JP3721420B2

JP3721420B2 - Light switch

Info

Publication number: JP3721420B2
Application number: JP5742799A
Authority: JP
Inventors: 嘉睦加藤
Original assignee: Japan Aviation Electronics Industry Ltd
Current assignee: Japan Aviation Electronics Industry Ltd
Priority date: 1999-03-04
Filing date: 1999-03-04
Publication date: 2005-11-30
Anticipated expiration: 2019-03-04
Also published as: JP2000258702A

Description

【０００１】
【発明の属する技術分野】
この発明は可動電極板にミラーを立て、可動電極板と固定電極との間に静電引力を作用させたり、除去させたりしてミラーを変位させ、ミラーに向かう光束を通過又は反射させる光スイッチに関する。
【０００２】
【従来の技術】
図７に提案されている光スイッチを示す。方形シリコン基板１１に方形凹部１２が形成され、方形凹部１２の中央部と対向して方形可動電極板１３が配され、可動電極板１３の対向辺の中点がそれぞれフレクチュア部１４，１５を介して基板１１上に連結され、フレクチュア部１４，１５により、可動電極板１３は、基板１１の表面に対して垂直方向に変位自在に基板１１に支持されている。可動電極板１３の基板１１と反対側の面上にミラー１６が立てられている。
【０００３】
可動電極板１３、フレクチュア部１４，１５はシリコン基板１１と一体に形成され、シリコン基板１１、可動電極板１３にそれぞれ不純物が混入されて導電性が与えられている。よって基板１１の可動電極板１３と対向する部分は固定電極として作用させることができる。入射側光ファイバ又は光導波路１７よりの光束１８が基板１１の表面と平行にミラー１６に斜めに入射され、その反射光が出射側光ファイバ又は光導波路１９に入射される。この状態で基板１１と可動電極板１３との間に電圧が印加されると、基板１１と可動電極板１３との間に静電引力が作用し、可動電極板１３が基板１１側に変位し、入射側光ファイバ又は光導波路１７よりの光束１８はミラー１６に入射することなく、ミラー１６上を通過し、他方の出射側光ファイバ又は光導波路２１に入射する。
【０００４】
このように基板１１と可動電極板１３との間に電圧を印加するかしないかにより、入射側光ファイバ又は光導波路１７よりの光束１８を出射側光ファイバ又は光導波路１９と出射側光ファイバ又は光導波路２１との一方に切替え入射させることができる。
【０００５】
【発明が解決しようとする課題】
図７に示した提案されている光スイッチにおいては、比較的大きな駆動電圧を必要とする。駆動電圧を低減するにはフレクチュア部１４，１５を含む支持部材の基板１１と可動電極板１３との間の長さを長くして柔らかにするか、可動電極板１３の面積を大きくする必要がある。このようにフレクチュア部を含む支持部材を長くしたり、可動電極板１３の面積を大きくすると、光スイッチの大きさが大型化してしまう。この大型化は、Ｎ×Ｍマトリックス状に個々の光スイッチを配置した大規模な光スイッチ装置（マトリックス光スイッチ）では、顕著な大型化を招くことになる。
【０００６】
この発明の目的は小型に構成でき、しかも低電圧駆動が可能な、マトリックス光スイッチに適する光スイッチを提供することにある。
【０００７】
【課題を解決するための手段】
この発明によれば、可動電極板を基板上に支持する支持体は可動電極板とほぼ平行な面内で、折り返しビーム状に形成され、支持体が占める領域と可動電極板が占める領域とが全体として方形領域を構成している。
【０００８】
【発明の実施の形態】
図１にこの発明の実施例を示す。方形基板３１と間隔をおいてこれと平行に可動電極板３２が配され、可動電極板３２は弾性を有する支持体３３〜３６により基板３１に支持されている。各支持体３３〜３６はそれぞれ、可動電極板３２がなす平面とほぼ同一平面上で折り返しビーム状に形成されている。支持体３３〜３６がそれぞれ占める領域３７〜４０と、可動電極板３２が占める領域とは全体としてほぼ方形、この例では正方形領域を構成する。
【０００９】
つまりこの実施例では、正方形状の可動電極板３２の各辺の中央部に長方形の切除部４１〜４４が形成され、その切除部４１〜４４にそれぞれ支持体３３〜３６が配され、各支持体３３〜３６はそれぞれその各外端は、可動電極板３２の各辺の中点と対応して、基板３１上に立てられた固定部４５〜４８と連結され、内端は切除部４１〜４４の内端の中点にて可動電極板３２に連結され、これら外端と内端間においてそれぞれ切除部４１〜４４の幅方向にほぼ一杯に延長して折り返すことが繰り返されて繰り返しビーム状支持体３３〜３６が構成されている。
【００１０】
つまり可動電極板３２の中央正方形部３２ａの各辺の中点にそれぞれ支持体３３〜３６の内端が連結され、それぞれ折り返されながら互いに外側へ延長されて、それぞれ固定部４５〜４８に連結される。これら支持体３３〜３６の各両側に可動電極板３２の周辺正方形部３２ｂ，３２ｃ，３２ｄ，３２ｅが中央正方形部３２ａの各頂角部分と一部、一つの頂角部分を共通として配されている。支持体３３〜３６の各折り返し幅Ｌ２は切除部４１〜４４の各幅Ｗ１よりわずか小とされている。
【００１１】
支持体３３〜３６は基板３１上の固定部４５〜４８の上端と連結され、これにより可動電極板３２は基板３１と間隔Ｄ１を保って保持され、また支持体３３〜３６の折り返しビーム状構造により、支持体３３〜３６は弾性を有し、可動電極板３２は基板３１に対し垂直に変位可能とされている。基板３１、可動電極板３２、支持体３３〜３６、固定部４５〜４８は一体物として構成することができる。
【００１２】
この構造は例えば図２に示すように作ることができる。図２Ａに示すようにシリコン基板３１ａ上にＳｉＯ₂の保護膜５１を形成し、フォトリゾグラフィにより、固定部４３〜４８が設けられる位置の保護膜５１を図２Ｂに示すように除去して小穴５２を形成する。図２Ｃに示すように、可動電極板３２となる多結晶シリコン層５３を全体の上に形成し、多結晶シリコン層５３に対し、図２Ｄに示すようにフォトリゾグラフィによりパターンニングして可動電極板３２、支持体３３〜３６、固定部４５〜４８を形成する。
【００１３】
次に図２Ｅに示すようにＳｉＯ₂の保護膜５４，５５を可動電極板３２を含む全面と、基板３１ａの底面とにそれぞれ形成し、図２Ｆに示すようにその底面の保護膜５５を周辺部を残して除去し、これをマスクとして基板３１ａをＫＯＨ溶液でエッチングし、図２Ｇに示すように可動電極板３２と対応する部分に大きな穴５６を開け、基板３１ａは枠のみ残す。その後、化学的エッチングによりＳｉＯ₂の保護膜５１，５４，５５を除去し、図２Ｈに示すように、枠状基板３１ａ上に可動電極板３２が支持された構造体を得る。図２Ｉに示すように、この枠状基板３１ａの枠内を、可動電極板３２と反対側からシリコン基板３１ｂで塞ぎ、基板３１ａ，３１ｂを接合させる。基板３１ａと３１ｂとにより図１中の基板３１が構成される。
【００１４】
可動電極板３２上に図１に示すようにミラー４９が立てられる。ミラー４９の鏡面は、例えば支持体３３，３４を結ぶ方向と４５度をなすようにされる。可動電極板３２が静電引力により基板３１側に変位することができるようにされる。つまり可動電極板３２は導電性体で構成され、例えばシリコンに適当に不純物が混入されて導電性が与えられ、また基板３１もシリコンに不純物が混入されて導電性体とされ、基板３１自体を固定電極とされる。基板３１上に導電膜を形成して固定電極としてもよい。
【００１５】
ミラー４９は可動電極板３２と一体に形成してもよいし、別体のミラー４９を可動電極板３２に固着してもよい。可動電極板３２、支持体３３〜３６の厚みは例えば２〜５μｍ程度とされる。
この光スイッチも、図７に示したものと同様に、図１において左側に配された入射側光ファイバ又は光導波路１７からの光束１８はミラー４９に入射し、これにて反射され、出射側光ファイバ又は光導波路１９に入射する。可動電極板３２と基板３１の間に電圧が印加され、これら間に静電引力を作用させると、可動電極板３２が基板３１側に変位して、入射側光ファイバ又は光導波路１７よりの光束はミラー４９上を通過して反対側の出射側光ファイバ又は光導波路２１に入射する。よって可動電極板３２と基板３１との間に電圧を印加するかしないかにより、光ファイバ又は光導波路１７からの光束を光ファイバ又は光導波路１９と光ファイバ又は光導波路２１とに切替え入射させることができる。
【００１６】
この光スイッチの寸法としては例えば可動電極板３２の１辺の長さＬ４を１０００μｍ、支持体３３〜３６の各長さＬ１を３００μｍ、その折り返し幅Ｌ２を２００μｍ、ビーム幅Ｗ２を１０μｍ、固定部４５〜４８をそれぞれ角柱状とし、その断面を５０μｍ□とし、中央方形部３２ａと各周辺方形部３２ｂ〜３２ｅとの各共通部の長さＬ３を３０μｍとする。
【００１７】
このように方形電極板３２の一部を切除して、その切除部に支持体３３〜３６を配しているため、方形電極板３２の面積を大きくとることができ、支持体３３〜３６は折り返しビーム状とされているため、その長さＬ１に対し、ビームの長さが長くなり、柔らかいものとすることができる。図７の考えからすると可動電極板は中央正方形部３２ａのみであったが、この実施例では支持体３３〜３６の部分の両側に周辺正方形部３２ｂ〜３２ｅを配し、中央正方形部３２ａと連結し、可動電極板３２の面積が著しく大きくなったと云える。前記数値例では中央正方形部３２ａの３００×３００μｍ²に対し、４つの周辺正方形部３２ｂ〜３２ｅの４×３８０×３８０μｍ²分、面積が増加したと云える。あるいは逆に可動電極板３２に切除部を設け、切除部内に支持体３３〜３６を配置し、全体の大きさを著しく小さくしたと云える。
【００１８】
図１の実施例では可動電極板３２を、その中心に対し、９０度角間隔で支持体３３〜３６により４点支持したが、図３Ａに示すように２つの支持体３３，３４により１８０度角間隔で２点支持としてもよい。この場合の数値例を示す。可動電極板３２は１辺が１０００μｍの正方形（ただし二つの長方形切除部４１，４２がある）、支持体３３，３４の各長さＬ１を３００μｍ、その折り返し幅Ｌ２を２００μｍ、ビーム幅Ｗ２を１０μｍ、固定部４５，４６の断面を５０μｍ□、切除部４１と４２の内端間の距離Ｌ３を３００μｍ、切除部４１，４２の幅Ｗ１を２４０μｍとする。なお図３Ａに示す実施例では基板３１を、可動電極板３２の正方形形状とほぼ同一とした場合である。つまりこの光スイッチの水平面内の大きさは、可動電極板３２の大きさと一致し、光スイッチの外形は前記数値例では１０００μｍ４方となる。
【００１９】
図３Ｂに示すように可動電極板３２を１点支持とさせることもできる。つまり、可動電極板３２の一辺に沿って二つの支持体３３，３４が配され、支持体３３，３４の離れた端が固定部４５，４６を介して基板３１に連結され、接近した端が互いに連結され、その連結点が連結部６１を介して可動電極板３２の隣接辺の中点に連結される。つまりこの連結部６１との連結点で可動電極板３２は支持体３３，３４により片持支持される。正方形可動電極板３２の一辺に沿ってその一部が切除された切除部６２が形成され、その切除部６２に支持体３３，３４が配されていると云える。
【００２０】
この場合の数値例は、可動電極板３２の長い辺Ｌ４を１０００μｍ、短い辺Ｌ５を７８０μｍ、支持体３３，３４の各長さＬ１を４５０μｍ、折り返し幅Ｌ２を２００μｍ、ビーム幅Ｗ１を１０μｍ、連結部６１の長さＬ３を１１５μｍ、幅Ｗ２を１０μｍ、固定部４５，４６の断面を５０μｍ□とする。光スイッチの外形は１０００μｍ４方となる。
【００２１】
１点支持であるが図４Ａに示すように構成することもできる。即ち、長方形可動電極板３２の二つの長辺にそれぞれ沿った支持体３３，３４が配され、支持体３３，３４の同一側の一端が固定部４５，４６をそれぞれ介して基板３１に連結され、支持体３３，３４の他端が連結ビーム６２の両端に連結され、連結ビーム６２の中点が可動電極板３２の一つの短辺の中点に連結される。つまり支持体３３，３４と連結ビーム６２により、可動電極板３２がその一つの短辺を残して囲まれている。正方形の可動電極板３２の両側辺部を切除し、その切除部に支持体３３，３４が配されているとも云える。このようにすると支持体３３，３４の長さを長くすることができる。
【００２２】
この場合の数値例を示す。支持体３３，３４の各長さＬ１を９４０μｍ、折り返し幅Ｌ２を２００μｍ、ビーム幅Ｗ１を１０μｍ、連結ビーム６２の長さＬ３を８１０μｍ、幅Ｗ２を１０μｍ、固定部４５，４６の断面を５０μｍ□、可動電極板３２の長辺Ｌ４を９７０μｍ、短辺Ｌ５を５６０μｍとする。光スイッチの各形が１０００μｍ４方となる。
【００２３】
図４Ｂに示すように、図４Ａ中の連結ビーム６２を省略して支持体３３，３４の各一端を連結部６３，６４で可動電極板３２の短辺の両端に連結してもよい。この場合の数値例は、支持体３３，３４の長さＬ１が９４０μｍ、折り返し幅Ｌ２が２００μｍ、ビーム幅Ｗ１が１０μｍ、連結部６３，６４の長さＬ３が１２５μｍ、幅Ｗ２が１０μｍ、固定部４５，４６の端面が５０μｍ□、可動電極板３２の長辺Ｌ４が１０００μｍ、短辺Ｌ５が５６０μｍ、光スイッチの外形が１０００μｍ４方となる。
【００２４】
図５Ａに示すように、図３Ｂに対し、支持体３３，３４と可動電極板３２と反対側に同様に支持体３５，３６を設け、その支持体３５，３６を連結し、その連結点を可動電極板３２に連結して、可動電極板３２を２点支持とすることもできる。
図５Ｂに示すように正方形スイッチ外形６５に内接して９０度回転された正方形可動電極板３２を配し、可動電極板３２の各辺の中点に、支持体３３〜３６の各一端を連結し、支持体３３〜３６の各他端を、光スイッチ外形６５の各コーナ部で基板３１に立てた固定部４５〜４８に連結する。各支持体３３〜３６はその折り返しビームの幅を、可動電極板３２側で大きく、固定部側で小さくなるようにして、可動電極板３２と光スイッチ外形６５との空き領域を有効に使用する。この場合も、可動電極板３２は光スイッチ外形６５と同様であった所を各コーナ部を切除し、その切除部を埋めるように支持体３３〜３６を配したと云うことができる。
【００２５】
図６に示すように、可動電極板３２の外形を、光スイッチ外形６５とほぼ一致させ、可動電極板３２の各コーナ部より中心に向って長方形の切除部４１〜４４を設け、これら切除部４１〜４４に支持体３３〜３６を配し、支持体３３〜３６の各内端を可動電極板３２に連結し、各外端を固定部４５〜４８を介して基板３１に連結する。
【００２６】
上述では支持体として折り返しビーム状のものを用いたが、弾性をもつものであればよく、例えば図７に示した方形状部を設けたフレクチュア部でもよい。
【００２７】
【発明の効果】
この発明によれば可動電極板と支持体が占める領域との全体が占める領域が方形状となっているため、マトリックス光スイッチを構成した場合スペースを無駄なく利用できる。
可動電極板の切除部に支持体が配されているため、小型に構成でき、かつ可動電極板の面積を大きくすることができ、つまり光スイッチ外形面積が無駄なく有効に利用され、低電圧駆動が可能である。
【図面の簡単な説明】
【図１】Ａはこの発明の実施例を示す平面図、Ｂは図１ＡのＡ−Ａ線断面図。
【図２】図１の実施例の製造工程を示す断面図。
【図３】この発明の他の実施例を示す平面図。
【図４】この発明の更に他の実施例を示す平面図。
【図５】この発明の更に他の実施例を示す平面図。
【図６】この発明の更に他の実施例を示す平面図。
【図７】Ａに提案されている光スイッチの平面図、ＢはＡのＡ−Ａ線断面図である。[0001]
BACKGROUND OF THE INVENTION
The present invention relates to an optical switch in which a mirror is set up on a movable electrode plate, and an electrostatic attractive force is applied or removed between the movable electrode plate and a fixed electrode to displace the mirror and pass or reflect a light beam directed to the mirror. About.
[0002]
[Prior art]
FIG. 7 shows a proposed optical switch. A rectangular recess 12 is formed in the rectangular silicon substrate 11, a rectangular movable electrode plate 13 is arranged opposite to the central portion of the rectangular recess 12, and the midpoints of the opposing sides of the movable electrode plate 13 are interposed via the flexure portions 14 and 15, respectively. The movable electrode plate 13 is supported on the substrate 11 by the flexure portions 14 and 15 so as to be displaceable in a direction perpendicular to the surface of the substrate 11. A mirror 16 is erected on the surface of the movable electrode plate 13 opposite to the substrate 11.
[0003]
The movable electrode plate 13 and the flexure portions 14 and 15 are formed integrally with the silicon substrate 11, and impurities are mixed into the silicon substrate 11 and the movable electrode plate 13 to give conductivity. Therefore, the part of the substrate 11 facing the movable electrode plate 13 can act as a fixed electrode. A light beam 18 from the incident side optical fiber or optical waveguide 17 is obliquely incident on the mirror 16 parallel to the surface of the substrate 11, and the reflected light is incident on the output side optical fiber or optical waveguide 19. When a voltage is applied between the substrate 11 and the movable electrode plate 13 in this state, an electrostatic attractive force acts between the substrate 11 and the movable electrode plate 13, and the movable electrode plate 13 is displaced toward the substrate 11 side. The light beam 18 from the incident side optical fiber or optical waveguide 17 passes through the mirror 16 without entering the mirror 16 and enters the other outgoing side optical fiber or optical waveguide 21.
[0004]
In this way, depending on whether or not a voltage is applied between the substrate 11 and the movable electrode plate 13, the light beam 18 from the incident side optical fiber or the optical waveguide 17 is emitted from the output side optical fiber or the optical waveguide 19 and the output side optical fiber. The light can be switched and incident on one side of the optical waveguide 21.
[0005]
[Problems to be solved by the invention]
The proposed optical switch shown in FIG. 7 requires a relatively large drive voltage. In order to reduce the drive voltage, it is necessary to lengthen the length between the substrate 11 and the movable electrode plate 13 of the support member including the flexure portions 14 and 15 to be soft, or to increase the area of the movable electrode plate 13. is there. As described above, when the support member including the flexure portion is lengthened or the area of the movable electrode plate 13 is increased, the size of the optical switch is increased. This increase in size leads to a significant increase in size in a large-scale optical switch device (matrix optical switch) in which individual optical switches are arranged in an N × M matrix.
[0006]
An object of the present invention is to provide an optical switch suitable for a matrix optical switch, which can be made compact and can be driven at a low voltage.
[0007]
[Means for Solving the Problems]
According to the present invention, the support for supporting the movable electrode plate on the substrate is formed in a folded beam shape in a plane substantially parallel to the movable electrode plate, and the region occupied by the support and the region occupied by the movable electrode plate are As a whole, a rectangular region is formed.
[0008]
DETAILED DESCRIPTION OF THE INVENTION
FIG. 1 shows an embodiment of the present invention. A movable electrode plate 32 is arranged in parallel to the rectangular substrate 31 with a space therebetween, and the movable electrode plate 32 is supported on the substrate 31 by elastic supports 33 to 36. Each of the supports 33 to 36 is formed in a folded beam shape on substantially the same plane as the plane formed by the movable electrode plate 32. The regions 37 to 40 occupied by the supports 33 to 36 and the region occupied by the movable electrode plate 32 form a substantially square shape as a whole, in this example, a square region.
[0009]
In other words, in this embodiment, rectangular cut portions 41 to 44 are formed at the center of each side of the square movable electrode plate 32, and supports 33 to 36 are arranged on the cut portions 41 to 44, respectively. The outer ends of the bodies 33 to 36 are respectively connected to the fixing portions 45 to 48 standing on the substrate 31 corresponding to the midpoints of the sides of the movable electrode plate 32, and the inner ends are cut portions 41 to 48. 44 is connected to the movable electrode plate 32 at the midpoint of the inner end of 44, and is repeatedly extended in the width direction of the cut portions 41 to 44 between the outer end and the inner end so as to be repeated repeatedly. Support bodies 33 to 36 are configured.
[0010]
In other words, the inner ends of the supports 33 to 36 are connected to the midpoints of the sides of the central square portion 32a of the movable electrode plate 32, respectively, extended outward while being folded back, and connected to the fixed portions 45 to 48, respectively. The Peripheral square portions 32b, 32c, 32d, and 32e of the movable electrode plate 32 are arranged on both sides of these supports 33 to 36, with each apex angle portion of the central square portion 32a being partially shared, and one apex angle portion being common. Yes. Each folding width L2 of the supports 33 to 36 is slightly smaller than each width W1 of the cut portions 41 to 44.
[0011]
The support members 33 to 36 are connected to the upper ends of the fixed portions 45 to 48 on the substrate 31, whereby the movable electrode plate 32 is held with a distance D 1 from the substrate 31, and the folded beam-like structure of the support members 33 to 36. Accordingly, the supports 33 to 36 have elasticity, and the movable electrode plate 32 can be displaced vertically with respect to the substrate 31. The board | substrate 31, the movable electrode plate 32, the support bodies 33-36, and the fixing | fixed parts 45-48 can be comprised as an integral thing.
[0012]
This structure can be made, for example, as shown in FIG. A protective film 51 of SiO ₂ is formed on the silicon substrate 31a as shown in FIG. 2A, and the protective film 51 at positions where the fixing portions 43 to 48 are provided is removed by photolithography to remove small holes as shown in FIG. 2B. 52 is formed. As shown in FIG. 2C, a polycrystalline silicon layer 53 to be a movable electrode plate 32 is formed on the entire surface, and the polycrystalline silicon layer 53 is patterned by photolithography as shown in FIG. A plate 32, supports 33 to 36, and fixing portions 45 to 48 are formed.
[0013]
Next, as shown in FIG. 2E, SiO ₂ protective films 54 and 55 are formed on the entire surface including the movable electrode plate 32 and the bottom surface of the substrate 31a, respectively, and as shown in FIG. Using this as a mask, the substrate 31a is etched with a KOH solution to form a large hole 56 in the portion corresponding to the movable electrode plate 32 as shown in FIG. 2G, leaving only the frame of the substrate 31a. Thereafter, the protective films 51, 54, and 55 of SiO ₂ are removed by chemical etching to obtain a structure in which the movable electrode plate 32 is supported on the frame substrate 31a as shown in FIG. 2H. As shown in FIG. 2I, the inside of the frame-shaped substrate 31a is closed with a silicon substrate 31b from the side opposite to the movable electrode plate 32, and the substrates 31a and 31b are joined. The substrate 31 in FIG. 1 is configured by the substrates 31a and 31b.
[0014]
A mirror 49 is erected on the movable electrode plate 32 as shown in FIG. The mirror surface of the mirror 49 is, for example, 45 degrees with the direction connecting the supports 33 and 34. The movable electrode plate 32 can be displaced toward the substrate 31 by electrostatic attraction. In other words, the movable electrode plate 32 is made of a conductive material, for example, silicon is appropriately mixed with impurities to give conductivity, and the substrate 31 is also mixed with silicon to make conductive materials. A fixed electrode is used. A conductive film may be formed on the substrate 31 to form a fixed electrode.
[0015]
The mirror 49 may be formed integrally with the movable electrode plate 32, or a separate mirror 49 may be fixed to the movable electrode plate 32. The thickness of the movable electrode plate 32 and the supports 33 to 36 is, for example, about 2 to 5 μm.
In this optical switch, similarly to the one shown in FIG. 7, the light beam 18 from the incident side optical fiber or the optical waveguide 17 arranged on the left side in FIG. The light enters the optical fiber or the optical waveguide 19. When a voltage is applied between the movable electrode plate 32 and the substrate 31 and an electrostatic attractive force is applied between them, the movable electrode plate 32 is displaced to the substrate 31 side, and the luminous flux from the incident side optical fiber or the optical waveguide 17 is obtained. Passes through the mirror 49 and enters the opposite output side optical fiber or optical waveguide 21. Therefore, depending on whether or not a voltage is applied between the movable electrode plate 32 and the substrate 31, the light beam from the optical fiber or optical waveguide 17 is switched and incident on the optical fiber or optical waveguide 19 and the optical fiber or optical waveguide 21. Can do.
[0016]
As the dimensions of this optical switch, for example, the length L4 of one side of the movable electrode plate 32 is 1000 μm, the lengths L1 of the supports 33 to 36 are 300 μm, the folding width L2 is 200 μm, the beam width W2 is 10 μm, and the fixed part Each of 45 to 48 is shaped like a prism, its cross section is 50 μm □, and the length L3 of each common part of the central square part 32a and the peripheral square parts 32b to 32e is 30 μm.
[0017]
As described above, a part of the rectangular electrode plate 32 is excised and the supports 33 to 36 are arranged in the excised portion. Therefore, the area of the rectangular electrode plate 32 can be increased, and the supports 33 to 36 are Since it has a folded beam shape, the length of the beam becomes longer than the length L1, and the beam can be made soft. From the idea of FIG. 7, the movable electrode plate is only the central square portion 32a. In this embodiment, peripheral square portions 32b to 32e are arranged on both sides of the support members 33 to 36 and connected to the central square portion 32a. In addition, it can be said that the area of the movable electrode plate 32 is remarkably increased. It can be said as in the above numerical example to 300 × 300 [mu] m ² of the central square portion 32a, 4 × 380 × 380μm ² minutes of four peripheral square portions 32B～32e, the area has increased. Or conversely, it can be said that the movable electrode plate 32 is provided with an excision part, and the supports 33 to 36 are disposed in the excision part, thereby significantly reducing the overall size.
[0018]
In the embodiment of FIG. 1, the movable electrode plate 32 is supported at four points by the supports 33 to 36 at 90 ° angular intervals with respect to the center thereof, but as shown in FIG. 3A, the movable electrode plate 32 is 180 degrees by the two supports 33 and 34. Two points may be supported at angular intervals. A numerical example in this case is shown. The movable electrode plate 32 is a square having a side of 1000 μm (however, there are two rectangular cut portions 41 and 42), the lengths L1 of the supports 33 and 34 are 300 μm, the folding width L2 is 200 μm, and the beam width W2 is 10 μm. The cross section of the fixing portions 45 and 46 is 50 μm □, the distance L3 between the inner ends of the cut portions 41 and 42 is 300 μm, and the width W1 of the cut portions 41 and 42 is 240 μm. In the embodiment shown in FIG. 3A, the substrate 31 is substantially the same as the square shape of the movable electrode plate 32. In other words, the size of the optical switch in the horizontal plane matches the size of the movable electrode plate 32, and the outer shape of the optical switch is 1000 μm 4 in the numerical example.
[0019]
As shown in FIG. 3B, the movable electrode plate 32 can be supported at one point. That is, the two support bodies 33 and 34 are arranged along one side of the movable electrode plate 32, the separated ends of the support bodies 33 and 34 are connected to the substrate 31 via the fixing portions 45 and 46, and the approached end is The connection points are connected to the midpoints of adjacent sides of the movable electrode plate 32 via the connection portion 61. That is, the movable electrode plate 32 is cantilevered by the supports 33 and 34 at the connection point with the connection portion 61. It can be said that a cut portion 62 is formed by cutting a part of the square movable electrode plate 32 along one side, and supports 33 and 34 are arranged in the cut portion 62.
[0020]
In this example, the long side L4 of the movable electrode plate 32 is 1000 μm, the short side L5 is 780 μm, the lengths L1 of the supports 33 and 34 are 450 μm, the folding width L2 is 200 μm, the beam width W1 is 10 μm, and the connection The length L3 of the part 61 is 115 μm, the width W2 is 10 μm, and the cross sections of the fixing parts 45 and 46 are 50 μm □. The outer shape of the optical switch is 1000 μm 4.
[0021]
Although it is one-point support, it can also be configured as shown in FIG. 4A. That is, supports 33 and 34 are arranged along the two long sides of the rectangular movable electrode plate 32, and one ends of the same side of the supports 33 and 34 are connected to the substrate 31 via the fixing portions 45 and 46, respectively. The other ends of the supports 33 and 34 are connected to both ends of the connection beam 62, and the midpoint of the connection beam 62 is connected to the midpoint of one short side of the movable electrode plate 32. In other words, the movable electrode plate 32 is surrounded by the supports 33 and 34 and the connecting beam 62 leaving one short side thereof. It can also be said that both sides of the square movable electrode plate 32 are excised and the supports 33 and 34 are arranged in the excised part. If it does in this way, the length of the support bodies 33 and 34 can be lengthened.
[0022]
A numerical example in this case is shown. Each length L1 of the supports 33 and 34 is 940 μm, the folding width L2 is 200 μm, the beam width W1 is 10 μm, the length L3 of the connecting beam 62 is 810 μm, the width W2 is 10 μm, and the cross section of the fixing portions 45 and 46 is 50 μm □. The long side L4 of the movable electrode plate 32 is 970 μm, and the short side L5 is 560 μm. Each shape of the optical switch is 1000 μm 4.
[0023]
4B, the connecting beam 62 in FIG. 4A may be omitted, and one end of each of the supports 33 and 34 may be connected to both ends of the short side of the movable electrode plate 32 by connecting portions 63 and 64. In this example, the lengths L1 of the supports 33 and 34 are 940 μm, the folding width L2 is 200 μm, the beam width W1 is 10 μm, the lengths L3 of the coupling parts 63 and 64 are 125 μm, the width W2 is 10 μm, and the fixed part. The end faces of 45 and 46 are 50 μm square, the long side L4 of the movable electrode plate 32 is 1000 μm, the short side L5 is 560 μm, and the outer shape of the optical switch is 1000 μm 4.
[0024]
As shown in FIG. 5A, in contrast to FIG. 3B, support bodies 35 and 36 are similarly provided on the opposite side of the support bodies 33 and 34 and the movable electrode plate 32, and the support bodies 35 and 36 are connected. The movable electrode plate 32 can be connected to the movable electrode plate 32 to support the two points.
As shown in FIG. 5B, a square movable electrode plate 32 that is inscribed in the square switch outer shape 65 and rotated 90 degrees is arranged, and each end of the supports 33 to 36 is connected to the midpoint of each side of the movable electrode plate 32. Then, the other ends of the supports 33 to 36 are connected to fixing portions 45 to 48 that stand on the substrate 31 at each corner portion of the optical switch outer shape 65. Each of the supports 33 to 36 effectively uses the space between the movable electrode plate 32 and the optical switch outer shape 65 so that the width of the folded beam is increased on the movable electrode plate 32 side and decreased on the fixed portion side. . Also in this case, it can be said that the corners of the movable electrode plate 32 similar to those of the optical switch outer shape 65 are cut off, and the supports 33 to 36 are arranged so as to fill the cut portions.
[0025]
As shown in FIG. 6, the outer shape of the movable electrode plate 32 is made to substantially coincide with the optical switch outer shape 65, and rectangular cut portions 41 to 44 are provided from the corner portions of the movable electrode plate 32 toward the center. Support bodies 33 to 36 are disposed on 41 to 44, the inner ends of the support bodies 33 to 36 are connected to the movable electrode plate 32, and the outer ends are connected to the substrate 31 via fixing portions 45 to 48.
[0026]
In the above description, a folded beam-like support is used as the support, but any support having elasticity may be used. For example, a flexure part provided with a square part shown in FIG. 7 may be used.
[0027]
【The invention's effect】
According to the present invention, the area occupied by the whole of the movable electrode plate and the area occupied by the support has a rectangular shape, so that a space can be used without waste when a matrix optical switch is configured.
Since the support is arranged at the excision part of the movable electrode plate, it can be made compact and the area of the movable electrode plate can be increased. In other words, the outer area of the optical switch can be effectively used without waste, and it can be driven at low voltage. Is possible.
[Brief description of the drawings]
FIG. 1A is a plan view showing an embodiment of the present invention, and B is a cross-sectional view taken along line AA of FIG. 1A.
2 is a cross-sectional view showing a manufacturing process of the embodiment of FIG. 1;
FIG. 3 is a plan view showing another embodiment of the present invention.
FIG. 4 is a plan view showing still another embodiment of the present invention.
FIG. 5 is a plan view showing still another embodiment of the present invention.
FIG. 6 is a plan view showing still another embodiment of the present invention.
FIG. 7 is a plan view of the optical switch proposed in A, and B is a cross-sectional view taken along the line AA of A. FIG.

Claims

A substrate,
A movable electrode plate that is arranged parallel to the substrate surface and can be displaced perpendicularly to the substrate surface;
A mirror upright on the movable electrode plate;
The movable electrode plate has one end and the other end connected to the substrate, and an elastic support for supporting the movable electrode plate on the substrate,
In an optical switch that applies a voltage between the movable electrode plate and the fixed electrode of the substrate, displaces the movable electrode plate and the mirror in a direction perpendicular to the substrate plane, and passes or reflects a light beam directed to the mirror.
The movable electrode plate has a substantially square shape, a cut portion is formed from the central portion of at least one side toward the central portion, and the support is positioned so as to substantially fill the region in the cut portion.
An optical switch characterized in that an area occupied by the support and an area occupied by the movable electrode plate form a square area as a whole.