JPH0719005B2 - Optical bistable element - Google Patents
Optical bistable elementInfo
- Publication number
- JPH0719005B2 JPH0719005B2 JP59142326A JP14232684A JPH0719005B2 JP H0719005 B2 JPH0719005 B2 JP H0719005B2 JP 59142326 A JP59142326 A JP 59142326A JP 14232684 A JP14232684 A JP 14232684A JP H0719005 B2 JPH0719005 B2 JP H0719005B2
- Authority
- JP
- Japan
- Prior art keywords
- optical bistable
- light
- etalon
- optical
- amount
- 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.)
- Expired - Lifetime
Links
Description
【発明の詳細な説明】 〔発明の利用分野〕 本発明は光計算機等の論理回路や記憶回路を構成できる
光双安定素子に係り、特に製造が容易で性能の良い光双
安定素子に関する。Description: BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an optical bistable element capable of forming a logic circuit or a storage circuit of an optical computer or the like, and more particularly to an optical bistable element which is easy to manufacture and has good performance.
〔発明の背景〕 これまで光双安定素子としてはGaAs単結晶のエタロンを
用いたもの（H.M.Gibbs et.al.,“Optical bistability
in semiconductors"Appl.Phys.Lett.35（６）,15,Sep
t.1979,p451〜453参照）、あるいはInSb単結晶エタロン
を用いたもの（D.A.B.Miller et.al.“Two beam optica
l signal amplification and bistability in InSb".Op
tics Communications Vol.31,No.1,Oct.,1979,p101〜10
4参照）が報告されている。しかし、これらの光双安定
素子は120゜Kの低温でしか動作しなかつた。その後、GaA
sとAlAsによる超格子を用いた光双安定素子が室温で動
作した（H.M.Gibbs et.al,“Room temperature exciton
ic optical bistability in a GaAs−GaAlAs superlatt
ice etalon"Appl.Phys.Lett.,41（３）,I Aug.1982,p22
1〜222参照）。このような室温における動作は、超格子
構造にすることにより励起子の結合エネルギーが増加
し、その結果励起子が安定に存在することによる。励起
子の存在は屈折率の増加をもたらす。第１図に示すよう
に基板１の上に形成されたエタロン２に第２図に示すよ
うに光を入射すると、入射光３と反射光３′がエタロン
２の内部で干渉する。エタロン２の厚さを入射光の波長
の整数倍にしておくと、入射光３と反射光３′のピーク
が重なりエタロン内部の光量は増加する。このとき入射
光３の量が少ない場合は励起子の量は少なく、したがつ
て屈折率も大きくならない。その結果、入射光３の大部
分はエタロン２を通過して、出射するが、その出射光４
の光量は当然少ない。BACKGROUND OF THE INVENTION Optical bistable devices that have used etalon of GaAs single crystal (HMGibbs et.al., “Optical bistability”).
in semiconductors "Appl.Phys.Lett.35 (6), 15, Sep
t.1979, p451-453) or using an InSb single crystal etalon (DAB Miller et.al. “Two beam optica”).
l signal amplification and bistability in InSb ".Op
tics Communications Vol.31, No.1, Oct., 1979, p101〜10
4) has been reported. However, these optical bistable elements can only operate at a low temperature of 120 ° K. Then GaA
An optical bistable device using a superlattice composed of s and AlAs operated at room temperature (HMGibbs et.al, “Room temperature exciton
ic optical bistability in a GaAs−GaAlAs superlatt
ice etalon "Appl.Phys.Lett., 41 (3), I Aug.1982, p22
See 1-222). Such operation at room temperature is due to the fact that the superlattice structure increases the binding energy of excitons, and as a result, the excitons are stably present. The presence of excitons results in an increase in refractive index. When light is incident on the etalon 2 formed on the substrate 1 as shown in FIG. 1 as shown in FIG. 2, the incident light 3 and the reflected light 3 ′ interfere inside the etalon 2. When the thickness of the etalon 2 is set to an integral multiple of the wavelength of the incident light, the peaks of the incident light 3 and the reflected light 3'are overlapped with each other, and the light amount inside the etalon increases. At this time, when the amount of incident light 3 is small, the amount of excitons is small, and thus the refractive index does not increase. As a result, most of the incident light 3 passes through the etalon 2 and is emitted, but the emitted light 4
The amount of light is naturally low.
入射光の量が多い場合には励起子が多く励起されるため
屈折率が増加する。その結果、反射光３′の量も増加
し、それが入射光３と干渉して重なり、ますますエタロ
ン内の光量は増加する。したがつて励起子の量もますま
す増加し、屈折率も増加してエタロン内の光量は更に増
加する。すなわち入射光の量は一定でもエタロン内の光
量は入射時より増加する。この光の一部はエタロンの外
に出射するが、その光量は入射光量が少ない場合に較べ
てはるかに大きい。また、この状態では入射光を減少さ
せてもエタロン内の光量の減少は少なく、入射光３と出
射光３′の関係は第３図に示すごとく、いわゆる双安定
性を示す。この特性が論理機能や記憶機能と関連するこ
とはここで述べるまでもない。When the amount of incident light is large, many excitons are excited and the refractive index increases. As a result, the amount of reflected light 3'also increases, which interferes with the incident light 3 and overlaps with it, so that the amount of light in the etalon further increases. Therefore, the amount of excitons also increases, the refractive index also increases, and the amount of light in the etalon further increases. That is, even if the amount of incident light is constant, the amount of light in the etalon increases from the time of incidence. A part of this light goes out of the etalon, but the amount of light is much larger than that when the amount of incident light is small. Further, in this state, even if the incident light is reduced, the amount of light in the etalon does not decrease so much, and the relationship between the incident light 3 and the emitted light 3'shows so-called bistability as shown in FIG. It goes without saying that this property is related to the logical function and the memory function.
前述のようにGaAsとAlAsによる超格子が室温において光
双安定性を示したが、超格子は製造方法が複雑で、かつ
高度の技術を要するという欠点があり、その実用化は極
めて難かしいと云える。As mentioned above, the superlattice of GaAs and AlAs showed optical bistability at room temperature, but the superlattice has the drawbacks that the manufacturing method is complicated and requires high technology, and its practical application is extremely difficult. Can say
本発明の目的は、室温で動作し、かつ構造が簡単で製造
が容易な光双安定素子を提供することにある。An object of the present invention is to provide an optical bistable device that operates at room temperature, has a simple structure, and is easy to manufacture.
本発明者は、励起子の結合エネルギー（束縛エネルギー
と呼ばれることもある）が大きいと想定され、かつ構造
が簡単な物質について光双安定性の研究を行つた結果、
HgI2，PbI2あるいはGaSeの薄膜結晶で構成されたエタロ
ンが安定な光双安定性を有することを見出した。これら
の物質の結晶構造は層状構造で、層間が弱いVan der wa
als力で結合している。このような物質は物理学的考察
から励起子の結合エネルギーが大きいと判断した。また
このような物質の薄膜結晶の蒸着法などの簡単な方法で
製作でき、かつ基板の結晶性にもよらないことがわかつ
た。The present inventor performed optical bistability research on a substance whose binding energy of excitons (sometimes called binding energy) is supposed to be large and which has a simple structure.
We have found that an etalon composed of HgI 2 , PbI 2 or GaSe thin film crystals has stable optical bistability. The crystal structure of these substances is a layered structure, and the van der wa
They are bound by als power. It was determined from physical considerations that such a substance has a large exciton binding energy. Further, it has been found that it can be manufactured by a simple method such as a vapor deposition method of a thin film crystal of such a substance and does not depend on the crystallinity of the substrate.
さらにこの薄膜結晶は基板面の垂直な方向がｃ軸となる
ように成長，形成されるので極めて使い易い光双安定素
子ができる。Furthermore, since this thin film crystal is grown and formed so that the direction perpendicular to the substrate surface becomes the c-axis, an optical bistable device that is extremely easy to use can be made.
第４図に本発明の光双安定素子の構造を示す。FIG. 4 shows the structure of the optical bistable element of the present invention.
基板１は光双安定素子の動作に必要な波長の光を透過す
る物質で、一例としてガラスがある。The substrate 1 is a substance that transmits light having a wavelength necessary for the operation of the optical bistable element, and glass is an example.
基板１の上にHgI2，PbI2,GaSeなどの励起子の結合エネ
ルギーの大きい物質（以下励起子物質と記す）の薄膜結
晶12を形成する。第５図に示すように薄膜結晶12のｃ軸
22は基板１の面と垂直になり、この方向に光を入射した
時に光双安定特性が得られた。すなわち第６図に示すよ
うに光双安定素子21にほぼ垂直に入射光３を入射すると
入射光３と出射光４の間に第３図に示した光双安定特性
が得られた。On the substrate 1, a thin film crystal 12 of a substance such as HgI 2 , PbI 2 , GaSe or the like having a large exciton binding energy (hereinafter referred to as exciton substance) is formed. As shown in Fig. 5, the c-axis of the thin film crystal 12
22 is perpendicular to the surface of the substrate 1, and optical bistable characteristics were obtained when light was incident in this direction. That is, as shown in FIG. 6, when the incident light 3 is incident on the optical bistable element 21 substantially perpendicularly, the optical bistable characteristic shown in FIG. 3 is obtained between the incident light 3 and the outgoing light 4.
第７図に示すように励起子物質の薄膜結晶12の両面に反
射率の大きい物質の薄膜５を付着すると、より少ない光
量で光双安定特性が実現した。As shown in FIG. 7, when the thin film 5 made of a substance having a high reflectance was attached to both surfaces of the thin film crystal 12 made of an exciton substance, the optical bistable characteristic was realized with a smaller amount of light.
以下、本発明の一実施例を第８図により説明する。 An embodiment of the present invention will be described below with reference to FIG.
純度99.999％のHgI2を真空蒸着装置のボート６に入れ、
電源８によりボート支持電極７を介してボート６を800
℃に加熱してシリカガラス基板11上に薄膜結晶12を形成
し、光双安定素子を製作した。薄膜結晶12の厚さは2.65
μｍとした。この薄膜結晶に基板11側から波長530nmの
レーザ光（N2光励起色素レーザ光）をスポツト径５μｍ
で入射した。次に入射光の強度と出射光の関係を室温
（20℃）にて測定したところ、第９図のように双安定特
性を示した。Put 99.999% pure HgI 2 in the boat 6 of the vacuum evaporation system,
800 boats 6 via the boat support electrode 7 by the power supply 8
The thin film crystal 12 was formed on the silica glass substrate 11 by heating to ℃, and an optical bistable element was manufactured. The thickness of the thin film crystal 12 is 2.65.
μm. A laser beam with a wavelength of 530 nm (N 2 photoexcited dye laser beam) was spotted on this thin film crystal from the substrate 11 side with a spot diameter of 5 μm.
It was incident at. Next, when the relationship between the intensity of the incident light and the emitted light was measured at room temperature (20 ° C.), it showed a bistable characteristic as shown in FIG.
HgI2の代りに、PbI2またはGaSeの薄膜結晶を形成させた
素子によつても同様の光双安定特性が示された。Instead of HgI 2, similar optical bistable characteristics even One by the element to form a thin-film crystal of PbI 2 or GaSe was shown.
本発明によれば、構造が極めて簡単で製造が容易な、か
つ室温で動作する光双安定素子が製作できるので、実用
的効果が大きい。According to the present invention, an optical bistable element that has an extremely simple structure and is easy to manufacture and that operates at room temperature can be manufactured, and therefore, the practical effect is large.
第１図はエタロンの構成図、第２図は光双安定特性を説
明する図、第３図は光双安定特性の展形図、第４図は本
発明の構成図、第５図は薄膜結晶のｃ軸を示す図、第６
図は入射光および出射光を示す図、第７図は本発明の一
実施態様図、第８図は実施例を説明する図、第９図は実
施例の光双安定特性を示す図、である。 １…基板、２…エタロン、３…入射光、３′…反射光、
４…出射光、５…反射膜、６…ボート、７…ボート支持
電極、８…電源、11…シリカガラス基板、12…励起子物
質の薄膜結晶、21…光双安定素子、22…薄膜結晶のｃ
軸。FIG. 1 is a block diagram of an etalon, FIG. 2 is a diagram for explaining the optical bistable characteristic, FIG. 3 is a developed diagram of the optical bistable characteristic, FIG. 4 is a structural diagram of the present invention, and FIG. 5 is a thin film. Diagram showing c-axis of crystal, 6th
FIG. 7 is a diagram showing incident light and emitted light, FIG. 7 is a diagram showing an embodiment of the present invention, FIG. 8 is a diagram illustrating an example, and FIG. 9 is a diagram showing optical bistable characteristics of the example. is there. 1 ... Substrate, 2 ... Etalon, 3 ... Incident light, 3 '... Reflected light,
4 ... Emitted light, 5 ... Reflective film, 6 ... Boat, 7 ... Boat support electrode, 8 ... Power supply, 11 ... Silica glass substrate, 12 ... Excitonic material thin film crystal, 21 ... Optical bistable element, 22 ... Thin film crystal C
axis.
Claims (3)
のうちのいずれかをその励起子吸収波長を透過する基板
上に膜厚が前記励起子吸収波長のほぼ整数倍となるよう
に膜形成をしたことを特徴とする光双安定素子。1. Excitonic absorption of HgI 2 , PbI 2 or GaSe
An optical bistable device, characterized in that any one of the above is formed on a substrate which transmits the exciton absorption wavelength so that the film thickness is approximately an integral multiple of the exciton absorption wavelength.
特許請求の範囲第１項記載の光双安定素子。2. The optical bistable element according to claim 1, wherein the substrate is made of glass.
徴とする特許請求の範囲第１項記載の光双安定素子。3. The optical bistable element according to claim 1, wherein the film formation is performed by a vapor deposition method.
Priority Applications (2)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP59142326A JPH0719005B2 (en) | 1984-07-11 | 1984-07-11 | Optical bistable element |
| EP19850304850 EP0171192A1 (en) | 1984-07-11 | 1985-07-08 | Optical bistable device |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP59142326A JPH0719005B2 (en) | 1984-07-11 | 1984-07-11 | Optical bistable element |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JPS6122328A JPS6122328A (en) | 1986-01-30 |
| JPH0719005B2 true JPH0719005B2 (en) | 1995-03-06 |
Family
ID=15312739
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP59142326A Expired - Lifetime JPH0719005B2 (en) | 1984-07-11 | 1984-07-11 | Optical bistable element |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JPH0719005B2 (en) |
Families Citing this family (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS62219728A (en) * | 1986-03-20 | 1987-09-28 | Hitachi Ltd | Method and apparatus for selecting optical signal channel |
Citations (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS5936988A (en) * | 1982-08-26 | 1984-02-29 | Agency Of Ind Science & Technol | Vertical oscillation type semiconductor laser |
-
1984
- 1984-07-11 JP JP59142326A patent/JPH0719005B2/en not_active Expired - Lifetime
Patent Citations (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS5936988A (en) * | 1982-08-26 | 1984-02-29 | Agency Of Ind Science & Technol | Vertical oscillation type semiconductor laser |
Also Published As
| Publication number | Publication date |
|---|---|
| JPS6122328A (en) | 1986-01-30 |
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