[0006]
Here, a method of configuring the mirrors 31, 32, 31 ′, and 32 ′ on the upper surface of the movable electrode plate 2 will be described with reference to FIG.
Referring to FIG. 7A, a photosensitive synthetic resin E having a thickness of several tens of μm is applied to the entire surface of the substrate 1.
Referring to FIG. 7 (b), the mirror shape m is obtained by exposing L from the top only where the mirrors 31, 32, 31 ′ and 32 ′ of the photosensitive synthetic resin E are to be formed by vertical hatching. Constitute.
[0007]
Referring to FIG. 7C, the photosensitive synthetic resin E that is not exposed by development is removed.
Referring to FIG. 7 (d), the mirror shape m is coated with metal to form mirrors 31, 32, 31 ′, 32 ′ having a height of several hundreds of μm (the details are described above by the applicant of the present application). (See Japanese Patent Application No. 2000-270621 concerning the application).
[0008]
[Problems to be solved by the invention]
As described above, the mirrors 31, 32, 31 ′, and 32 ′ are formed by exposing and developing the photosensitive synthetic resin E formed on the surface of the substrate 1 to be the movable electrode plate 2 later as a raw material. In this case, referring to FIG. 7 (e), these mirror bases m are formed so as to be slightly inclined, with their opposing optical fiber side surfaces not formed at a right angle with respect to the surface of the substrate 1. There is a case. That is, the surface of the mirror base m tends to be formed with a gradually decreasing thickness as it approaches the substrate 1. This is because when the photosensitive synthetic resin E mirrors 31, 32, 31 ′, 32 ′ having a thickness of several tens of μm are exposed from above, the surface of the photosensitive synthetic resin E is exposed in the thickness direction. This is probably because a gradient occurs. Here, when the surface facing the optical fiber side of the mirror base m is formed so as to be inclined at an acute angle or an obtuse angle as viewed from the surface of the substrate 1, the surface of the mirror 31, 31 ′ formed by coating a metal Light incident through the exit side optical fibers 4 and 4 ′ and the respective lenses is reflected on the surface of the mirrors 31 and 31 ′ with a slight component in the height direction of the mirrors. That is, when the mirror surface is formed with an acute angle as viewed from the surface of the substrate 1, the incident light is reflected with a slight downward inclination from the surface of the mirror. Therefore, when the emission side optical fibers 4 and 4 ′ and the incidence side optical fibers 5 and 5 ′ are positioned and fixed on a common plane, the optical axis of the reflected light and the optical axis of the incidence side optical fibers 5 and 5 ′ are changed. It is not parallel, and the reflected light is incident on the incident side port with a height difference, which means that proper incidence is made on the respective lenses of the incident side optical fibers 5 and 5 ′. After all, an optical insertion loss due to the 2 × 2 optical switch occurs.
[0009]
The present invention provides an optical switch that solves the above-described problems by providing a difference in height between an outgoing side optical fiber and an incident side optical fiber that receives light reflected by a mirror, and fixing it to a substrate.
[0010]
[Means for Solving the Problems]
Claim 1: The fixed electrode substrate 8, the substrate 1, and the movable electrode plate 2 attached and coupled to the substrate 1 through the flexure portion 21 are adjacent to the movable electrode plate 2 along adjacent straight lines parallel to each other. Are formed on the surface of the movable electrode plate 2 so as to face the emission side optical fiber 4 and the incidence side optical fiber 5 arranged along the straight lines parallel to each other. The mirror pairs 31, 32 are arranged perpendicularly to the substrate 1 with their reflecting surfaces inclined with respect to the linear direction along the straight lines parallel to each other. In an optical switch that controls the light by electrostatically driving 2 downward ,
The light level when the light reaches the incident side optical fiber 5 is emitted from the output side optical fiber 4 between the output side optical fiber 4 and the incident side optical fiber 5 that receives the reflected light from the mirror pairs 31 and 32. An optical switch fixed to the substrate 1 was configured with a difference in height corresponding to the reduced level compared to the light level at that time .
[0011]
Then, according to claim 2 in the optical switch as described in claim 1, the second input side optical fiber 5 'at a position facing each other across the mirror 31 along a straight line emission-side optical fiber 4 is arranged such The optical switch fixed to the board | substrate 1 was made without making a height difference between the output side optical fibers 4 .
Further, the fixed electrode substrate 8, the substrate 1, and the movable electrode plate 2 attached and coupled to the substrate 1 through the flexure portion 21 are adjacent to the movable electrode plate 2 along straight lines parallel to each other. A first pair of mirrors 31 and 32 formed on the surface of the movable electrode plate 2 so as to face the first emission side optical fiber 4 and the first incidence side optical fiber 5 arranged in the first and second mirrors, The pairs 31 and 32 are installed perpendicularly to the substrate with the reflecting surfaces inclined with respect to the linear direction along the straight lines parallel to each other, and the first emission side optical fiber 4 and the first incident side. A second exit-side optical fiber 4 ′ and a second entrance-side optical fiber 5 ′ having the same configuration as the side optical fiber 5, and the first exit-side optical fiber 4 and the second entrance-side optical fiber. Arranged along the same straight line as 5 'and parallel to each other A second pair of mirrors 31 ′ and 32 ′ formed on the surface of the movable electrode plate 2 so as to face the second output-side optical fiber 4 ′ and the second input-side optical fiber 5 ′. The two mirror pairs 31 ′ and 32 ′ are installed perpendicularly to the substrate 1 with their reflecting surfaces inclined with respect to the linear direction along the mutually parallel straight lines, and the movable electrode plate 2 is electrostatically driven downward. In an optical switch that controls switching of light,
The first and second incident-side optical fibers that receive the reflected light from the first and second emission-side optical fibers 4 and 4 ′ and the first and second mirror pairs 31, 32 and 31 ′ and 32 ′. Between the two, the light level when the light reaches the first and second incident-side optical fibers 5 and 5 ′ is emitted from the first and second output-side optical fibers 4 and 4 ′. An optical switch fixed to the substrate 1 was configured with a difference in height corresponding to the amount of reduction compared to the level of .
[0012]
Further, in the optical switch according to any one of claims 1 to 3, a V-shaped cross section is separately formed in the substrate 1 along straight lines parallel to each other to emit light on the emission side. The optical fiber and the incident side optical fiber are positioned and fixed. Here, the height difference between the output side optical fiber and the incident side optical fiber is an optical switch formed by making a difference in the depth of the V-shaped cross section of both. did.
According to a fifth aspect of the present invention, in the optical switch according to any one of the first to fourth aspects, the mirror is formed by coating a metal on the surface of a structure formed by exposing and developing a photosensitive synthetic resin. An optical switch consisting of
[0013]
DETAILED DESCRIPTION OF THE INVENTION
An embodiment of the present invention will be described with reference to the examples of FIGS. FIG. 1 and FIG. 2 are diagrams for explaining a manufacturing process of a substrate, a movable electrode plate, and a mirror.
(Step 1) A substrate made of silicon is prepared as the substrate 1.
(Step 2) A polycrystalline silicon film is formed on the surface of the substrate 1 and patterned into the shape of the coupling portion 211, the flexure portion 21, and the movable electrode plate 2.
(Step 3) Both the front and back surfaces of the substrate 1 are covered with the silicon dioxide film 7, and a shape necessary for forming the counterbore 12 is patterned on the silicon dioxide film 7 on the back surface of the substrate 1.
[0014]
(Step 4) Etching is performed on the back surface of the substrate 1 to form counterbore holes 12.
(Step 5) Patterns necessary for forming two lens mounting recesses 13 and two cross-sectional V-shaped grooves 14 extending in parallel from these are patterned on the silicon dioxide film 7 on the surface of the substrate 1. . Here, the width of the pattern of the cross-sectional V-shaped groove 14 is changed in accordance with the depth of the cross-sectional V-shaped groove 14 to be formed. That is, the width of the pattern of the cross-sectional V-shaped groove 14 is increased in proportion to the depth of the cross-sectional V-shaped groove 14 to be formed.
[0015]
(Step 6) The surface of the substrate 1 is etched to form the lens mounting recess 13 and the cross-sectional V-shaped grooves 14 and 14 '.
(Step 7) The silicon dioxide film 7 remaining in the step 6 is removed.
(Step 8) A photosensitive synthetic resin E having a thickness of several tens of μm is applied to the entire surface of the substrate 1.
(Step 9) Of the photosensitive synthetic resin E, the mirrors 31, 32, 31 ′, and 32 ′ are exposed L from above only to form the mirror shape m.
[0016]
(Step 10) The portion of the photosensitive synthetic resin E that is developed and not exposed is removed.
(Step 11) The mirrors 31, 32, 31 ′, and 32 ′ having a height of several tens of μm are formed by coating a metal in a mirror shape.
Through the above (Step 1) to (Step 11), the substrate, the movable electrode plate, and the mirror as shown in FIG. 3 were formed.
(Step 12) Separately, a peripheral substrate is etched using a semiconductor substrate as a raw material substrate to form a central raised portion 81 and a collar portion 82 surrounding the central raised portion 81, as shown in FIG. 8 is manufactured and bonded and fixed to the lower surface of the substrate 1.
[0017]
FIG. 4 shows the 2 × 2 optical switch manufactured as described above. 4A is a view of the 2 × 2 optical switch as viewed from above, and FIG. 4B is a slightly enlarged cross-sectional view along the line bb ′ in FIG. FIG. 4 (c) is a diagram in which the cross section along line c-a 'in FIG. 4 (a) is slightly enlarged and viewed in the direction of the arrow, and FIG. 4 (d) is the line d in FIG. 4 (a). It is the figure which expanded the cross section along -d 'a little and looked at the direction of the arrow.
As described above with reference to FIG. 7 (e), the mirror base m is formed so that the surface on the opposite side of the optical fiber is not formed at a right angle with respect to the surface of the substrate 1, but is slightly inclined. Thus, the mirrors 31, 32, 31 ′ and 32 ′ on the upper surface of the finished movable electrode plate 2 are formed to be inclined at an acute angle or an obtuse angle as viewed from the surface of the movable electrode plate 2. Here, the mirrors 31 and 32 are referred to as a first mirror pair, and the mirrors 31 ′ and 32 ′ are referred to as a second mirror pair. Due to this inclination , the reflected light is incident on the incident side port with a difference in height, and the proper incidence on the respective lenses of the incident side optical fibers 5 and 5 ′ Therefore, in (Step 5), the width of the pattern of the cross-sectional V-shaped groove 14 is changed in accordance with the depth of the cross-sectional V-shaped groove 14 to be formed. The width of the pattern forming this is increased in proportion to the depth, and the depth of the V-shaped groove 14 to be formed is adjusted to be positioned and fixed between the incident side optical fiber and the output side optical fiber. A difference in height is formed.
[0018]
Specifically, when the surface of the mirror facing the optical fiber side is inclined at an acute angle when viewed from the surface of the movable electrode plate 2, the cross-sectional V-shaped groove 14 at the exit side port 1 has a standard depth. In order to form a V-shaped standard groove in the cross section, patterning is performed to a standard pattern width correspondingly. The cross-sectional V-shaped groove 14 in the port 2 forms a cross-sectional V-shaped deep groove slightly deeper than the standard depth, and correspondingly, the cross-sectional V-shaped groove 14 is patterned to have a slightly wider pattern width than the standard pattern width. The cross-sectional V-shaped groove 14 in the incident side port 3 forms a standard V-shaped cross-sectional standard groove, and is patterned to a standard pattern width correspondingly. The cross-sectional V-shaped groove 14 in the port 4 forms a cross-sectional V-shaped deep groove that is slightly shallower than the standard depth, and is correspondingly patterned to a narrow pattern width that is slightly smaller than the standard pattern width. By making the pattern width for forming the cross-sectional V-shaped groove 14 large, the depth of the cross-sectional V-shaped groove 14 to be formed increases in proportion to the pattern width.
[0019]
As described above, the depth of the cross-sectional V-shaped groove 14 at each port is port 2> port 1
Port 3> Port 4
Formed in a relationship. However, in the embodiment, the depth of the cross-sectional V-shaped groove 14 in the port 1 and the port 3 is set equal.
Thereby, the relationship of the height of the optical fiber positioned and fixed in the cross-sectional V-shaped groove 14 in each port is
Port 2 <port 1
Port 3 <Port 4
It becomes.
[0020]
Referring to FIG. 4, in a steady state where the movable electrode plate 2 is not attracted downward, the light emitted from the optical fiber 4 of the port 1 enters the mirror 31 through the microlens 91 and is reflected in the horizontal direction. From here, it enters the mirror 31 and reflects. Assuming that the mirrors 31 and 32 are formed to be slightly inclined toward the optical fiber 4 facing each other, the horizontally reflected light from the mirror 31 is reflected with a slightly downward component and enters the mirror 32. In addition, it has a slightly downward component, is reflected in the horizontal direction, and enters the optical fiber 5 of the port 2 through the micro lens 92. The light emitted from the optical fiber 4 of the port 1 is reflected horizontally in the mirrors 31 and 32 twice with the downward component, so that the light level when reaching the port 2 is the port 1 It is lower than the level when the light is emitted from. Taking this decrease into consideration in advance, the height of the optical fiber 5 of the port 2 is lowered with the height of the optical fiber 4 of the port 1 as a reference, and the optical fiber 4 and the optical fiber 5 are positioned and fixed. To set this height, the depth of the cross-sectional V-shaped groove 14 in the port 1 is set as a reference depth, and the depth of the cross-sectional V-shaped groove 14 in the port 2 is set deeper than the reference depth. Similarly, for the ports 3 and 4, the height of the optical fiber 4 ′ of the port 4 on the light emitting side is positioned and fixed higher than the height of the optical fiber 5 ′ of the port 3 on the light incident side. . That is, the depth of the cross-sectional V-shaped groove 14 of the port 4 is formed shallower than the standard, while the depth of the cross-sectional V-shaped groove 14 of the port 3 is formed to the standard depth.
[0021]
To summarize the above, when the surface of the mirror facing the optical fiber side is inclined at an acute angle when viewed from the surface of the movable electrode plate 2, it is compared with the depth of the cross-sectional V-shaped groove 14 of the exit side port. The cross section of the incident side port positioned and fixed to the incident side port is made deeper than the height of the optical fiber of the cross section V groove 14 positioned and fixed to the output side port. The height of the optical fiber in the V-shaped groove 14 is lowered.
Conversely, when the surface of the mirror facing the optical fiber side is inclined at an obtuse angle when viewed from the surface of the movable electrode plate 2, the incident side is compared with the depth of the cross-sectional V-shaped groove 14 of the exit side port. The depth of the cross-section V-shaped groove 14 of the port is formed to be shallow, and thereby the cross-section V-shaped that is positioned and fixed to the incident-side port as compared with the height of the optical fiber that is positioned and fixed to the cross-sectional V-shaped groove 14 of the output side port. The height of the optical fiber in the groove 14 is increased.
[0022]
Although the above description has been made with a 2 × 2 optical switch as an embodiment, the present invention is also applied to a 1 × 1 optical switch including an output side optical fiber 4, an incident side optical fiber 5, and mirrors 31 and 32 in FIG. The present invention can also be applied to a 1 × 2 optical switch having a second incident side optical fiber 5 ′.
[0023]
【The invention's effect】
As described above, according to the present invention, the incident position positioned and fixed in the cross-section V-shaped groove of the incident side port as compared with the height of the output side optical fiber positioned and fixed in the cross-section V-shaped groove of the output side port. By forming a height difference in the height of the side optical fiber, the arrival position of light arriving at the incident side port after entering and reflecting a component in the height direction of the mirror formed on the surface of the movable electrode plate By positioning and fixing the incident-side optical fiber, it is possible to make the incident on the incident-side optical fiber appropriate and reduce the insertion loss of light by the optical switch in the light transmission process.
[Brief description of the drawings]
FIG. 1 is a diagram illustrating an embodiment.
FIG. 2 is a continuation of FIG.
FIG. 3 is a diagram showing a substrate, a movable electrode plate, and a mirror that are integrally formed.
FIG. 4 is a diagram illustrating an example of a 2 × 2 optical switch.
FIG. 5 is a diagram showing a preceding example of a 2 × 2 optical switch.
FIG. 6 is a diagram illustrating a switching operation of a 2 × 2 optical switch.
FIG. 7 is a diagram illustrating a method of configuring a mirror.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 Substrate 2 Movable electrode plate 21 Flexure 31, 32 Mirror 4 Outgoing side optical fiber 5 Incident side optical fiber 8 Fixed electrode substrate

Claims (5)

Fixed electrode substrate, substrate, movable electrode plate attached to and coupled to the substrate via the flexure part, output side optical fiber arranged adjacent to the movable electrode plate along an adjacent straight line parallel to each other, and incident A mirror pair formed on the surface of the movable electrode plate so as to face the side optical fiber, the output side optical fiber and the input side optical fiber arranged along the straight lines parallel to each other. In an optical switch that controls the switching of light by electrostatically driving the movable electrode plate downwardly, by separately tilting the reflecting surface with respect to the linear direction along a straight line parallel to
Compared between the output side optical fiber and the incident side optical fiber that receives the reflected light from the mirror pair, the light level when it reaches the input side optical fiber is compared with the light level when it is emitted from the output side optical fiber. An optical switch characterized in that it is fixed to a substrate with a height difference corresponding to the reduced amount . The optical switch according to claim 1,
The second incident side optical fiber is fixed to the substrate at a position facing the mirror along the straight line on which the output side optical fibers are arranged without making a difference in height from the output side optical fiber. And an optical switch. A fixed electrode substrate, a substrate, a movable electrode plate attached to and coupled to the substrate via a flexure portion, a first emission-side optical fiber disposed adjacent to the movable electrode plate along straight lines parallel to each other, and A first mirror pair is formed on the surface of the movable electrode plate so as to face the first incident side optical fiber, and each of the first mirror pairs has a reflecting surface in a linear direction along the parallel lines. And a second exit side optical fiber and a second entrance side light having the same configuration as the first exit side optical fiber and the first entrance side optical fiber. A second output-side optical fiber, and a second output-side optical fiber, which are arranged along a straight line parallel to each other, and arranged on the same straight line as the first output-side optical fiber and the second input-side optical fiber. Movable opposite to the incident side optical fiber A second mirror pair formed on the surface of the electrode plate 2 is provided, and the second mirror pair is perpendicular to the substrate 1 with the reflecting surface inclined along the straight line parallel to each other with respect to the linear direction. An optical switch that is installed and electrostatically drives the movable electrode plate 2 downward to switch light;
The first and second incident side optical fibers and the first and second incident side optical fibers that receive the reflected light from the first and second mirror pairs are interposed between the first and second optical fibers. The light level when reaching the incident side optical fiber is fixed to the substrate with a height difference corresponding to the amount of light that has been reduced compared to the light level when emitted from the first and second output side optical fibers. An optical switch characterized by that. In the optical switch according to any one of claims 1 to 3,
A cross-sectional V-shaped groove is formed in each of the substrates along straight lines parallel to each other to position and fix the output side optical fiber and the input side optical fiber. Here, between the output side optical fiber and the input side optical fiber, The optical switch is characterized in that the height difference is formed by making a difference in the depth of the V-shaped cross section of both . The optical switch according to any one of claims 1 to 4,
An optical switch characterized in that the mirror is composed of a metal surface coated on the surface of a structure formed by exposing and developing a photosensitive synthetic resin.

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