JP2004118086A - Light beam switching adjustment device - Google Patents

Abstract

Provided is an optical beam switching adjustment device that can easily determine a positional relationship between a slit provided in an optical waveguide core and an insertion plate and an insertion position of the insertion plate in the slit.
A region including a slit of a core support substrate and a region including an insert plate of an insert plate driving mechanism support substrate are configured to transmit light having a wavelength used for microscopic observation. Was made to enter from one of these regions, and the transmitted light was emitted from the other region, and the insertion position of the insertion plate in the slit was observed with a microscope. Further, at least one uneven portion (depth detecting marker 116) is provided on the insertion plate, and the uneven portion is used as a reference for focusing in microscopic observation.
[Selection diagram] Fig. 1

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a light beam switching adjustment device, and more particularly, to a light beam switching adjustment device that facilitates determination of the positional relationship between a slit provided in an optical waveguide core and an insertion plate and the insertion position of the insertion plate in the slit. .
[0002]
[Prior art]
2. Description of the Related Art An optical communication system requires an optical switch for optical path conversion. Recently, a matrix optical switch for switching an optical path between a plurality of inputs and outputs has become particularly important. In order to realize such a matrix optical switch, a micromirror using MEMS technology (MEMS: Micro-Electro-Mechanical Systems) is arranged between optical paths, and this micromirror is put in and out of a slit provided in the optical path. Thus, there is known a light beam switching / adjusting device for changing the optical path of a light beam and adjusting the amount of transmission.
[0003]
FIG. 3 is a diagram for explaining a configuration example of a conventional light beam switching adjustment device using the MEMS technology. FIG. 3A is a plan view of the light beam switching adjustment device, and FIG. 3) is a cross-sectional view taken along line AA ′ of FIG.
[0004]
As shown in FIG. 3A, this optical beam switching adjustment device includes first to third optical waveguide cores 302a, 302b, and 302c on a core support substrate 301, and these optical waveguide cores are incident side optical fibers. A slit 303 is provided at the intersection of the optical waveguide cores so as to cross optical waveguides that intersect each other.
[0005]
Further, as shown in FIG. 3B, an insertion plate support substrate 304 is arranged in the upper surface region of the core support substrate 301 indicated by a dotted line in FIG. The insertion plate 305 is driven by an insertion plate driving mechanism 307 provided with electric wiring 306.
[0006]
The insertion plate 305 is disposed opposite to the upper portion of the slit 303, and the insertion plate 305 is driven up and down by the insertion plate driving mechanism 307 to perform insertion / removal into the slit 303. The switching operation by switching the optical path of the light beam entering the slit 303 from the fiber core 310 and the attenuation operation by adjusting the amount of transmitted light are enabled.
[0007]
That is, in a state where the insertion plate 305 is inserted into the slit 303, the light beam that has entered the slit 303 from the first optical waveguide core 302a is reflected by the insertion plate 305 and the end face of the second optical waveguide core 302b. On the other hand, when the insertion plate 305 is pulled out of the slit 303, the light beam incident on the slit 303 from the first optical waveguide 302a is coupled to the end face of the third optical waveguide core 302c as it is. The optical path of the light beam is switched to realize a switching operation.
[0008]
Also, if the insertion position (insertion depth) of the insertion plate 305 in the slit 303 is adjusted, a part of the light beam that enters the slit 303 from the first optical waveguide core 302a is blocked according to the insertion position. Then, the remaining light beam component is transmitted and coupled to the end face of the third optical waveguide core 302c, thereby realizing the attenuation operation of the transmitted light intensity.
[0009]
In order to drive the insertion plate 305, for example, the insertion plate driving mechanism 306 which is warped in advance by stress-induced curling may be a cantilever having one end fixed to the insertion plate support substrate 304 and the other end being a free end. And a method of supplying a current to the cantilever to generate an electrostatic force between the cantilever and the core supporting substrate 301 (for example, see Patent Document 1).
[0010]
By the way, in such a light beam adjusting device, the relative positional relationship between the slit formed in the optical waveguide core and the insertion plate is determined so that the reflection loss is minimized when the insertion plate functions as a reflection plate. There is a need. Further, in order to reduce the loss of the reflected light, it is preferable to adjust the position of the insertion plate with respect to the slit with an accuracy within 1 μm. Further, when adjusting the attenuation amount of the light beam, it is a condition that the insertion plate is smoothly driven by the insertion plate driving mechanism.
[0011]
In order to observe a highly accurate alignment state between the insertion plate and the slit in such a light beam adjustment device, it is necessary to accurately monitor the relative position and the insertion depth of the insertion plate in the slit from outside. is important.
[0012]
[Patent Document 1]
US Pat. No. 6,195,478
[Problems to be solved by the invention]
In order to monitor the relative positional relationship between the insertion plate and the slit after bonding the core support substrate and the insertion plate support substrate, microscope observation by an optical method is used, and in the case of an apparatus configured using a silicon substrate, In general, an infrared microscope is used, and when a glass substrate is used, observation is performed using a general optical microscope having a visible light source.
[0014]
However, in addition to the insertion plate driving mechanism being attached to the insertion plate supporting substrate, wiring is also provided for the operation of the insertion plate driving mechanism. There is a problem that observing relative position between the slit and the slit is greatly hindered.
[0015]
Further, depending on the width of the slit to be observed and the size of the insertion plate, the observation magnification at the time of microscopic observation becomes large, the depth of field becomes shallow, and the insertion position of the insertion plate in the slit is determined. There is also a problem that it becomes difficult.
[0016]
The present invention has been made in view of such a problem, and an object of the present invention is to easily determine a positional relationship between a slit provided in an optical waveguide core and an insertion plate and an insertion position of the insertion plate in the slit. Another object of the present invention is to provide a light beam switching adjustment device.
[0017]
[Means for Solving the Problems]
In order to achieve the above object, according to the present invention, an optical path of a light beam propagating through an optical waveguide is provided by inserting and removing an insertion plate into a slit provided in the optical waveguide. An optical beam switching and adjusting device for switching or adjusting the amount of transmitted light beam, wherein the optical waveguide and the slit are provided on a first substrate, and the insertion plate is provided on a second substrate. The first and second substrates are arranged so that the insertion plate can be inserted into and removed from the slits, and the first and second substrates include the slits of the first substrate. The first region and the second region of the second substrate including the insertion plate are configured to transmit light of a predetermined wavelength, and the light of the predetermined wavelength is transmitted to the first region or Incident from one of the second regions By emitting excessive light from one of the second region or the first region, characterized in that allowed the microscopic observation of the insertion position of the insertion plate within the slit.
[0018]
According to a second aspect of the present invention, there is provided a method for switching an optical path of a light beam propagating in the optical waveguide or adjusting a transmitted light amount of the light beam by inserting and removing an insertion plate into a slit provided in the optical waveguide. An optical beam switching adjustment device, wherein the optical waveguide and the slit are provided on a first substrate, and the insertion plate is provided while being held by insertion plate driving means provided on a second substrate. Wherein the first and second substrates are arranged such that the insertion plate can be inserted into and removed from the slit, and the first region including the slit of the first substrate or the insertion of the second substrate. One of the second regions including the plate is configured to transmit light of a predetermined wavelength, and the light of the predetermined wavelength is incident from one of the first region or the second region. And the reflected light in the first area. Or said is emitted from the second region, characterized by being capable Microscopy of the insertion position of the insertion plate within the slit.
[0019]
Further, according to a third aspect of the present invention, in the light beam switching adjustment device according to the first or second aspect, the insertion plate includes at least one concave and convex portion, and the concave and convex portion is used as a focus reference for the microscopic observation. This makes it possible to observe the insertion depth of the insertion plate in the slit.
[0020]
BEST MODE FOR CARRYING OUT THE INVENTION
An embodiment of the present invention will be described below with reference to the drawings.
[0021]
FIG. 1 is a view for explaining a configuration example of a light beam switching adjustment device of the present invention. FIG. 1A is a plan view of this device, and FIG. It is sectional drawing in AA '.
[0022]
As shown in FIG. 1A, this optical beam switching adjustment device includes first and second optical waveguide cores 101 (101a and 101b) on a core support substrate 112, and the first optical waveguide core 101a The end is connected to the incident side optical fiber 105 or the transmission side optical fiber 106, and one end of the second optical waveguide core 101 b is connected to the reflection side optical fiber 107. A slit 102 is provided at the intersection of the optical waveguide cores so as to cross the optical waveguide. In FIG. 1A, the insertion plate driving mechanism accommodating portion 113 and the insertion plate driving mechanism support substrate 114 are omitted.
[0023]
Further, as shown in FIG. 1B, an insertion plate driving mechanism support substrate 114 is disposed in an upper surface region of the core supporting substrate 112 via an insertion plate driving mechanism accommodating portion 113, and the insertion plates 103 (103a and 103b) are provided. Are supported by the insertion plate driving mechanism 111 supported by the insertion plate driving mechanism support substrate 114. The insertion plate driving mechanism support substrate 114 is provided with an insertion plate driving wiring 110 connected to a wiring terminal 109 provided on a side surface of the core support substrate 112, and is disposed to face the upper portion of the slit 102. The insertion plate 103 is driven up and down by an insertion plate driving mechanism 111 operated by an electromagnetic force or an electrostatic force, whereby the insertion and removal in the slit 102 is performed, and the optical path of the light beam incident from the optical fiber core unit 108 is changed. Switching operation by switching and attenuation operation by adjusting the amount of transmitted light are enabled.
[0024]
That is, as shown in FIG. 1A, for example, when the insertion plate 103b is pulled out of the slit 102b, the light enters the slit 102b from the first optical waveguide core 101a coupled to the incident side optical fiber 105. The incident light beam 104a is directly coupled to the end face of the opposing optical waveguide core 101a to form a transmitted light beam 104c. On the other hand, when the insertion plate 103a is inserted into the slit 102a, the incident light beam 104a is transmitted by the insertion plate 103a. The light is reflected and becomes a reflected light beam 104b, which is coupled to the end face of the optical waveguide core 101b to switch the light path of the light beam, thereby realizing a switching operation. The insertion position (insertion depth) of the insertion plate 103 in the slit 102 can be adjusted to realize an operation of attenuating the transmitted light intensity.
[0025]
Normally, in the light beam switching device, the wiring for driving the insertion plate is a metal wiring, and this metal wiring hinders the microscope observation of the insertion position (insertion depth) of the insertion plate in the slit. In particular, when the metal wiring is arranged near the slit and the insertion plate, observation becomes extremely difficult. For this reason, in the light beam switching device of the present invention, the insertion plate driving wiring 110 is arranged not around the insertion plate 103 but around the insertion plate 103 so that the slit 102 and the insertion plate 103 are parallel to the surface of the core holding substrate 112. It is devised to make it easy to observe the in-plane positional relationship in the plane.
[0026]
In other words, as shown in FIG. 1A, the wiring 110 for driving the insertion plate is wired so as to avoid the positions of the slit 102 and the insertion plate 103, and the normal direction of the surface of the core support substrate 112, which is the normal observation direction. It is designed so as not to hinder the observation of the in-plane positional relationship between the slit 102 and the insertion plate 103. Further, in this light beam switching adjustment device, in order to enable observation of the surface of the core support substrate 112 from the normal direction, the region 115 including the slit 102 and the insertion plate 103 shown in FIG. The region 115 is formed of a material that transmits light used for microscopic observation, and the shape of the region 115 is a shape that does not block observation light.
[0027]
The configuration of the device shown in FIG. 1 is a configuration example in the case where observation light is transmitted through the core support substrate 112 and the insertion plate driving mechanism support substrate 114 to perform observation, and light is incident from the core support substrate 112 side. In the case of an apparatus for observing the position from the reflected image, a material and a shape in which a region including the slit 102 of the core supporting substrate 112 is transparent to observation light may be used. When light is incident from the side of the insertion plate driving mechanism support substrate 114 and the reflected light is observed, the region of the insertion plate driving mechanism support substrate 114 near the insertion plate 103 may be configured to be transparent to the observation light. Just fine.
[0028]
The outline of the manufacturing process of the light beam switching adjustment device of the present invention is as follows.
[0029]
In the light beam switching adjustment device, it is necessary to minimize the light loss in the slit of the transmitted light beam and the reflected light beam with respect to the incident light beam. In order to reduce the light loss in the slit to, for example, about 0.5 dB or less, it is preferable that the slit width is set to 10 μm or less. When forming the waveguide core and the slit, a so-called "PLC (planar light wave circuit)" technique of etching quartz after depositing quartz on a silicon substrate is employed. The core support substrate of the light beam switching adjustment device of the present invention may be a glass substrate or the like in addition to the silicon substrate.
[0030]
When the light beam switching adjustment device of the present invention is used only as a variable attenuator that changes the transmitted light beam intensity by controlling the position of the insertion plate in the slit, it is necessary to provide a switching operation function among the above-described functions. There is no. In this case, it is not necessary to form the optical waveguide cores that cross each other as shown in FIG. 1, and it is not necessary to use the PLC technology for forming the optical waveguide cores. In such a case, a glass substrate capable of specifying the position of an optical fiber by providing a V-groove or the like is used, and a slit is formed in the optical fiber bonded and fixed to the glass substrate. The substrate may be a core supporting substrate.
[0031]
On the other hand, the insertion plate is formed on a silicon substrate using MEMS technology, and this silicon substrate is used as an insertion plate drive mechanism support substrate, and the in-plane positional relationship between the slit and the insertion plate is optimized by a previously provided alignment mark or the like. By bonding, a light beam switching device is completed. The present invention, which can be monitored from the outside, is also effective when finely adjusting the alignment between the insertion plate and the slit before the bonding is completed.
[0032]
In order to confirm the effect of the configuration adopted in the above-described light beam switching device of the present invention, each of the optical waveguide core and the insertion plate is formed on a core support substrate and an insertion plate driving mechanism support substrate which are silicon substrates, and further, A light beam switching adjustment device was manufactured by forming aluminum insertion plate driving wires on the insertion plate driving mechanism support substrate in a pattern that avoids wiring near the insertion plate and the slit. As a result of transmitting infrared light from the core supporting substrate side of the light beam switching adjustment device and observing the transmitted light with an infrared microscope from the insertion plate driving mechanism supporting substrate side, the infrared light is not shielded by the insertion plate driving wiring and the like. The in-plane positional relationship between the insertion plate and the slit was clearly observed.
[0033]
Also, when the reflected image is observed by irradiating infrared rays from the insertion plate drive mechanism support substrate side and when the reflected image is observed by irradiating infrared rays from the core support substrate side from the core support substrate side, The in-plane positional relationship between the slit and the slit was clearly observed.
[0034]
Furthermore, in the variable attenuator in which the glass substrate is used as the core supporting substrate and the optical waveguide core of the optical fiber core is formed thereon, the in-plane positional relationship between the insertion plate and the slit is clearly observed from the core supporting substrate side. Was.
[0035]
The position observation described so far relates to the relative position of the insertion plate and the slit in a plane parallel to the surface of the core support substrate. In the case of such a plane observation, the focus of the microscope is inserted. Even if it can be adjusted to the plate, the depth of field is shallow at a high magnification of the microscope, so the position of the insertion plate in the slit in the depth direction is usually unknown. The position in the depth direction of the plate is difficult to understand. In order to simultaneously obtain the positional information in the depth direction in the slit of the insertion plate in addition to the positional relationship information in the plane, the depth detection marker ( It is effective to provide a mark), and the depth position of the insertion plate can be observed by focusing the microscope on this marker.
[0036]
FIG. 2 is a view for explaining a state in the vicinity of the slit 102 and the insertion plate 103 of the light beam switching device of the present invention having a configuration in which a projection-like depth detection marker 116 is provided at an appropriate position on the insertion plate 103. The insertion plate 103 shown in this figure is provided with a total of six depth detecting markers 116, three on each of the left and right sides. Although the depth detection marker 116 is provided on the insertion plate 103 in this drawing, a configuration in which markers are formed on both the insertion plate 103 and the optical waveguide core 101 may be employed. When this configuration is adopted, not only is the relationship between the insertion plate 103 and the slit 102 in the depth direction easier to observe, but also the observation is made so that the extension direction of the insertion plate 103 matches the direction of the position observation. By setting the conditions, the degree of inclination of the insertion plate 103 in the slit 102 can be obtained from the degree of overlap between the markers. Further, the shape of the marker is not limited to the protrusion, but may be any uneven portion such as a dent (an inflection portion), and at least one such marker may be provided on the insertion plate 103.
[0037]
Further, when a projection of a depth detection marker is attached to the tip end of the insertion plate 103 as, for example, 116a, this observes the positional relationship between the slit 102 and the insertion plate 103 from the core support substrate 112 side after bonding. This is convenient for fine adjustment of adhesion.
[0038]
In order to confirm the effect of providing such a marker, the state of insertion of the insertion plate 103 into the slit 102 was observed using a light beam switching adjustment device having the configuration shown in FIG. As a result, when the position of the protrusion was read on the depth scale of the microscope with reference to the depth of the core 101, the position of the insertion plate 103 could be detected within 3 μm. Further, when the projections were observed to overlap each other, it was also confirmed that the insertion plate hardly tilted in the observation direction. Furthermore, when the projections were not observed overlapping with each other, it was possible to calculate the inclination of the insertion plate from the displacement of each projection in the horizontal direction and the distance between the projections when the insertion plate was manufactured.
[0039]
【The invention's effect】
As described above, in the light beam switching adjustment device of the present invention, the region including the slit of the core supporting substrate and the region including the insertion plate of the insertion plate driving mechanism supporting substrate emit light having a wavelength used for microscopic observation. It is configured to transmit light, and observation light is made incident from one of these areas, and the transmitted light is emitted from the other area to enable microscopic observation of the insertion position of the insertion plate in the slit.
[0040]
Further, in the light beam switching adjustment device of the present invention, one of the region including the slit of the core supporting substrate and the region including the insertion plate of the insertion plate driving mechanism supporting substrate transmits light of a wavelength used for microscopic observation. The observation light is made to enter from the transmission region, and the reflected light enables the microscope observation of the insertion position of the insertion plate in the slit.
[0041]
Further, in the light beam switching adjustment device of the present invention, at least one uneven portion is provided on the insertion plate, and the uneven portion is used as a reference for focusing for microscopic observation.
[0042]
Accordingly, it is possible to provide a light beam switching adjustment device that can easily determine the positional relationship between the slit provided in the optical waveguide core and the insertion plate and the insertion position of the insertion plate in the slit.
[Brief description of the drawings]
FIGS. 1A and 1B are diagrams illustrating a configuration example of a light beam switching adjustment device according to the present invention, wherein FIG. 1A is a plan view of the device, and FIG. 1B is a cross-sectional view taken along line AA ′ of FIG. FIG.
FIG. 2 is a view for explaining a state near a slit and an insertion plate of the light beam switching adjustment device of the present invention in which a depth detection marker is provided on the insertion plate.
3A and 3B are diagrams illustrating a configuration example of a conventional light beam switching adjustment device using MEMS technology, wherein FIG. 3A is a plan view of the light beam switching adjustment device, and FIG. FIG. 4 is a sectional view taken along line AA ′ of FIG.
[Explanation of symbols]
101, 302a, 302b, 302c Optical waveguide core 101a First optical waveguide core 101b Second optical waveguide core 102, 303 Slits 103, 103a, 103b, 305 Insertion plate 104a Incident light beam 104c Transmitted light beam 104b Reflected light beam 105 , 308 Incident-side optical fiber 106, 309 Transmitting-side optical fiber 107 Reflecting-side optical fiber 108, 310 Optical fiber core unit 109 Wiring terminal 110 Insert plate driving wiring 111, 307 Insert plate driving mechanism 112, 301 Core support substrate 113 Insert plate Drive mechanism accommodating portion 114 Insert plate drive mechanism support substrate 115 Areas 116, 116a Depth detection marker 304 Insert plate support substrate 306 Electrical wiring

Claims (3)

An optical beam switching adjustment device for adjusting an optical path switching of a light beam propagating in the optical waveguide or adjusting a transmitted light amount of the light beam by inserting and removing an insertion plate in a slit provided in the optical waveguide,
The optical waveguide and the slit are provided on a first substrate,
The insertion plate is provided while being held by an insertion plate driving means provided on the second substrate,
The first and second substrates are arranged such that the insertion plate can be inserted into and removed from the slit.
A first region including the slit of the first substrate and a second region including the insertion plate of the second substrate are configured to transmit light of a predetermined wavelength,
The light having the predetermined wavelength is incident from one of the first region and the second region, and the transmitted light is emitted from one of the second region and the first region, and the light is transmitted through the slit. A light beam switching and adjusting device, wherein a microscope observation of the insertion position of the insertion plate is enabled. An optical beam switching adjustment device for adjusting an optical path switching of a light beam propagating in the optical waveguide or adjusting a transmitted light amount of the light beam by inserting and removing an insertion plate in a slit provided in the optical waveguide,
The optical waveguide and the slit are provided on a first substrate,
The insertion plate is provided while being held by an insertion plate driving means provided on the second substrate,
The first and second substrates are arranged such that the insertion plate can be inserted into and removed from the slit.
Either a first region including the slit of the first substrate or a second region including the insertion plate of the second substrate is configured to transmit light of a predetermined wavelength,
The light of the predetermined wavelength is made incident from one of the first region and the second region, and the reflected light is emitted from the first region or the second region, and A light beam switching adjustment device, wherein the insertion position of the insertion plate can be observed with a microscope. The insertion plate includes at least one uneven portion,
The light beam switching adjustment device according to claim 1 or 2, wherein an observation of the insertion depth of the insertion plate in the slit is made possible by using the concave and convex portion as a focus reference for the microscope observation. .

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