JPS59228635A - Optical switching element - Google Patents

Optical switching element

Info

Publication number
JPS59228635A
JPS59228635A JP10356083A JP10356083A JPS59228635A JP S59228635 A JPS59228635 A JP S59228635A JP 10356083 A JP10356083 A JP 10356083A JP 10356083 A JP10356083 A JP 10356083A JP S59228635 A JPS59228635 A JP S59228635A
Authority
JP
Japan
Prior art keywords
electrodes
flat plate
light beam
electrode
switching element
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Pending
Application number
JP10356083A
Other languages
Japanese (ja)
Inventor
Masayuki Fujita
藤田 正幸
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
NEC Corp
Original Assignee
NEC Corp
Nippon Electric Co Ltd
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by NEC Corp, Nippon Electric Co Ltd filed Critical NEC Corp
Priority to JP10356083A priority Critical patent/JPS59228635A/en
Publication of JPS59228635A publication Critical patent/JPS59228635A/en
Pending legal-status Critical Current

Links

Classifications

    • GPHYSICS
    • G02OPTICS
    • G02FOPTICAL DEVICES OR ARRANGEMENTS FOR THE CONTROL OF LIGHT BY MODIFICATION OF THE OPTICAL PROPERTIES OF THE MEDIA OF THE ELEMENTS INVOLVED THEREIN; NON-LINEAR OPTICS; FREQUENCY-CHANGING OF LIGHT; OPTICAL LOGIC ELEMENTS; OPTICAL ANALOGUE/DIGITAL CONVERTERS
    • G02F1/00Devices or arrangements for the control of the intensity, colour, phase, polarisation or direction of light arriving from an independent light source, e.g. switching, gating or modulating; Non-linear optics
    • G02F1/29Devices or arrangements for the control of the intensity, colour, phase, polarisation or direction of light arriving from an independent light source, e.g. switching, gating or modulating; Non-linear optics for the control of the position or the direction of light beams, i.e. deflection

Landscapes

  • Physics & Mathematics (AREA)
  • Nonlinear Science (AREA)
  • General Physics & Mathematics (AREA)
  • Optics & Photonics (AREA)

Abstract

PURPOSE:To correct beam deformation originating from 1 deg. deflection, reduce the decrease in the coupling efficiency of a light beam coupling system, and obtain a device with small insertion loss by attaining 2 deg. deflection to a mutually opposite direction at the time of optical-path switching. CONSTITUTION:A flat plate 4 which has thickness (t) and decreases in refractive index with an electric field or heat is made of, for example, a rutile crystal base plate and has electrodes 5 and 6 on the opposite surfaces spaced by l from the opposite positions in surface directions. A light beam 7 is made incident to the flat plate 4 from near the electrode 5 almost in parallel to the surface of the flat plate 4, and a voltage is impressed between the electrodes 5 and 6 to induce variation in refractive index near right under the electrodes 5 and 6. The light beam 7 projected after being deflected twice is a nearly parallel beam. The distance l and the voltage impressed between the electrodes 5 and 6 are selected properly so that the beam crosses itself almost at the mid-point between the electrodes 5 and 6, thereby suppresses the variation in the diameter of the beam.

Description

【発明の詳細な説明】 本発明は、光線路中に挿入され光路を切り替える光スィ
ッチを構成するだめの光切換素子に関する。
DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an optical switching element that is inserted into an optical path and constitutes an optical switch that switches the optical path.

従来の、光偏向現象を利用した光切換素子としては、特
定の結晶内もしくは結晶表面に弾性波を伝搬させ9弾性
波によって生ずる周期的な屈折率変化を利用したブラッ
グ回折を用いたものが主たるものである。また、最近で
は、電界もしくは熱によると考えられる屈折率勾配を用
いた偏向素子が提案されている(例えば、信学技報0Q
E81−77)。
Conventional optical switching elements that utilize the optical deflection phenomenon mainly use Bragg diffraction, which propagates elastic waves within a specific crystal or on the surface of the crystal and utilizes periodic changes in the refractive index caused by the 9 elastic waves. It is something. In addition, recently, deflection elements using a refractive index gradient thought to be caused by an electric field or heat have been proposed (for example, IEICE Technical Report 0Q
E81-77).

しかしながら、ブラッグ回折型偏向素子では。However, with a Bragg diffractive deflection element.

光ビームの入射角の変動に対し回折光強度が著しく減少
するため、入射角の調整に対する要求精度が厳しくなる
。また最適な入射角で光ビームが入射しても、0次光が
残るため、漏話量低減のために特別な配慮が必要となる
。一方、電界もしくは熱によると考えられる屈折率勾配
を利用したものでは、第7図(、)に示す如く、電極か
らの距離りによシ偏向角θが著しく変化しかつビーム径
が有限であるため、偏向ビームの変形が起こシ、平行ビ
ーム結合系の結合効率が偏向角θの増加に伴なって著し
く低下する。例えば第1図(b)を参照すると。
Since the intensity of the diffracted light decreases significantly as the incident angle of the light beam changes, the accuracy required for adjusting the incident angle becomes stricter. Further, even if the light beam is incident at the optimum angle of incidence, zero-order light remains, so special consideration is required to reduce the amount of crosstalk. On the other hand, in the case of using a refractive index gradient thought to be caused by an electric field or heat, the deflection angle θ changes significantly depending on the distance from the electrode and the beam diameter is finite, as shown in Figure 7 (,). Therefore, the deflected beam is deformed, and the coupling efficiency of the parallel beam coupling system decreases significantly as the deflection angle θ increases. For example, refer to FIG. 1(b).

第1図(a)の様な特性を持つ偏向素子よりなるルチル
結晶基板2にデーム径200μmの光ビーム3を偏向さ
せる場合、熱源なる電極1から0.5 mnの位置に光
ビーム3を入射させた場合では電極1から0.4〜0.
6 mrnの範囲を光ビーム3が通過することになり、
光ビーム3の部分的な偏向角が0.4度〜0.28度ま
で変化する。このため偏向ビームが発散する結果となる
When a light beam 3 with a deme diameter of 200 μm is deflected onto a rutile crystal substrate 2 made of a deflection element having characteristics as shown in FIG. 0.4 to 0.0 from electrode 1.
The light beam 3 will pass through a range of 6 mrn,
The partial deflection angle of the light beam 3 varies from 0.4 degrees to 0.28 degrees. This results in the deflected beam becoming divergent.

本発明の目的は、電界もしくは熱による屈折率勾配を利
用した偏向素子による前記の様なビーム変形を単純な構
造で補償することにより、漏話が少なくビーム変形の少
ない従って平行ビーム結合系の結合効率の低下の少ない
光切換素子を提供することにある。
An object of the present invention is to compensate for the above-mentioned beam deformation caused by a deflection element using a refractive index gradient caused by an electric field or heat with a simple structure, thereby reducing crosstalk and beam deformation, thereby improving the coupling efficiency of a parallel beam coupling system. It is an object of the present invention to provide an optical switching element that exhibits less deterioration in performance.

本発明によれば、電界もしくは熱の印加により屈折率が
減少する素材からなる平板と、この平板の両面にそれぞ
れ形成された第1及び第2の電極とから構成された光切
換素子が得られる。
According to the present invention, an optical switching element can be obtained that is composed of a flat plate made of a material whose refractive index decreases when an electric field or heat is applied, and first and second electrodes formed on both sides of the flat plate, respectively. .

又2本発明によれば、電界もしくは熱の印加により屈折
率が減少する素材からなる平板と、この平板の両面にそ
れぞれ形成された第1及び第2の電極と、前記平板の両
面にそれぞれ前記第1及び第2の電極と対向して形成さ
れた第3及び第4の電極とから構成された光切換素子が
得られる。
According to the second aspect of the present invention, a flat plate made of a material whose refractive index decreases when an electric field or heat is applied, first and second electrodes respectively formed on both sides of the flat plate, and the first and second electrodes formed on both sides of the flat plate, respectively. An optical switching element is obtained which is composed of first and second electrodes and third and fourth electrodes formed to face each other.

以下2図面を参照して本発明の実施例について説明する
Embodiments of the present invention will be described below with reference to two drawings.

第2図(a)は本発明による光切換素子の一実施例の構
成を示した正面断面図である。本実施例の光切換素子は
、電界もしくは熱によシ屈折率が減少する厚さLの平板
4と、平板4上の相対する面上に相対向する位置から面
方向に距離tだけ互いに離れだ位置に形成された電極5
および6から成る。
FIG. 2(a) is a front sectional view showing the structure of one embodiment of the optical switching element according to the present invention. The optical switching element of this embodiment has a flat plate 4 having a thickness L whose refractive index decreases due to an electric field or heat, and a flat plate 4 which is spaced from each other by a distance t in the plane direction from opposing positions on opposing surfaces of the flat plate 4. The electrode 5 formed at the
and 6.

平板4は2例えばルチル結晶基板からなる。以下本発明
の動作について説明する。
The flat plate 4 is made of, for example, a rutile crystal substrate. The operation of the present invention will be explained below.

光ビーム7を、電極5の近傍から電極5および6の形成
された平板40面とほぼ平行になる様に平板4に入射さ
せ、電極5および6に電圧を印加して電極5および6の
直下近傍に屈折率変化を誘起する。この電極直下近傍に
誘起された屈折率変化は、電極直下の屈折率が減少する
ため、平板4内部に向って増加する傾向にある。しだが
って電極直下近傍を通過するビームは平板内部へ向かっ
て偏向をうける。
A light beam 7 is made to enter the flat plate 4 from near the electrode 5 so as to be almost parallel to the plane of the flat plate 40 on which the electrodes 5 and 6 are formed, and a voltage is applied to the electrodes 5 and 6 so that the light beam 7 is directly below the electrodes 5 and 6. Induces a refractive index change in the vicinity. This refractive index change induced in the vicinity directly under the electrode tends to increase toward the inside of the flat plate 4 because the refractive index directly under the electrode decreases. Therefore, the beam passing directly under the electrode is deflected toward the inside of the flat plate.

さて、入射した光ビーム7は、まず電極5近傍で偏向を
うけ平板4内部へ向うが、前述の様に偏向角01は部分
的に異なシ、第2図(b)に示すように、電極5に近い
部分から十〇11度〜+012度まで変化する(ただし
θII)θ12)。このとき電極5に印加する電圧と、
距離tを適当に選べば、偏向ビームは第2図(a)の破
線に示すように平板4の内部で交叉し、電極6の直下へ
導かれる。電極6の直下へ導かれたビームは前記のよう
にその内部で交叉しているため、電極5に近い部分が電
極6の最も近い部分を通過することになる。しだがって
電極6近傍において受ける偏向はその偏向角θ2が第2
図(b)に示すように、−021度〜−022度まで連
続的に変化し+011度の偏向をうけだ部分に対し一〇
21度、十〇12度の偏向をうけた部分に対し一〇22
度となる(ただし、1−02.1>1−02□1)。
Now, the incident light beam 7 is first deflected near the electrode 5 and then heads into the flat plate 4, but as mentioned above, the deflection angle 01 is partially different, and as shown in FIG. It changes from a part close to 5 to 1011 degrees to +012 degrees (however, θII) θ12). The voltage applied to the electrode 5 at this time,
If the distance t is appropriately selected, the deflected beams intersect inside the flat plate 4, as shown by the broken line in FIG. 2(a), and are guided directly below the electrode 6. Since the beam guided directly below the electrode 6 intersects within it as described above, the portion closest to the electrode 5 passes through the portion closest to the electrode 6. Therefore, the deflection angle θ2 of the deflection received near the electrode 6 is the second
As shown in figure (b), it changes continuously from -021 degrees to -022 degrees, and the part that receives a deflection of +011 degrees is 1021 degrees, and the part that is deflected 1012 degrees is 〇22
degree (however, 1-02.1>1-02□1).

このとき、電極6に印加する電圧を適当に選べばビーム
内の各部についてθ1度〜02度=0度とすることがで
きる。このため、2回の偏向を受けて出射する光ビーム
7は、はぼ平行ビームとなる。
At this time, if the voltage applied to the electrode 6 is appropriately selected, it is possible to set θ1 degrees to 02 degrees = 0 degrees for each part within the beam. Therefore, the light beam 7 that is emitted after being deflected twice becomes a nearly parallel beam.

残る問題としては、ビーム径の変動が考えられるが、距
離tと電極5および6に印加する電圧を適当に選び、ビ
ーム内部の交叉が電極5および6のほぼ中間点で起こる
ようにすれば、入出射ビームのビーム径変動を抑えるこ
とができる。
The remaining problem may be variations in the beam diameter, but if the distance t and the voltages applied to electrodes 5 and 6 are appropriately selected so that the intersection within the beam occurs approximately at the midpoint between electrodes 5 and 6, then Fluctuations in the beam diameter of the input and output beams can be suppressed.

第3図は本発明による光切換素子の他の一実施例を示し
だ正面断面図であシ、第2図(a)の実施例のものは1
×2光スイツチ用光切換素子であるのに対し1本実施例
のものは2×2光スイツチ用光切換素子である。本実施
例の光切換素子は、電界もしくは熱により屈折率が減少
する厚さtの平板14と、平板14上の相対する面上に
相対向する位置から面方向に距離tだけ互いに離れた位
置に形成された電極8および9と、平板14上の相対す
る面上にそれぞれ電極8および9と対向して形成された
電極10及び11から成る。入射する光ビームのうち、
一方の光ビーム12を、電極8の近傍から電極8〜11
の形成された平板140面とほぼ平行になるように平板
14に入射させ、他方の光ビーム13を、電極10の近
傍から電極8〜11の形成された平板140面とほぼ平
行になるように平板】4に入射させる。以下の動作は。
FIG. 3 is a front sectional view showing another embodiment of the optical switching element according to the present invention, and the embodiment shown in FIG.
This is an optical switching element for a ×2 optical switch, whereas the optical switching element of this embodiment is an optical switching element for a 2×2 optical switch. The optical switching element of this embodiment includes a flat plate 14 with a thickness t whose refractive index is reduced by an electric field or heat, and a position on opposing surfaces of the flat plate 14 that is spaced apart from each other by a distance t in the plane direction from opposing positions. and electrodes 10 and 11 formed on opposite surfaces of a flat plate 14 to face the electrodes 8 and 9, respectively. Of the incident light beam,
One of the light beams 12 is directed from the vicinity of the electrode 8 to the electrodes 8 to 11.
The other light beam 13 is directed from near the electrode 10 so as to be almost parallel to the flat plate 140 surface on which the electrodes 8 to 11 are formed. Flat plate】4. The following operation is.

第2図の例と同様であるので、省略する。Since this is the same as the example shown in FIG. 2, the explanation will be omitted.

第4図は、第2図に示した1×2光スイツチ用光切換素
子の適用例を示す正面断面図である。光切換素子を構成
する電極22及び23に電圧を印加しない場合は、光フ
ァイバ19からロッドレンズ16を介して電極22の近
傍から光切換素子を構成するルチル結晶基板15に入射
した光ビームは、そのままルチル結晶基板15内を直進
して通過してルチル結晶基板15の端面から出射し、こ
の出射した光ビームはロッドレンズ17を介して光ファ
イバ20に結合され、光フアイバ20内を伝送していく
。一方、電極22及び23に電圧を印加した場合、光フ
ァイバ19からロッドレンズ16を介して電極22の近
傍からルチル結晶基板15に入射した光ビームは、電極
22の近傍で1回目の偏向をうけてルチル結晶基板15
の内部を通シ、更に電極23の近傍で2回目の偏向をう
けて、ルチル結晶基板15の電極23の近傍の端面から
出射し、この出射した光ビームはロッドレンズ18を介
して光ファイバ21に結合され、光フアイバ21内を伝
送していく。
FIG. 4 is a front sectional view showing an example of application of the optical switching element for a 1×2 optical switch shown in FIG. 2. When no voltage is applied to the electrodes 22 and 23 that constitute the optical switching element, the light beam that enters the rutile crystal substrate 15 that constitutes the optical switching element from the vicinity of the electrode 22 from the optical fiber 19 via the rod lens 16 is as follows. The light beam passes straight through the rutile crystal substrate 15 and is emitted from the end face of the rutile crystal substrate 15, and this emitted light beam is coupled to the optical fiber 20 via the rod lens 17 and transmitted through the optical fiber 20. go. On the other hand, when a voltage is applied to the electrodes 22 and 23, the light beam that enters the rutile crystal substrate 15 from the vicinity of the electrode 22 from the optical fiber 19 via the rod lens 16 is deflected for the first time in the vicinity of the electrode 22. Rutile crystal substrate 15
The light beam passes through the inside of the rutile crystal substrate 15, is deflected a second time near the electrode 23, and is emitted from the end face of the rutile crystal substrate 15 near the electrode 23. and is transmitted through the optical fiber 21.

本発明者は、実際に、基板素材として大きさI I) 
X 30 mmで厚さi mmのルチル結晶を用い、電
極としてNi −Crによる薄膜ヒータ(巾i mrn
 、長損は4 dBであり、光切換素子のビーム変形補
償効果によ、91.5 dBのビーム結合損失の改善が
あったことを確認した。
The present inventor actually used the size II as a substrate material.
A thin film heater (width i mrn
The long-term loss was 4 dB, and it was confirmed that the beam coupling loss was improved by 91.5 dB due to the beam deformation compensation effect of the optical switching element.

以上の説明で明らか々ように2本発明に係る光切換素子
では光路切替の際、相反する方向へ2度偏向させるだめ
、1度の偏向によって生ずるビーム変形を補償する効果
が期待できる。従って偏向による光ビーム結合系の結合
効率の低下が緩和され、低挿入損のデバイスが作製でき
る。
As is clear from the above description, the optical switching element according to the present invention can be expected to have the effect of compensating for the beam deformation caused by one degree of deflection by deflecting the beam twice in opposite directions when switching the optical path. Therefore, the decrease in coupling efficiency of the optical beam coupling system due to deflection is alleviated, and a device with low insertion loss can be manufactured.

【図面の簡単な説明】[Brief explanation of the drawing]

第1図は従来の屈折率勾配を利用した偏向素子の偏向状
態を説明した図、第2図は本発明による光切換素子の一
実施例の構成を示した正面断面図および偏向状態説明図
、第3図は本発明による光切換素子の他の一実施例の構
成を示した正面断面図、第4図は第2図に示しだ光切換
素子の適用例を示しだ正面断面図である。 1・・・電極、2・・・ルチル結晶基板、3・・・光ビ
ーム。 4・・・平板、5,6・・・電極、7・・・光ビーム、
8〜11・・・電極、12.13・・・光ビーム、14
・・・平板、15・・・ルチル結晶基板、16・・・1
8・・・ロッドレンズ。 19〜21・・・光ファイバ、22.23・・・電極。 →D(mm) (Q) 第1図
FIG. 1 is a diagram explaining the deflection state of a conventional deflection element using a refractive index gradient, and FIG. 2 is a front sectional view and a deflection state explanatory diagram showing the configuration of an embodiment of the optical switching element according to the present invention. FIG. 3 is a front sectional view showing the structure of another embodiment of the optical switching element according to the present invention, and FIG. 4 is a front sectional view showing an example of application of the optical switching element shown in FIG. 2. 1... Electrode, 2... Rutile crystal substrate, 3... Light beam. 4... Flat plate, 5, 6... Electrode, 7... Light beam,
8-11... Electrode, 12.13... Light beam, 14
...Flat plate, 15...Rutile crystal substrate, 16...1
8...Rod lens. 19-21... Optical fiber, 22.23... Electrode. →D (mm) (Q) Fig. 1

Claims (1)

【特許請求の範囲】 1 電界もしくは熱の印加により屈折率が減少する素材
からなる平板と、該平板の両面にそれぞれ形成された第
1及び第2の電極とから構成された光切換素子。 2、 電界もしくは熱の印加によシ屈折率が減少する素
材からなる平板と、該平板の両面にそれぞれ形成された
第1及び第2の電極と、前記平板の両面にそれぞれ前記
第1及び第2の電極と対向して形成された第3及び第4
の電極とから構成された光切換素子。
[Scope of Claims] 1. An optical switching element comprising a flat plate made of a material whose refractive index decreases upon application of an electric field or heat, and first and second electrodes formed on both sides of the flat plate, respectively. 2. A flat plate made of a material whose refractive index decreases when an electric field or heat is applied, first and second electrodes formed on both sides of the flat plate, and first and second electrodes formed on both sides of the flat plate, respectively. The third and fourth electrodes are formed opposite to the second electrode.
An optical switching element consisting of an electrode.
JP10356083A 1983-06-11 1983-06-11 Optical switching element Pending JPS59228635A (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
JP10356083A JPS59228635A (en) 1983-06-11 1983-06-11 Optical switching element

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
JP10356083A JPS59228635A (en) 1983-06-11 1983-06-11 Optical switching element

Publications (1)

Publication Number Publication Date
JPS59228635A true JPS59228635A (en) 1984-12-22

Family

ID=14357194

Family Applications (1)

Application Number Title Priority Date Filing Date
JP10356083A Pending JPS59228635A (en) 1983-06-11 1983-06-11 Optical switching element

Country Status (1)

Country Link
JP (1) JPS59228635A (en)

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