JPS6310125A - Plane type optical control element - Google Patents
Plane type optical control elementInfo
- Publication number
- JPS6310125A JPS6310125A JP15640486A JP15640486A JPS6310125A JP S6310125 A JPS6310125 A JP S6310125A JP 15640486 A JP15640486 A JP 15640486A JP 15640486 A JP15640486 A JP 15640486A JP S6310125 A JPS6310125 A JP S6310125A
- Authority
- JP
- Japan
- Prior art keywords
- layer
- light
- electric field
- light beam
- waveguide
- 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.)
- Granted
Links
- 230000003287 optical effect Effects 0.000 title claims abstract description 16
- 230000005684 electric field Effects 0.000 claims abstract description 27
- 239000004065 semiconductor Substances 0.000 claims abstract description 14
- 238000005253 cladding Methods 0.000 claims description 3
- 238000010521 absorption reaction Methods 0.000 abstract description 27
- 239000000758 substrate Substances 0.000 abstract description 12
- 230000003247 decreasing effect Effects 0.000 abstract 1
- 230000008859 change Effects 0.000 description 11
- 229910001218 Gallium arsenide Inorganic materials 0.000 description 10
- 230000008033 biological extinction Effects 0.000 description 5
- 230000000694 effects Effects 0.000 description 5
- 239000000463 material Substances 0.000 description 5
- 238000000862 absorption spectrum Methods 0.000 description 3
- 230000031700 light absorption Effects 0.000 description 3
- 230000033001 locomotion Effects 0.000 description 3
- 238000000034 method Methods 0.000 description 3
- 229910000980 Aluminium gallium arsenide Inorganic materials 0.000 description 2
- 229910000530 Gallium indium arsenide Inorganic materials 0.000 description 2
- 230000004888 barrier function Effects 0.000 description 2
- 235000012489 doughnuts Nutrition 0.000 description 2
- 238000004519 manufacturing process Methods 0.000 description 2
- 229920002120 photoresistant polymer Polymers 0.000 description 2
- 230000004044 response Effects 0.000 description 2
- 229910052581 Si3N4 Inorganic materials 0.000 description 1
- 230000008901 benefit Effects 0.000 description 1
- 230000005540 biological transmission Effects 0.000 description 1
- 239000000969 carrier Substances 0.000 description 1
- 238000006243 chemical reaction Methods 0.000 description 1
- 239000003795 chemical substances by application Substances 0.000 description 1
- 230000001186 cumulative effect Effects 0.000 description 1
- 230000007423 decrease Effects 0.000 description 1
- 238000005530 etching Methods 0.000 description 1
- 230000008020 evaporation Effects 0.000 description 1
- 238000001704 evaporation Methods 0.000 description 1
- 230000005284 excitation Effects 0.000 description 1
- 239000012535 impurity Substances 0.000 description 1
- 239000004973 liquid crystal related substance Substances 0.000 description 1
- 230000000873 masking effect Effects 0.000 description 1
- 230000005693 optoelectronics Effects 0.000 description 1
- 230000000704 physical effect Effects 0.000 description 1
- 238000005268 plasma chemical vapour deposition Methods 0.000 description 1
- 230000008569 process Effects 0.000 description 1
- 238000001228 spectrum Methods 0.000 description 1
- 230000005428 wave function Effects 0.000 description 1
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- Optical Integrated Circuits (AREA)
Abstract
Description
【発明の詳細な説明】
（産業上の利用分野）
本発明は基板にほぼ垂直な方向に元の人、出射を行なう
平面型光制御素子に関するものである。DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to a planar light control element that emits light in a direction substantially perpendicular to a substrate.
（従来の技術）
近年、光信号ｔ−光のままで処理する光変換、光コンピ
ユーテイング等の研究が盛んになっている。(Prior Art) In recent years, research into optical conversion, optical computing, etc., which processes optical signals as they are (t-light), has become active.
元の持つ並列処理性、画偉信号の取シ扱い等１考えると
、１つの面内に２次元アレイ状元信号処理デバイスを配
置し、面に垂直な方向に光信号の入出射を行なう、謂ゆ
る平面型光制御素子が重要なデバイスとなる。Considering the parallel processing ability of the original, the handling of image signals, etc.1, it is possible to arrange a two-dimensional array of original signal processing devices in one plane and input and output optical signals in the direction perpendicular to the plane. Planar light control elements will become important devices.
従来このような千面聾元制御素子としては液晶や強誘電
体の電気光学効果を利用した元シャッタがあったが、動
作が遅い、高い駆動電圧が必要などの欠点があり、広く
用いられるには至っていない。また、雑誌アプライド・
フィツクス・レターズ（Ａｐｐｌｉｅｄ Ｐｈｙｓｉｃ
ｓ Ｌｅｔｔｅｒｓ）第４１巻。Conventional shutters that utilize the electro-optical effect of liquid crystals or ferroelectrics have been used as such control elements for a thousand-sided deafening element, but they have drawbacks such as slow operation and the need for high drive voltage, so they are not widely used. has not yet been reached. In addition, the magazine Applied
Fixture Letters (Applied Physics
s Letters) Volume 41.
１９８２年、４１３〜４１５頁及び同じ雑誌の第４４巻
。1982, pp. 413-415 and volume 44 of the same magazine.
１９８４年１６〜１８頁に述べられているように半導体
層や多重量子井戸構造に電界を印加した際の吸収端の移
動（電界吸収効果）を利用した素子も報告されている。As described in 1984, pp. 16-18, devices that utilize the movement of absorption edges (electric field absorption effect) when an electric field is applied to a semiconductor layer or multiple quantum well structure have also been reported.
この素子は累励起の効果を利用しているため本質的に応
答速度が速く、半導体材料を用いているので他の高速電
子デバイス、元デバイスと集積化できる等の利点を持っ
ている。Since this element utilizes the effect of cumulative excitation, its response speed is inherently fast, and since it uses a semiconductor material, it has the advantage of being able to be integrated with other high-speed electronic devices and original devices.
第４図は、この素子の断面図を示すものである。FIG. 4 shows a cross-sectional view of this element.
第４図を用いてまずこの素子の製作について説明する。First, the fabrication of this element will be explained using FIG. 4.
ｎ＋−ＧａＡｓ基板４１上に分子線エピタキシャル（Ｍ
ＢＥ）法によりｎ＋−Ａ／ＧａＡｓコンタクト層４２．
１−ＧａＡｓ／ＡｌＧａＡｓ多重量子井戸（ＭＱＷ）層
４３ 、 Ｐ”−ＡＡ！ＧａＡｓ ：Ｉ７タクト層４４
゜全成長する。このウェハのエピタキシャル層側円形（
径９５μｆＦ１）のフォトレジストマスクラ形成し、エ
ツチングによ’）ｎ”−ＡＩＧａＡｓ コンタクト層４
２の途中迄を除去し、円柱状のメサを形成する。次にプ
ラズマＣＶＤ法により５ＩｓＮ４膜４６をエピタキシャ
ル層側に成膜しメサ上面の５ｉｘＮ４膜を７オトレジス
ト１マスクにリング状に除去し、続いてＡｕの蒸着、リ
フトオフによりリング状の電極４５を形成する。ウェハ
の裏面にはＡｕ５ｕｉ蒸着後、エピタキシャル層側の円
柱状のメサの真下の部分のＡｕＳｎを除去して出来た電
極４８をマスクとしてｎ ＋−Ｇ ａ Ａ ｓ基板を除
去する。Molecular beam epitaxial (M
n+-A/GaAs contact layer 42.
1-GaAs/AlGaAs multiple quantum well (MQW) layer 43, P”-AA!GaAs:I7 tact layer 44
゜Full growth. The epitaxial layer side of this wafer is circular (
A photoresist masking layer with a diameter of 95 μf F1) is formed and etched to form an n”-AIGaAs contact layer 4.
Part 2 is removed up to the middle to form a cylindrical mesa. Next, a 5IsN4 film 46 is formed on the epitaxial layer side by plasma CVD, and the 5ixN4 film on the upper surface of the mesa is removed in a ring shape using a 7-photoresist 1 mask, followed by Au evaporation and lift-off to form a ring-shaped electrode 45. . After Au5ui is deposited on the back surface of the wafer, the n + -GaAs substrate is removed using the electrode 48 formed by removing the AuSn directly below the columnar mesa on the epitaxial layer side as a mask.
ここで用いているＭＱＷ構造は半導体層をそれよシパン
ドギャップの広い半導体ではさんだ量子井戸（ＱＷ）を
層厚方向に多重に有するもので、各ＱＷ内での電子、正
孔の２次元化によシバルクとは異なる物性を示すことか
ら注目されているものである。具体的にはそれぞれ９５
Ａ厚のＧ ａ Ａ ｓウェルとＡＩ Ｇ ａ Ａ ｓバ
リアの５０周期から成る構造を用いている。The MQW structure used here has multiple quantum wells (QWs) in the layer thickness direction, with a semiconductor layer sandwiched between semiconductors with a wide band gap, and electrons and holes within each QW are two-dimensional. It is attracting attention because it exhibits physical properties that are different from Yoshibulk. Specifically, 95 each
A structure consisting of 50 periods of A-thick GaAs wells and AI GaAs barriers is used.
ＧａＡｓ／ＡＪＧａＡｓ ＭＱＷではそのポテンシャ
ル構造により、電子、正孔共にＧ ａ Ａ ｓウェル内
に閉じ込められる。電子、正孔それぞれの井戸深さは価
電子帯伝導帯のバンド不連続量により決まる。In GaAs/AJGaAs MQW, both electrons and holes are confined within the GaAs well due to its potential structure. The depth of each well for electrons and holes is determined by the amount of band discontinuity in the valence band conduction band.
井戸深さが充分深いと近似すれば層厚方向をｚ方向とし
て、電子の全エネルギーは２方向に量子化となる。但し
ここに、上はディラック定数２ｍ“は電子の有効質量、
ｎは量子数（ｎ＝１．２，３゜・・・）、Ｌ２はウェル
幅である。バルク状態での電子のエネルギーは全運動１
ｔ−ｐとしてｐ／２ｍ”と書ける。これに対応するエネ
ルギー波動の波長はドブロイ波長λ。と呼ばれ、λｏ＝
ｈ／ｐ （ｈ＝ニブランク数）と書けるが、ＱＷ構造に
於て量子効化が顕著になるためにはＬ２≦λ。であるこ
とが必要である。今考えている系ではλ。は２００〜Ａ
Ｉ Ｇ ａ Ａ ｓバリγ層はあまシ薄いとウェル間
の結合が生じるため９５Ａとして各ウェル間の結合が起
きない構造としている。Approximating that the well depth is sufficiently deep, the total energy of electrons is quantized in two directions, with the layer thickness direction being the z direction. However, here, the Dirac constant 2m" above is the effective mass of the electron,
n is the quantum number (n=1.2, 3°...), and L2 is the well width. The energy of an electron in the bulk state is the total motion 1
It can be written as "p/2m" as t-p.The wavelength of the energy wave corresponding to this is called de Broglie wavelength λ. λo=
It can be written as h/p (h=Nyblank number), but in order for the quantum effect to become significant in the QW structure, L2≦λ. It is necessary that In the system we are currently considering, λ. is 200~A
If the IGaAs barrier γ layer is too thin, bonding will occur between the wells, so the structure is set to 95A so that bonding between the wells does not occur.
第４図に示した構造はｐ −ｉ −ｎダイオード構造と
なっておシ、電極４６．４８間に逆バイアスを印加する
とｉ−ＭＱＷ層４３に有効に電界が印加される。この電
界によｆｉＭＱＷの吸収端は長波長側に移動するので、
無電界時の吸収端よシ長波長側の元に対しては、電界の
印加によｐＭＱＷ層の吸収が増大する。従って、円柱状
メサ上部のＳｉ３Ｎ４膜の中心部４６ａに層に垂直に光
を通すと、（吸収端よシ長波長の元）電界の印加によシ
この光を変調することができる。The structure shown in FIG. 4 is a p-i-n diode structure, and when a reverse bias is applied between the electrodes 46 and 48, an electric field is effectively applied to the i-MQW layer 43. This electric field moves the absorption edge of fiMQW toward longer wavelengths, so
For elements on the long wavelength side of the absorption edge in the absence of an electric field, the absorption of the pMQW layer increases by applying an electric field. Therefore, when light is passed perpendicularly to the central portion 46a of the Si3N4 film above the cylindrical mesa, the light can be modulated by applying an electric field (at a longer wavelength than the absorption edge).
（発明が解決しようとする問題点）
しかしながら、これらの素子では元の透過方向と電界の
印加方向が同一であるため、吸収長（ここでは層厚）を
長くすると電界強度が強くできず、逆に電界強度を高く
するため吸収長を短くすると消光比が充分とれない。報
告されているデータによれば電圧１０■程度で消光比は
数ｄＢ程度しかとれておらず、実用に供するのは難しい
。(Problem to be solved by the invention) However, in these elements, since the original transmission direction and the direction of electric field application are the same, increasing the absorption length (here, layer thickness) does not increase the electric field strength, and vice versa. If the absorption length is shortened to increase the electric field strength, a sufficient extinction ratio cannot be obtained. According to reported data, the extinction ratio is only about several dB at a voltage of about 10 µ, making it difficult to put it to practical use.
本発明はこのような従来の平面型光制御素子の欠点を除
き、低電圧で高消去比がとれ、しかも高速動作が可能な
平面型光制御素子を提供すること：である。An object of the present invention is to provide a planar light control element which eliminates the drawbacks of the conventional planar light control element, has a high erasing ratio at low voltage, and can operate at high speed.
（問題を解決するための手段）
本発明による平面型光制御素子は、ドブロイ波長程度の
厚みの第１の半導体層を前記第１の半導体層よシもバン
ドギャップの広い第２の半導体層ではさんだ量子井戸を
層厚方向に多重に有する多重量子井戸構造と回析格子の
形成された層とを導波路層、クラッド層の少なくとも１
部に含む半導体光導波路と前記多重量子井戸構造に電界
を印加する手段と前記光導波路の回析格子が形成された
部分に各層に略垂直に光を導く手段とから成ることを特
徴とする。(Means for Solving the Problem) In the planar light control element according to the present invention, a first semiconductor layer having a thickness of approximately the de Broglie wavelength is formed into a second semiconductor layer having a wider bandgap than the first semiconductor layer. A multi-quantum well structure having multiple sandwiched quantum wells in the layer thickness direction and a layer on which a diffraction grating is formed are at least one of the waveguide layer and the cladding layer.
A semiconductor optical waveguide included in the optical waveguide and a means for applying an electric field to the multi-quantum well structure, and a means for guiding light substantially perpendicularly to each layer to a portion of the optical waveguide where a diffraction grating is formed.
（作用）
本発明は量子井戸（ＱＷ）構造の電界による複素屈折率
ｎ＝ｎ−ｊｋの変化を利用したものである。(Function) The present invention utilizes a change in the complex refractive index n=n-jk due to an electric field in a quantum well (QW) structure.
まずこの電界による複素屈折率ｎの変化について説明す
る。First, the change in the complex refractive index n due to this electric field will be explained.
第２図はＧａＡｓ／ＡＩＧａＡｓＭＱＷ構造に電界Ｅ″
ｌｒ：ＭＱＷの各ＱＷに垂直に印加した際の光吸収スペ
クトルの変化を測定した結果である。電界Ｅによ＃）Ｑ
Ｗのポテンシャル構造が傾き、量子準位の移動、電子・
正孔波動関数のＱＷ内でのかたよりが生じるため電界Ｅ
ｉ印加しない時の吸収端λｆ近傍よシ長波長側では吸収
係数の増大、吸収端より短波長側では逆に吸収係数の減
少が生じる。伺、ＭＱＷ構造では半導体本来の基礎吸収
スペクトルに、エキシトン吸収ピークが重なっておシ、
更に不純物等による吸収端での吸収Ｉ杭列きもあるため
、厳密には吸収端λｆの位置は特定しにくい。Figure 2 shows the electric field E'' in the GaAs/AIGaAs MQW structure.
lr: This is the result of measuring the change in the light absorption spectrum when applying light perpendicularly to each QW of MQW. Due to the electric field E#)Q
The potential structure of W is tilted, the quantum level moves, the electrons
Because the hole wave function is shifted within the QW, the electric field E
When no i is applied, the absorption coefficient increases on the longer wavelength side near the absorption edge λf, and conversely, the absorption coefficient decreases on the shorter wavelength side than the absorption edge. In the MQW structure, the exciton absorption peak overlaps with the fundamental absorption spectrum inherent in semiconductors.
Furthermore, since there is also an absorption I pile row at the absorption edge due to impurities, etc., it is difficult to specify the position of the absorption edge λf in a strict sense.
ここでは吸収スペクトラムの急激に変化する部分の接線
と吸収係数０の直線の交点の波長を吸収端と呼ぶが厳密
には意味はない。一方、複素屈折率富＝ｎ−ｊｋのｋは
吸収係数αとに＝λａ／４π（但しλは波長）の関係が
あハ更に複素屈折率ｎの実部ｎと虚部にはクラマース・
クローニツヒの関係によシ関係付けられている。このた
め、上述のような吸収係数αの変化は複素屈折率実部ｎ
の変化ももたらす。Here, the wavelength at the intersection of the tangent to the rapidly changing portion of the absorption spectrum and the straight line with the absorption coefficient of 0 is called the absorption edge, but it has no strict meaning. On the other hand, k of the complex refractive index wealth = n-jk has a relationship with the absorption coefficient α of = λa/4π (where λ is the wavelength).Furthermore, the real part n and imaginary part of the complex refractive index n have the Kramers equation.
It is related by Kronitz's relationship. Therefore, the change in the absorption coefficient α as described above is due to the real part of the complex refractive index n
It also brings about changes.
第３図はこのような関係をもとにある電界強度に於ける
吸収係数変化（Δα）、屈折率変化（Δｎ）のスペクト
ルの概要を示したものである。第３図に示すようにλｆ
くλくλ！の範囲ではΔαは正。FIG. 3 shows an outline of the spectrum of absorption coefficient change (Δα) and refractive index change (Δn) at a certain electric field intensity based on such a relationship. As shown in Figure 3, λf
Kuλkuλ! Δα is positive in the range of .
Δｎは負、λ１くλではΔα、Δｎ共に正の符号を持ち
その絶対値は１０−２のオーダにも達する。Δn is negative, and at λ1 and λ, both Δα and Δn have positive signs, and their absolute values reach the order of 10 −2 .
一方１元導波路の導波路層若しくはクラッド層に形成し
た回析格子はグレーティング・カプラとして働くことが
知られており、その周期Ａが波長λとの間に次の関係（
ブラッグ条件）を持つ時、はぼ層に垂直に入射する元に
対するカプラとなる。On the other hand, it is known that a diffraction grating formed in the waveguide layer or cladding layer of a one-dimensional waveguide acts as a grating coupler, and the relationship between its period A and wavelength λ is as follows (
Bragg condition), it becomes a coupler for the element that is incident perpendicularly to the layer.
Ａ＝ｍλ７２ｇ
ここにｎ１１１元導波路の実効屈折率、ｍは偶数である
。Ａが１定としてｎｙが変化したとするとブラッグ条件
を満たす波長の変化はｄ２！λ＝ｄｎｙ７ｎ。A=mλ72g where the effective refractive index of the n111-element waveguide, m, is an even number. Assuming that A is constant and ny changes, the change in wavelength that satisfies the Bragg condition is d2! λ=dny7n.
となる。従ってグレーティング・カプラの光導波路をＭ
ＱＷ構造により作り電界印加によりｎｐｔ：１０ 変
化させればλを例えば１．３μｍの近傍で１００Ａ程度
以上変化させることができる。入射光波長がブラッグ条
件を満足しなければ光導波路に結合されず入射光はその
まま透過する。一方、ｎｇを変化させることによシ入射
光がブラッグ条件を満足するようにすれば入射光は光導
波路に導波光として結合され各層を透過して出力はされ
ない。becomes. Therefore, the optical waveguide of the grating coupler is M
By making a QW structure and changing npt:10 by applying an electric field, it is possible to change λ by about 100 A or more in the vicinity of 1.3 μm, for example. If the wavelength of the incident light does not satisfy the Bragg condition, the incident light will not be coupled to the optical waveguide and will pass through as is. On the other hand, if the incident light is made to satisfy the Bragg condition by changing ng, the incident light is coupled to the optical waveguide as guided light, passes through each layer, and is not output.
つまジグレーティング・カブ２を平面型の元ゲート素子
として用いることができる訳で、ｎｇ の変化を得る丸
めにＭＱＷの電界による屈折率変化を利用すれば効果が
大きく応答速度が速いため高速／高効率の素子を得るこ
とができる。本発明は以上のような原理に基づくもので
ある。The Tsumji grating Cub 2 can be used as a planar original gate element, and if the refractive index change due to the electric field of MQW is used for rounding to obtain the change in ng, the effect is large and the response speed is fast, so it can be used at high speeds/high speeds. A highly efficient element can be obtained. The present invention is based on the above principle.
（実施例）
第１図は本発明による平面型光制御素子の１実施例の断
面構造を示すものである。ここではＩｎＧａＡｓＰ／Ｉ
ｎＰ素材料を用いた場合について示しである。まず第１
図を用いて本実施例の製作について説明する。ｎ＋−Ｉ
ｎＰ基板１上にｎ＋−ＩｎＰバッフ丁層２を介して１−
ＩｎＧａＡｓＰ／ＩｎＰＭＱＷ元導波層３ ＋ ｐ Ｉ
ｎＧａＡｓＰ層４’１ＶＰＥ法によシ成長した。１−Ｉ
ｎＧａＡｓＰ／ＩｎＰ ＭＱＷ元導良導波層３ｐ −Ｉ
ｎＧａＡｓＰ層４の吸収端はそれぞれ１．３ ａｍ 、
１．１５ μｍである。次にｐ−ＩｎＧａＡｓＰ層４
上にＨｅ−Ｃｄレーザの２Ｘ束干渉露光法によ）回析格
子５を形成する。１−ＩｎＧａＡｓＰ／ＩｎＰＭＱＷ元
導波層３ｔ−導波層とする光導波路３ｔ＝１．３５μｍ
に於ける実効屈折率ｎｙは３．４であり、回析格子５の
周期Ａは２次のブラッグ条件を満足するように約４００
ＯＡとしている。次にｐ−ＩｎＧａＡｓＰ層４上にｐ型
オーム性電極６となるＡｕ／ Ｚ ｕをドーナツ状に形
成し、ドーナツの外部をエツチングによシ除去し円筒状
のメブ７を形成する。最後にｎ”−ＩｎＰ基板１にメサ
７の直下の部分を除いてｎ型オーム性電極８を形成した
。(Embodiment) FIG. 1 shows a cross-sectional structure of one embodiment of a planar light control element according to the present invention. Here, InGaAsP/I
This shows the case where nP material is used. First of all
Manufacturing of this example will be explained using the drawings. n+-I
1- on the nP substrate 1 through the n+-InP buffer layer 2
InGaAsP/InPMQW original waveguide layer 3 + p I
The nGaAsP layer was grown by a 4'1 VPE method. 1-I
nGaAsP/InP MQW original waveguide layer 3p-I
The absorption edges of the nGaAsP layer 4 are 1.3 am, respectively.
It is 1.15 μm. Next, p-InGaAsP layer 4
A diffraction grating 5 is formed thereon (by a 2X beam interference exposure method using a He-Cd laser). 1 - InGaAsP/InPMQW original waveguide layer 3t - Optical waveguide 3t used as waveguide layer = 1.35 μm
The effective refractive index ny is 3.4, and the period A of the diffraction grating 5 is approximately 400 to satisfy the second order Bragg condition.
It is set as OA. Next, Au/Zu, which will become the p-type ohmic electrode 6, is formed in a donut shape on the p-InGaAsP layer 4, and the outside of the donut is removed by etching to form a cylindrical meb 7. Finally, an n-type ohmic electrode 8 was formed on the n''-InP substrate 1 except for the part directly under the mesa 7.
次に本実施例の動作について説明する。メサ７の上から
λ＝ １．３２μ慣の元１０ａを入射させると、当初こ
の光に対し、回析格子５はブラッグ条件を満足せず、そ
の′！！ま基板を透過し元１０ｂとして出射される。次
に電極６，８間に逆バイアスを印加すると、ＭＱＷ導波
路層３に電界が印加され、先に述べたようにλ＝１．３
２μｍの元に対し吸収係数が増加し出射光１０ｂが減衰
ｔ−ｈ始すると共に、ＭＱＷの屈折率変化によりブラッ
グ条件が変化し、ある電界に於て入射光１０ａは導波光
１０Ｃに結合され、出射光１０ｂは大きく減少する。つ
まり、平面型の元ゲート素子が実現できる。本実施例は
光の吸収のみを利用しているのではないため元吸収長（
ＭＱＷ層浮）ｔ−大きくとらなくても大きな消光比が可
能である。しかも制御手段は電界でありキャリアの移動
をともなわないため、動作速度は素子容量Ｃと直列抵抗
几で決まる０８時定数を小さくすることにより数ＧＨｚ
以上が容易に得られる。Next, the operation of this embodiment will be explained. When the element 10a with λ = 1.32μ is incident from above the mesa 7, the diffraction grating 5 initially does not satisfy the Bragg condition for this light, and the '! ! The light passes through the substrate and is emitted as a source 10b. Next, when a reverse bias is applied between the electrodes 6 and 8, an electric field is applied to the MQW waveguide layer 3, and as mentioned earlier, λ=1.3
The absorption coefficient increases with respect to the original 2 μm, and the output light 10b begins to attenuate t-h, and the Bragg condition changes due to the change in the refractive index of the MQW, and the incident light 10a is coupled to the guided light 10C in a certain electric field. The output light 10b is greatly reduced. In other words, a planar original gate element can be realized. Since this example does not utilize only light absorption, the original absorption length (
MQW layer floating) A large extinction ratio is possible without increasing t. Moreover, since the control means is an electric field and does not involve movement of carriers, the operating speed can be reduced to several GHz by reducing the time constant determined by the element capacitance C and the series resistance.
The above can be easily obtained.
本実施例では回析格子の周期を一定としているため、ブ
ラッグ条件を満足する成長は非常に狭い帯域を持ってお
り、消光状態を得るには印加電圧をある一定の値に保た
ねばならない。しかし回析格子を謂ゆるチャープ回析格
子とすることＫよシ印加電圧の制御の厳しさは大幅に緩
和される。回析格子の形成は本実施例のように素子の最
上部に形成する他、基板に直接格子を形成しその上に各
層を成長する方法も考えられる。ｎ＋−ＩｎＰ基板１は
光吸収特性を持つため吸収損失の低減のためには基板を
ある程度エッチオフした方が有利である０
以上の実施例ではＩｎＧａＡｓ／ＩｎＰ系材料を例に説
明したが、他の材料系、例えばＧａＡｓ／ＡｌＧａＡｓ
、 Ｉ ｎＧ ａＡ ｓ ／Ｉ ｎＡＩ Ａ ｓ系等
にも適用可能である０
（発明の効果）
以上詳細に説明したように本発明によれば、低電圧で高
消光比がとれ、しかも高速動作が可能な平面型光制御素
子が得られる。In this example, since the period of the diffraction grating is constant, the growth that satisfies the Bragg condition has a very narrow band, and the applied voltage must be kept at a certain value to obtain the extinction state. However, by using a so-called chirped diffraction grating as the diffraction grating, the severity of the control of the applied voltage is greatly reduced. In addition to forming the diffraction grating on the top of the element as in this embodiment, it is also possible to form the grating directly on the substrate and grow each layer thereon. Since the n+-InP substrate 1 has light absorption characteristics, it is advantageous to etch off the substrate to some extent in order to reduce absorption loss.0 In the above embodiments, InGaAs/InP material was used as an example, but other materials may be used. material system, e.g. GaAs/AlGaAs
, InGaAs / InAlAs system, etc.0 (Effects of the Invention) As explained in detail above, according to the present invention, a high extinction ratio can be obtained at low voltage, and high-speed operation can be achieved. A possible planar light control element can be obtained.
第１図は本発明による平面型光制御素子の１実施例を示
す斜視図、第２図、第３図は本発明に用いる多重量子井
戸構造の電界による複素屈折率変化を説明するための特
性図、第４図は従来の平面型光制御素子の構造、動作を
説明するための斜視図である。
１−ｎ”−ＩｎＰ基板、２・・・ｎ”−ＩｎＰｎアバ２
フフ
−ＩｎＧａＡｓＰ層、５・・・回析格子、６・・・ｐ型
オーム性電極、７・・・メサ、８・・・ｎ型オーム性電
極、ｔＯａ。
１０ｂ，１０ｃ・・・光。
代理人 弁理士 内 原 晋
第１図
Ｌ−ｎ” −Ｉ ｎ Ｐ基板
２ − ｎ中−ＩｎＰ／（−ｚ７７層
３−ｉ−ＩｎＧａＡｓＰ ＭＱＷ光−し皮１４・・
・ｐ−ｒｎＧａＡｓＰＮ
Ｓ・・・回折梯子
６・・・Ｐ型オームａ電極
７・・・メサ
８・・・ｎ型オーＡ＋′ｉ＠径
１０ａ，Ｊｏｂ＋ １０ｃ・＝光
第２図
’７８０ ８００ ８２０ ８４０ ８６゜ジ皮長（ｎ
ｍ）−
第３図
第４図FIG. 1 is a perspective view showing one embodiment of a planar light control element according to the present invention, and FIGS. 2 and 3 show characteristics for explaining changes in complex refractive index due to an electric field of a multiple quantum well structure used in the present invention. 4 are perspective views for explaining the structure and operation of a conventional planar light control element. 1-n"-InP substrate, 2...n"-InPn substrate 2
Fufu-InGaAsP layer, 5... Diffraction grating, 6... P-type ohmic electrode, 7... Mesa, 8... N-type ohmic electrode, tOa. 10b, 10c...light. Agent Patent Attorney Susumu UchiharaFigure 1 L-n'' -InP substrate 2-n-InP/(-z77 layer 3-i-InGaAsP MQW light-shield 14...
・p-rnGaAsPN S...Diffraction ladder 6...P-type ohm a electrode 7...Mesa 8...n-type ohm A+'i@diameter 10a, Job+ 10c=light Fig. 2 '780 800 820 840 86° skin length (n
m) - Figure 3 Figure 4
Claims (1)
半導体層よりもバンドギャップの広い第２の半導体層で
はさんだ量子井戸を層厚方向に多重に有する多重量子井
戸構造と回析格子の形成された層とを導波路層、クラッ
ド層の少なくとも１部に含む半導体光導波路と、前記多
重量子井戸構造に電界を印加する手段と、前記光導波路
の回析格子が形成された部分に各層に略垂直に光を導く
手段とから成ることを特徴とする平面型光制御素子。A multi-quantum well structure having multiple quantum wells in the layer thickness direction, in which a first semiconductor layer having a thickness of about the de Broglie wavelength is sandwiched between a second semiconductor layer having a wider band gap than the first semiconductor layer, and a diffraction grating. a semiconductor optical waveguide including the formed layer in at least part of a waveguide layer or cladding layer; a means for applying an electric field to the multi-quantum well structure; and means for guiding light substantially perpendicularly to the planar light control element.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP61156404A JPH0656456B2 (en) | 1986-07-02 | 1986-07-02 | Planar light control element |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP61156404A JPH0656456B2 (en) | 1986-07-02 | 1986-07-02 | Planar light control element |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JPS6310125A true JPS6310125A (en) | 1988-01-16 |
| JPH0656456B2 JPH0656456B2 (en) | 1994-07-27 |
Family
ID=15627001
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP61156404A Expired - Lifetime JPH0656456B2 (en) | 1986-07-02 | 1986-07-02 | Planar light control element |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JPH0656456B2 (en) |
Cited By (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPH01204018A (en) * | 1988-02-10 | 1989-08-16 | Nec Corp | Optical modulator |
| JPH024209A (en) * | 1988-06-21 | 1990-01-09 | Matsushita Electric Ind Co Ltd | Waveguide and photodetector |
| JPH02154221A (en) * | 1988-12-06 | 1990-06-13 | Fujitsu Ltd | Optical semiconductor device |
| JPH04131601U (en) * | 1991-05-24 | 1992-12-03 | 積水樹脂株式会社 | insect repellent sheet |
| FR2741489A1 (en) * | 1995-11-21 | 1997-05-23 | Thomson Csf | Quantum well electromagnetic waves modulator especially inter-sub-band quantum wells |
Citations (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS50104036A (en) * | 1974-01-14 | 1975-08-16 | ||
| JPS57142608A (en) * | 1981-02-27 | 1982-09-03 | Canon Inc | Optical coupler |
| JPS59116612A (en) * | 1982-12-23 | 1984-07-05 | Toshiba Corp | Light modulator |
-
1986
- 1986-07-02 JP JP61156404A patent/JPH0656456B2/en not_active Expired - Lifetime
Patent Citations (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS50104036A (en) * | 1974-01-14 | 1975-08-16 | ||
| JPS57142608A (en) * | 1981-02-27 | 1982-09-03 | Canon Inc | Optical coupler |
| JPS59116612A (en) * | 1982-12-23 | 1984-07-05 | Toshiba Corp | Light modulator |
Cited By (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPH01204018A (en) * | 1988-02-10 | 1989-08-16 | Nec Corp | Optical modulator |
| JPH024209A (en) * | 1988-06-21 | 1990-01-09 | Matsushita Electric Ind Co Ltd | Waveguide and photodetector |
| JPH02154221A (en) * | 1988-12-06 | 1990-06-13 | Fujitsu Ltd | Optical semiconductor device |
| JPH04131601U (en) * | 1991-05-24 | 1992-12-03 | 積水樹脂株式会社 | insect repellent sheet |
| FR2741489A1 (en) * | 1995-11-21 | 1997-05-23 | Thomson Csf | Quantum well electromagnetic waves modulator especially inter-sub-band quantum wells |
Also Published As
| Publication number | Publication date |
|---|---|
| JPH0656456B2 (en) | 1994-07-27 |
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