JPH03202810A - Optical waveguide device and production thereof - Google Patents
Optical waveguide device and production thereofInfo
- Publication number
- JPH03202810A JPH03202810A JP1340430A JP34043089A JPH03202810A JP H03202810 A JPH03202810 A JP H03202810A JP 1340430 A JP1340430 A JP 1340430A JP 34043089 A JP34043089 A JP 34043089A JP H03202810 A JPH03202810 A JP H03202810A
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- Prior art keywords
- optical waveguide
- substrate
- optical
- side end
- control electrode
- Prior art date
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Links
- 230000003287 optical effect Effects 0.000 title claims abstract description 102
- 238000004519 manufacturing process Methods 0.000 title claims description 8
- 239000000758 substrate Substances 0.000 claims abstract description 38
- 238000000034 method Methods 0.000 claims description 9
- 238000005520 cutting process Methods 0.000 claims description 4
- 230000005684 electric field Effects 0.000 abstract description 8
- 238000009826 distribution Methods 0.000 abstract description 7
- 239000004065 semiconductor Substances 0.000 abstract description 3
- 230000008033 biological extinction Effects 0.000 abstract description 2
- 239000011248 coating agent Substances 0.000 abstract description 2
- 238000000576 coating method Methods 0.000 abstract description 2
- 239000010408 film Substances 0.000 description 27
- 230000000694 effects Effects 0.000 description 26
- 239000013078 crystal Substances 0.000 description 6
- 238000004891 communication Methods 0.000 description 4
- 238000010586 diagram Methods 0.000 description 3
- 239000002184 metal Substances 0.000 description 3
- 238000007747 plating Methods 0.000 description 3
- 238000007740 vapor deposition Methods 0.000 description 3
- 235000017166 Bambusa arundinacea Nutrition 0.000 description 1
- 235000017491 Bambusa tulda Nutrition 0.000 description 1
- 241001164374 Calyx Species 0.000 description 1
- 229910003327 LiNbO3 Inorganic materials 0.000 description 1
- 244000082204 Phyllostachys viridis Species 0.000 description 1
- 235000015334 Phyllostachys viridis Nutrition 0.000 description 1
- 244000007853 Sarothamnus scoparius Species 0.000 description 1
- 239000011425 bamboo Substances 0.000 description 1
- 230000005540 biological transmission Effects 0.000 description 1
- 230000015572 biosynthetic process Effects 0.000 description 1
- 238000007796 conventional method Methods 0.000 description 1
- 238000000151 deposition Methods 0.000 description 1
- 230000006866 deterioration Effects 0.000 description 1
- 229910003460 diamond Inorganic materials 0.000 description 1
- 239000010432 diamond Substances 0.000 description 1
- 238000005516 engineering process Methods 0.000 description 1
- 238000005530 etching Methods 0.000 description 1
- 230000031700 light absorption Effects 0.000 description 1
- 239000000463 material Substances 0.000 description 1
- 239000012528 membrane Substances 0.000 description 1
- 238000001259 photo etching Methods 0.000 description 1
- 230000010287 polarization Effects 0.000 description 1
- 230000000087 stabilizing effect Effects 0.000 description 1
- 230000002123 temporal effect Effects 0.000 description 1
- 239000010409 thin film Substances 0.000 description 1
Classifications
-
- G—PHYSICS
- G02—OPTICS
- G02F—OPTICAL 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
- G02F2203/00—Function characteristic
- G02F2203/21—Thermal instability, i.e. DC drift, of an optical modulator; Arrangements or methods for the reduction thereof
Landscapes
- Optical Integrated Circuits (AREA)
Abstract
Description
【発明の詳細な説明】
〔概要〕
光導波路デバイスとその製造方法に関し、高速・高安定
動作を求められる光導波路デノ\イス、たとえば、外部
光変調器において、周囲温度の変化による動作点の変動
などを防止することを目的とし、
電気光学効果と焦電効果を有する基板の一方の主面上に
、第1および第2の分岐光導波路を有する光導波路を設
け、前記分岐光導波路の上方に第1の制御電極および第
2の制御電極を配設してなる光導波路デバイスにおいて
、前記基板の2つの主面のうちの少なくとも前記制御電
極が配設された一方の主面と、前記基板の2つの側端面
のうちの少なくとも入力信号用の第1の制御電極に近接
した一方の側端面とに半導電性膜を形成して光導波路デ
バイスを構成する。そして、前記光導波路デバイスは電
気光学効果と焦電効果を有する基板用ウェーハに光導波
路を形成する工程と、前記ウェーハ上にバッファ層を形
成する工程と、第1の分岐光導波路に近接してウェーハ
に溝を形成する工程と、バッファ層の上と溝の内側面に
半導電性膜を形成する工程と、分岐光導波路の上方に前
記バッファ層と半導電性膜を介して第1および第2の制
御電極を形成する工程と、前記溝の部分でウェーハを切
断して光導波路デバイスチップを形成する工程とから製
造することができる。[Detailed Description of the Invention] [Summary] Regarding optical waveguide devices and their manufacturing methods, in optical waveguide devices that require high-speed and highly stable operation, such as external optical modulators, it is possible to change the operating point due to changes in ambient temperature. For the purpose of preventing fluctuations, etc., an optical waveguide having first and second branched optical waveguides is provided on one main surface of a substrate having an electro-optic effect and a pyroelectric effect, and an optical waveguide having a first and second branched optical waveguide is provided above the branched optical waveguide. In an optical waveguide device in which a first control electrode and a second control electrode are disposed on at least one of the two principal surfaces of the substrate, at least one principal surface on which the control electrode is disposed; An optical waveguide device is constructed by forming a semiconductive film on at least one of the two side end faces near the first control electrode for input signals. The optical waveguide device includes a step of forming an optical waveguide on a substrate wafer having an electro-optic effect and a pyroelectric effect, a step of forming a buffer layer on the wafer, and a step of forming an optical waveguide in the vicinity of the first branched optical waveguide. forming a groove in the wafer; forming a semiconductive film on the buffer layer and on the inner surface of the groove; The optical waveguide device chip can be manufactured by forming the second control electrode, and cutting the wafer at the groove portion to form an optical waveguide device chip.
本発明は、高速・高安定な光導波路デバイス。 The present invention provides a high-speed and highly stable optical waveguide device.
とくに、電気光学結晶を基板とした外部光変調器の温度
特性の改善に関する。In particular, it relates to improving the temperature characteristics of external optical modulators using electro-optic crystals as substrates.
最近の光通信システムの光送信系において、たとえば、
1.6GHz程度までの光通信システムにおいては、レ
ーザダイオード(L D)を直接変調する方式を用いて
きたが、変調周波数がより高くなると変調光波長の時間
的微小変動、いわゆる、波長チャーピング現象が起こり
高速化と長距離通信への限界となる。In the optical transmission system of recent optical communication systems, for example,
In optical communication systems up to about 1.6 GHz, a method of directly modulating a laser diode (LD) has been used, but as the modulation frequency becomes higher, small temporal fluctuations in the modulated light wavelength, the so-called wavelength chirping phenomenon, occur. This is the limit for high-speed and long-distance communication.
一方、今後ますます大容量・長距離通信の要求が強まっ
てくるので、より高速、かつ、温度安定性の高い光導波
路デバイス、たとえば、外部光変調器の開発が求められ
ている。On the other hand, as the demand for large-capacity and long-distance communication will become stronger in the future, there is a need to develop optical waveguide devices that are faster and have higher temperature stability, such as external optical modulators.
高速光変調方式としては、半導体レーザ光を外部で変調
する外部変調方式、とくに、電気光学結晶基板上に分岐
光導波路を設け、進行波電極で駆動するマツハツエンダ
型光変調器が知られている。As a high-speed optical modulation method, an external modulation method in which a semiconductor laser beam is externally modulated is known, and in particular, a Matsuhatsu Enda type optical modulator in which a branched optical waveguide is provided on an electro-optic crystal substrate and is driven by a traveling wave electrode is known.
第8図は光変調器の基本構成例を示す図で、同図(イ)
は平面図、同図(ロ)はY−Y’断面図である。Figure 8 is a diagram showing an example of the basic configuration of an optical modulator.
is a plan view, and the same figure (b) is a YY' sectional view.
図中、1は平面に加工した電気光学効果を有する基板、
たとえば、LiNbO3基板である。2は光導波路で中
間に分岐光導波路2a、 2bが形成されている。この
光導波路は通常基板の表面にTiなどの金属を、光導波
路部分だけに選択的に拡散させ、その部分の屈折率を回
りの部分よりも少し大きくなるようにしである)3は第
1の制御電極で、たとえば、進行波信号電極、4は第2
の制御電極、たとえば、接地電極である。5は光導波路
上の金属電極層への光の吸収を小さくするためのバッフ
ァ崩て、通常、SiO□などの薄膜が用いられている。In the figure, 1 is a substrate having an electro-optic effect processed into a flat surface;
For example, a LiNbO3 substrate. 2 is an optical waveguide, and branched optical waveguides 2a and 2b are formed in the middle. This optical waveguide is usually made by selectively diffusing metal such as Ti on the surface of the substrate only to the optical waveguide part, so that the refractive index of that part is slightly larger than that of the surrounding parts) 3 is the first A control electrode, for example a traveling wave signal electrode, 4 is a second
control electrode, for example a ground electrode. Reference numeral 5 denotes a buffer layer for reducing the absorption of light into the metal electrode layer on the optical waveguide, and a thin film such as SiO□ is usually used.
第1の制御電極3と第2の制御電極4はバッファ層5を
介して光導波路上に、Auなどの金属を蒸着あるいはメ
ツキによって形成している。The first control electrode 3 and the second control electrode 4 are formed on the optical waveguide via the buffer layer 5 by vapor deposition or plating of a metal such as Au.
いま、たとえば、こ\には図示してない半導体レーザか
ら発した直流光が左側の光導波路2から入り、分岐光導
波路2a、 2bで2つに分けられ、その間に、第1の
制御電極3に高周波変調信号源8から信号電圧を印加す
ると、基板上に設けられた前記分岐光導波路2a、 2
bにおける電気光学効果によって分岐された両光に位相
差が生じる。この両光を再び合流させて、右側の一本の
光導波路2から変調された光信号出力を取り出し、二\
に図示してない光検知器で電気信号に変換するように構
成されている。前記分岐光導波路2a、 2bにおける
両光の位相差が0.あるいは、πになるように駆動電圧
を印加すれば、たとえば、光信号出力はON−OFFの
パルス信号として得られる。なお、RTは終端抵抗であ
る。Now, for example, DC light emitted from a semiconductor laser (not shown) enters from the optical waveguide 2 on the left side and is divided into two by the branching optical waveguides 2a and 2b. When a signal voltage is applied from the high frequency modulation signal source 8 to the branch optical waveguides 2a and 2 provided on the substrate,
A phase difference occurs between the two branched lights due to the electro-optic effect at b. These two lights are combined again and the modulated optical signal output is taken out from the single optical waveguide 2 on the right side.
It is configured to convert the signal into an electrical signal using a photodetector (not shown). The phase difference between both lights in the branched optical waveguides 2a and 2b is 0. Alternatively, if a driving voltage is applied so as to be π, the optical signal output can be obtained as an ON-OFF pulse signal, for example. Note that RT is a terminating resistor.
第9図は温度変化による焦電効果を示す断面図である。FIG. 9 is a cross-sectional view showing the pyroelectric effect due to temperature change.
通常、基板lには電気光学効果の大きい酸化物単結晶L
iNb0.、あるいは、LiTaO5の2カツト板が用
いられている。これらの単結晶はいずれも菱面体晶系に
属し比較的大きな焦電効果を有することが知られている
。したがって、基板温度の上昇、あるいは、下降にとも
なって、たとえば、図示したごとき分極を生じ、基板の
両面には正負の電荷か発生するが、バッファ層5を介し
て金属膜からなる第1および第2の制御電極3,4があ
るために基板l中の電界分布が乱され、その結果第1お
よび第2の分岐光導波路(2a’、2b)の屈折率が異
なること\なる。このことは、光変調器で言えば温度変
化にともなって動作点がシフトするということであり、
光変調器の不安定動作を招くことになる。Usually, the substrate L is made of an oxide single crystal L, which has a large electro-optic effect.
iNb0. Alternatively, a two-cut plate of LiTaO5 is used. All of these single crystals belong to the rhombohedral crystal system and are known to have a relatively large pyroelectric effect. Therefore, as the substrate temperature rises or falls, polarization as shown in the figure occurs, and positive and negative charges are generated on both sides of the substrate. Due to the presence of the two control electrodes 3 and 4, the electric field distribution in the substrate l is disturbed, and as a result, the refractive indexes of the first and second branched optical waveguides (2a', 2b) are different. In terms of optical modulators, this means that the operating point shifts as the temperature changes.
This will lead to unstable operation of the optical modulator.
このような焦電効果による不安定性を改善する方法がす
でに提案されており、たとえば、第5図は従来の焦電効
果の影響を防止する例を示す断面図である。すなわち、
バッファ層5の上に動作電圧特性に影響を及ぼさない程
度の比較的高抵抗の半導電性膜6c、たとえば、Si膜
を形成しである。A method for improving instability caused by such a pyroelectric effect has already been proposed. For example, FIG. 5 is a cross-sectional view showing an example of conventional methods for preventing the influence of the pyroelectric effect. That is,
A semiconductive film 6c, for example, a Si film, having a relatively high resistance that does not affect the operating voltage characteristics is formed on the buffer layer 5.
これによって、図示したごとく基板1の中の電界分布は
一様となり、したがって、第1および第2の分岐光導波
路(2a、 2b)に屈折率の差が生じることはなく、
温度変化があっても光変調器の動作点がシフトせず、極
めて安定な光変調器が得られる。As a result, as shown in the figure, the electric field distribution inside the substrate 1 becomes uniform, and therefore, no difference in refractive index occurs between the first and second branched optical waveguides (2a, 2b).
Even if there is a temperature change, the operating point of the optical modulator does not shift, and an extremely stable optical modulator can be obtained.
第7図は焦電効果にもとづく動作点シフトを示す図で、
縦軸に動作点シフトを、横軸に温度をとっである。図中
、■の点線は前記第8図、第9図で説明した基本構成例
の場合で、温度変化に対して極めて不安定な動作を示す
ことがわかる。一方、■の破線は前記第5図で説明した
半導電性膜6cを設けた従来例のデータで広い範囲にわ
たって極めて安定な動作をすることがわかる。Figure 7 is a diagram showing the operating point shift based on the pyroelectric effect.
The vertical axis shows the operating point shift, and the horizontal axis shows temperature. In the figure, the dotted line (■) indicates the case of the basic configuration example explained in FIGS. 8 and 9, and it can be seen that the operation is extremely unstable with respect to temperature changes. On the other hand, the broken line (■) shows the data of the conventional example in which the semiconductive film 6c described in FIG.
しかし、最近は光変調器素子の小形化の要求が強く、ま
た、その巾方向の寸法をできるだけ小さくすることによ
って、同一基板からとれる光変調器チップの数量を増や
して光変調器の価格低減を図るために、進行波信号電極
である第1の制御電極3に近接したぎりぎりのところま
でカントするようになってきた。However, recently there has been a strong demand for miniaturization of optical modulator elements, and by reducing the width dimension as much as possible, the number of optical modulator chips that can be made from the same substrate can be increased and the cost of optical modulators can be reduced. In order to achieve this goal, it has come to be canted as close as possible to the first control electrode 3, which is a traveling wave signal electrode.
第6図は基板中を狭くした光変調器素子と電界分布を示
す断面図である。すなわち、第1の制御電極3のエツジ
と基板1の側端部との間隔d1は。FIG. 6 is a cross-sectional view showing an optical modulator element with a narrow substrate and electric field distribution. That is, the distance d1 between the edge of the first control electrode 3 and the side edge of the substrate 1 is as follows.
たとえば、0.1mm以下であり、第5図の場合のdo
が、たとえば2mm以上であるのに比較してl/20以
下と極めて小さな値になっている。For example, if it is 0.1 mm or less, the do
is, for example, 2 mm or more, but it is an extremely small value of 1/20 or less.
しかし、上記第6図に示したように第1の制御電極3の
エツジと基板1の側端部との間隔d1が極めて小さくな
ってくると、図示したようにそのエツジ部分で電界分布
が乱れ、その結果、第1および第2の分岐光導波路2a
、 2bの屈折率が異なることになり、その屈折率差は
温度変化にともなって変動し、光変調器の不安定動作を
招くことになる。However, as shown in FIG. 6 above, when the distance d1 between the edge of the first control electrode 3 and the side edge of the substrate 1 becomes extremely small, the electric field distribution becomes disordered at the edge as shown in the figure. , As a result, the first and second branch optical waveguides 2a
, 2b will be different, and the difference in refractive index will fluctuate with temperature changes, leading to unstable operation of the optical modulator.
第7図の■の一点鎖線はその動作点シフトの例を示した
もので、lOoCから50°Cの範囲で約1.5vのシ
フトがあり、このま\では実用的に使用することができ
ないという問題があり、その解決が必要であった。The dash-dotted line (■) in Figure 7 shows an example of the operating point shift, and there is a shift of about 1.5 V in the range from 10oC to 50°C, and it cannot be used practically at this point. There was a problem that needed to be solved.
上記の課題は、電気光学効果と焦電効果を有する基板1
の一方の主面上に、第1および第2の分岐光導波路2a
、 2bを有する光導波路2を設け、前記分岐光導波路
2a、 2bの上方に第1の制御電極3および第2の制
御電極4を配設してなる光導波路デバイスにおいて、前
記基板1の2つの主面のうちの少なくとも前記制御電極
3および4が配設された一方の主面と、前記基板1の2
つの側端面のうちの少なくとも入力信号用の第1の制御
電極3に近接した一方の側端面とに半導電性膜6を形成
した光導波路デバイスにより解決することができる。The above problem is a substrate 1 having an electro-optic effect and a pyroelectric effect.
on one main surface of the first and second branch optical waveguides 2a.
, 2b, and a first control electrode 3 and a second control electrode 4 are arranged above the branched optical waveguides 2a and 2b. At least one of the main surfaces on which the control electrodes 3 and 4 are disposed, and 2 of the substrate 1
This problem can be solved by an optical waveguide device in which a semiconductive film 6 is formed on at least one of the two side end faces that is close to the first control electrode 3 for input signals.
そして、前記光導波路デバイスは電気光学効果と焦電効
果を有する基板用ウェーハ10に第1および第2の分岐
光導波路2a、 2bを有する光導波路2を形成する工
程と、前記ウェーハIO上にバッファ層5を形成する工
程と、前記第1の分岐光導波路2aに近接して前記ウェ
ーハ10に溝7を形成する工程と、前記ウェーハlOに
形成されたバッファ層5の上と前記溝7の内側面に半導
電性膜6を形成する工程と、前記分岐光導波路2a、
2bの上方に前記バッファ層5と半導電性膜6を介して
第1および第2の制御電極3.4を形成する工程と、前
記溝7の部分で前記ウェーハ10を切断して光導波路デ
バイスチップを形成する工程とを少なくとも含む方法に
より製造することができる。The optical waveguide device includes a step of forming an optical waveguide 2 having first and second branched optical waveguides 2a and 2b on a substrate wafer 10 having an electro-optic effect and a pyroelectric effect, and a step of forming a buffer on the wafer IO. a step of forming a layer 5, a step of forming a groove 7 in the wafer 10 close to the first branched optical waveguide 2a, and a step of forming a groove 7 on the buffer layer 5 formed on the wafer IO and inside the groove 7. a step of forming a semiconductive film 6 on the side surface, and the branched optical waveguide 2a;
forming first and second control electrodes 3.4 above the buffer layer 5 and the semiconductive film 6, and cutting the wafer 10 at the groove 7 to form an optical waveguide device. It can be manufactured by a method including at least a step of forming a chip.
本発明の構成によれば、光導波路デバイスの巾が細い場
合でも、基板1の主面だけでなくその側端部まで連続し
て高抵抗の半導電性膜6で覆っであるので、基板lの側
端部で電気力線が外部空間に洩れるのを極めて小さく抑
えることができる。According to the configuration of the present invention, even when the width of the optical waveguide device is narrow, since not only the main surface of the substrate 1 but also the side edges thereof are continuously covered with the high-resistance semiconductive film 6, the substrate l Leakage of electric lines of force into the external space at the side ends of the can be kept to an extremely low level.
したがって、2つの分岐光導波路2a、 2b近傍での
電界分布の乱れがほとんどなく、温度変化に起因する屈
折率変化が生ぜず光変調器の動作点シフトや消光比の変
動は起こらない。Therefore, there is almost no disturbance in the electric field distribution in the vicinity of the two branched optical waveguides 2a and 2b, no change in the refractive index due to temperature change occurs, and no shift in the operating point of the optical modulator or fluctuation in the extinction ratio occurs.
第1図は本発明の実施例を示す断面図である。 FIG. 1 is a sectional view showing an embodiment of the present invention.
図中、6(6a、 6c)は半導電性膜である。In the figure, 6 (6a, 6c) is a semiconductive film.
なお、前記従来例の諸図面で説明したものと同等の部分
については同一符号を付し、かつ、同等部分についての
説明は省略する。Note that the same reference numerals are given to the same parts as those explained in the drawings of the conventional example, and the explanation of the same parts will be omitted.
基板1には大きさ60mmX2 mm、厚さ1mmのL
tNbOsの2板の表面を鏡面研磨して使用した。Board 1 has an L with a size of 60 mm x 2 mm and a thickness of 1 mm.
The surfaces of two tNbOs plates were mirror polished and used.
この基板の上にTiを約90nmの厚さに真空蒸着し、
分岐光導波路2aおよび2bを含む光導波路2に相当す
る部分にTiが残るように通常のホトエツチング法で処
理したのち、約800°CでTiをLiNb0a中に熱
拡散して全光導波路2を形成した。On this substrate, Ti was vacuum-deposited to a thickness of about 90 nm,
After processing with a normal photoetching method so that Ti remains in the portion corresponding to the optical waveguide 2 including the branched optical waveguides 2a and 2b, the Ti is thermally diffused into LiNb0a at about 800°C to form the entire optical waveguide 2. did.
分岐光導波路部分の長さは50m m 、光導波路の幅
は全て7μmになるように調整した。バッファ層5は厚
さ300nmのSiO□膜を用いた。The length of the branched optical waveguide portion was adjusted to 50 mm, and the widths of all optical waveguides were adjusted to 7 μm. As the buffer layer 5, a SiO□ film with a thickness of 300 nm was used.
半導電性膜6(6a、 6c)は厚さ1100nのSi
膜を用い、基板1の一方の主面と一方の側端面とに。The semiconductive film 6 (6a, 6c) is made of Si with a thickness of 1100 nm.
A film is used on one main surface and one side end surface of the substrate 1.
たとえば、蒸着により形成し、その膜抵抗は第1および
第2の制御電極間で0.1〜5MΩの範囲になるように
調整した。第1の制御電極3はAu/Tiの2層膜を蒸
着したのち、分岐光導波路2aの上に巾9μmの電極形
状にパターンエツチングし、さらに、その上に厚さ3μ
mのAuをメツキにより付着形成した。第1の制御電極
3のエツジと基板lの側端部との間隔d1は0.1mm
になるようにした。For example, it was formed by vapor deposition, and the film resistance was adjusted to be in the range of 0.1 to 5 MΩ between the first and second control electrodes. The first control electrode 3 is formed by depositing a two-layer film of Au/Ti, then pattern-etching it into an electrode shape with a width of 9 μm on the branch optical waveguide 2a, and then forming a layer with a thickness of 3 μm on top of it.
m of Au was deposited by plating. The distance d1 between the edge of the first control electrode 3 and the side edge of the substrate l is 0.1 mm.
I made it so that
第2の制御電極4は第1の制御電極3と同様のプロセス
で巾広く、すなわち、接地電極として有効に働くように
第1の制御電極形成と同時形成した。The second control electrode 4 was formed to have a wide width using the same process as the first control electrode 3, that is, it was formed at the same time as the formation of the first control electrode so as to function effectively as a ground electrode.
第2図は本発明の効果を示す断面図で、縦軸に動作点シ
フトを、横軸に温度をとっである。FIG. 2 is a cross-sectional view showing the effects of the present invention, with the operating point shift plotted on the vertical axis and the temperature plotted on the horizontal axis.
図中、■の実線は前記本発明実施例の温度変化にともな
う動作点シフトを示すデータである。−方、2の一点鎖
線は第7図の■の一点鎖線と同じもので、すなわち、分
岐光導波路2a、 2bや第1および第2の制御電極3
,4の配置は前記第1図で説明した実施例と同一であり
、たマ異なるのは基板1の側端部に半導電性膜6aが形
成されていない従栽例のデータである0本発明実施例か
従来の光変調器に比較して、広い温度変化領域にわたっ
て極めて安定に動作可能であることがわかる。In the figure, the solid line (■) is data showing the operating point shift due to temperature change in the embodiment of the present invention. - On the other hand, the dashed-dotted line in 2 is the same as the dashed-dotted line in ② in FIG.
, 4 are the same as the embodiment described in FIG. It can be seen that compared to the inventive embodiment and the conventional optical modulator, it is possible to operate extremely stably over a wide range of temperature changes.
第3図は本発明の他の実施例を示す断面図である。本実
施例の場合は基板lの側面だけでなく、基板lのもう一
方の主面、すなわち、裏面にも半導電性膜6(6b)を
形成して、さらに、安定化効果を高めるようにしたもの
である。FIG. 3 is a sectional view showing another embodiment of the present invention. In the case of this embodiment, the semiconductive film 6 (6b) is formed not only on the side surface of the substrate l but also on the other main surface, that is, the back surface, of the substrate l to further enhance the stabilizing effect. This is what I did.
次に、本発明による素子を具体的に形成するための製造
方法の実施例を以下に示す。Next, an example of a manufacturing method for specifically forming an element according to the present invention will be shown below.
第4図は本発明の製造方法の主な工程を示す断面図であ
る。図中、7は溝、IOはウェーハである。FIG. 4 is a sectional view showing the main steps of the manufacturing method of the present invention. In the figure, 7 is a groove and IO is a wafer.
なお、前記の諸図面で説明したものと同等の部分につい
ては同一符号を付し、かつ、同等部分についての説明は
省略する。Note that the same reference numerals are given to the same parts as those explained in the above drawings, and the explanation of the same parts will be omitted.
工程(1):ウエーハ10.たとえば、直径100 m
mφ、厚さ1mmのZカットLiNbO5単結晶板の一
方の主面に、第1および第2の分岐光導波路2a、 2
bを有する光導波路2をTiを熱拡散することによって
多数形成する。Step (1): Wafer 10. For example, a diameter of 100 m
First and second branch optical waveguides 2a, 2 are formed on one main surface of a Z-cut LiNbO5 single crystal plate having a diameter of 1 mm and a thickness of 1 mm.
A large number of optical waveguides 2 having the shape b are formed by thermally diffusing Ti.
工程(2):上記処理ウェーへの上に厚さ300nmの
S i02膜からなるバッファ層5をCVD法で形成す
る。Step (2): A buffer layer 5 made of a Si02 film having a thickness of 300 nm is formed on the above-mentioned treated wafer by CVD.
工程(3)二上記処理ウェーハの第1の分岐光導波路2
aに近接して、たとえば、間隔d、=0.15mmとな
るように前記ウェーハlOに溝7.たとえば、巾0.3
mm、深さ0.4mmの溝を、たとえば、ダイヤモンド
ブレードを用いたカッティングマシンで形成する。Step (3) First branch optical waveguide 2 of the above-mentioned treated wafer
groove 7.a in the wafer lO, for example, with a spacing d, = 0.15 mm. For example, width 0.3
A groove with a diameter of 0.4 mm and a depth of 0.4 mm is formed using, for example, a cutting machine using a diamond blade.
工程(4)二上記処理ウェーハのバッファ層5の上と溝
7の周内側面に、半導電性膜6(6a、 6c)を、た
とえば、厚さ1100nのSi膜を、たとえば、蒸着に
より形成する。その膜抵抗は第1および第2の制御電極
間で0.1〜5MΩの範囲になるように調整すればよい
。Step (4) Form a semiconductive film 6 (6a, 6c), for example, a Si film with a thickness of 1100 nm, by vapor deposition on the buffer layer 5 of the second processed wafer and on the inner side surface of the groove 7. do. The membrane resistance may be adjusted to be in the range of 0.1 to 5 MΩ between the first and second control electrodes.
工程(5):上記処理ウェーハの分岐光導波路2a、2
bの上方に第1および第2の制御電極3.4を、たとえ
ば、厚さ0.3μmのAu/Tiの膜を蒸着したあと所
定の形状にパターンエツチングし、その上に厚さ3μm
のAuのメツキを行う。Step (5): Branch optical waveguides 2a, 2 of the above-mentioned treated wafer
Above the first and second control electrodes 3.4, for example, a 0.3 μm thick Au/Ti film is deposited, pattern etched into a predetermined shape, and a 3 μm thick Au/Ti film is deposited on top of that.
Perform Au plating.
工程(6)二上記処理ウェーハを前記溝7の部分とそれ
に直交する各デバイスの境界部分で、たとえば、0.2
mmφのワイヤソーを用いて切断し個別光導波路デバイ
スチップを形成する。Step (6) Second, the above-mentioned treated wafer is heated at the groove 7 portion and the boundary portion of each device perpendicular thereto, for example, by 0.2
It is cut using a mmφ wire saw to form individual optical waveguide device chips.
かくして、基板lの一方の主面と両方の側端面の一部分
までに、連続したSi膜からなる半導電性膜6(6a、
6c)が形成された本発明の光導波路デバイス、たと
えば、光変調器が得られる。Thus, the semiconductive film 6 (6a, 6a,
6c) of the present invention, such as an optical modulator, is obtained.
なお、半導電性膜6(6a、 6c)は側端面全体でな
く、本実施例のごとくその一部分であっても光導波路2
a、 2bの深さに対して十分に深いところまで被覆し
てあれば大きな効果が得られることを確認した。Note that the semiconductive film 6 (6a, 6c) does not cover the entire side end face, but may cover only a portion of the side end face as in this embodiment.
It was confirmed that a great effect can be obtained if the coating is sufficiently deep compared to the depths of a and 2b.
また、半導電性膜6は、たとえば、上記の範囲のごとき
抵抗値のものであれば、それによる光導波路デバイス、
たとえば、光変調器の高周波特性の劣化などは認められ
なかった。Further, if the semiconductive film 6 has a resistance value within the above range, for example, an optical waveguide device using the semiconductive film 6,
For example, no deterioration of the high frequency characteristics of the optical modulator was observed.
以上述べた実施例は数例を示したもので、光変調器だけ
でなく、方向性結合器型スイッチ、全反射型スイッチな
ど焦電効果を有する基板を用いたその他の光導波路デバ
イスにも有効であり、また、本発明の趣旨に添うもので
ある限り、使用する素材や構成9寸法、製作プロセスな
ど適宜好ましいもの、あるいはその組み合わせを用いる
ことができることは言うまでもない。The embodiments described above are just a few examples, and are effective not only for optical modulators but also for other optical waveguide devices using substrates with a pyroelectric effect, such as directional coupler switches and total internal reflection switches. It goes without saying that any preferable materials, configuration dimensions, manufacturing process, etc., or combinations thereof may be used as long as they comply with the spirit of the present invention.
以上説明したように、本発明によれば光導波路デバイス
の巾が細い場合でも、基板lの主面だけでなくその側端
部まで連続して高抵抗の半導電性膜6で覆っであるので
、基板lの側端部で電気力線が外部空間に洩れるのを極
めて小さく抑えることができる。したがって、2つの分
岐光導波路2a。As explained above, according to the present invention, even when the width of the optical waveguide device is narrow, not only the main surface of the substrate l but also the side edges thereof are continuously covered with the high-resistance semiconductive film 6. , leakage of electric lines of force into the external space at the side edges of the substrate l can be suppressed to an extremely low level. Therefore, two branched optical waveguides 2a.
2b近傍での電界分布の乱れがほとんどなく、温度変化
に起因する屈折率変化が生ぜず光変調器の動作点シフト
が起こらないので、光導波路デバイス、たとえば、光変
調器の性能および品質の向上に寄与するところが極めて
大きい。There is almost no disturbance in the electric field distribution near 2b, no refractive index change occurs due to temperature change, and no shift in the operating point of the optical modulator occurs, improving the performance and quality of optical waveguide devices, such as optical modulators. The contribution made to this is extremely large.
第1図は本発明の実施例を示す断面図、第2図は本発明
の効果を示す図、
第3図は本発明の他の実施例を示す断面図、第4図は本
発明の製造方法の主な工程を示す断面図、
第5図は従来の焦電効果の影響を防止する例をを示す断
面図、
第7図は焦電効果にもとづく動作点シフトを示す図、
第8図は光変調器の基本構成例を示す図、第9図は温度
変化による焦電効果を示す断面図である。
図において、
1は基板、2は光導波路、
2aおよび2bは第1および第2の分岐光導波路、3は
第1の制御電極、4は第2の制御電極、5はバッファ層
、6(6a、 6b、 6c)は半導電性膜、7は溝、
lOはウェーハである。
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−テdわB]箒 q 閏FIG. 1 is a cross-sectional view showing an embodiment of the present invention, FIG. 2 is a view showing the effects of the present invention, FIG. 3 is a cross-sectional view showing another embodiment of the present invention, and FIG. 4 is a manufacturing method of the present invention. A cross-sectional view showing the main steps of the method, Figure 5 is a cross-sectional view showing an example of preventing the effects of the conventional pyroelectric effect, Figure 7 is a view showing the operating point shift based on the pyroelectric effect, Figure 8 9 is a diagram showing an example of the basic configuration of an optical modulator, and FIG. 9 is a sectional view showing the pyroelectric effect due to temperature change. In the figure, 1 is a substrate, 2 is an optical waveguide, 2a and 2b are first and second branched optical waveguides, 3 is a first control electrode, 4 is a second control electrode, 5 is a buffer layer, 6 (6a , 6b, 6c) are semiconductive films, 7 is a groove,
lO is a wafer. :'re day F! /l Example request #VrtfmD number 1
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Claims (2)
方の主面上に、第1および第2の分岐光導波路(2a、
2b)を有する光導波路(2)を設け、前記分岐光導波
路(2a、2b)の上方に第1の制御電極(3)および
第2の制御電極(4)を配設してなる光導波路デバイス
において、 前記基板(1)の2つの主面のうちの少なくとも前記制
御電極(3、4)が配設された一方の主面と、前記基板
(1)の2つの側端面のうちの少なくとも入力信号用の
第1の制御電極(3)に近接した一方の側端面とに半導
電性膜(6)を形成することを特徴とした光導波路デバ
イス。(1) First and second branch optical waveguides (2a,
2b), and a first control electrode (3) and a second control electrode (4) are arranged above the branched optical waveguide (2a, 2b). At least one main surface of the two main surfaces of the substrate (1) on which the control electrodes (3, 4) are disposed, and at least one of the two side end surfaces of the substrate (1) An optical waveguide device characterized in that a semiconductive film (6) is formed on one side end surface close to a first control electrode (3) for signals.
(10)に第1および第2の分岐光導波路(2a、2b
)を有する光導波路(2)を形成する工程と、前記ウェ
ーハ(10)上にバッファ層(5)を形成する工程と、 前記第1の分岐光導波路(2a)に近接して前記ウェー
ハ(10)に溝(7)を形成する工程と、前記ウェーハ
(10)に形成されたバッファ層(5)の上と前記溝(
7)の内側面に半導電性膜(6)を形成する工程と、 前記分岐光導波路(2a、2b)の上方に前記バッファ
層(5)と半導電性膜(6)を介して第1および第2の
制御電極(3、4)を形成する工程と、前記溝(7)の
部分で前記ウェーハ(10)を切断して光導波路デバイ
スチップを形成する工程とを少なくとも含むことを特徴
とした請求項(1)記載の光導波路デバイスの製造方法
。(2) First and second branch optical waveguides (2a, 2b
), forming a buffer layer (5) on the wafer (10); ) forming a groove (7) on the buffer layer (5) formed on the wafer (10) and the groove (7) on the buffer layer (5) formed on the wafer (10);
7) forming a semi-conductive film (6) on the inner surface of the branch optical waveguide (2a, 2b); and a step of forming second control electrodes (3, 4), and a step of cutting the wafer (10) at the groove (7) to form an optical waveguide device chip. The method for manufacturing an optical waveguide device according to claim (1).
Priority Applications (1)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
JP1340430A JP2550730B2 (en) | 1989-12-29 | 1989-12-29 | Optical waveguide device and manufacturing method thereof |
Applications Claiming Priority (1)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
JP1340430A JP2550730B2 (en) | 1989-12-29 | 1989-12-29 | Optical waveguide device and manufacturing method thereof |
Publications (2)
Publication Number | Publication Date |
---|---|
JPH03202810A true JPH03202810A (en) | 1991-09-04 |
JP2550730B2 JP2550730B2 (en) | 1996-11-06 |
Family
ID=18336885
Family Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
JP1340430A Expired - Lifetime JP2550730B2 (en) | 1989-12-29 | 1989-12-29 | Optical waveguide device and manufacturing method thereof |
Country Status (1)
Country | Link |
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JP (1) | JP2550730B2 (en) |
Cited By (7)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
JPH07199134A (en) * | 1993-11-22 | 1995-08-04 | At & T Corp | Structure and method for photoelecton device for reducing temperature effect in lightguide modulator |
EP1321796A1 (en) * | 2000-09-18 | 2003-06-25 | Sumitomo Osaka Cement Co., Ltd. | Optical waveguide type optical modulator and production method therefor |
US7133580B2 (en) | 2002-11-19 | 2006-11-07 | Fujitsu Limited | Optical waveguide device and manufacturing method therefor |
JP2012068679A (en) * | 2011-12-19 | 2012-04-05 | Sumitomo Osaka Cement Co Ltd | Optical waveguide element |
JP2013130833A (en) * | 2011-12-22 | 2013-07-04 | Anritsu Corp | Light modulator |
JP2016142755A (en) * | 2015-01-29 | 2016-08-08 | 富士通オプティカルコンポーネンツ株式会社 | Optical modulator |
WO2017171096A1 (en) * | 2016-04-01 | 2017-10-05 | 住友大阪セメント株式会社 | Optical modulator module |
Citations (3)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
JPS57196166A (en) * | 1981-05-28 | 1982-12-02 | Matsushita Electric Ind Co Ltd | Voltage measurement device |
JPS62173428A (en) * | 1986-01-28 | 1987-07-30 | Fujitsu Ltd | Waveguide optical device |
JPH01232323A (en) * | 1988-03-11 | 1989-09-18 | Fujitsu Ltd | Light guide type modulator |
-
1989
- 1989-12-29 JP JP1340430A patent/JP2550730B2/en not_active Expired - Lifetime
Patent Citations (3)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
JPS57196166A (en) * | 1981-05-28 | 1982-12-02 | Matsushita Electric Ind Co Ltd | Voltage measurement device |
JPS62173428A (en) * | 1986-01-28 | 1987-07-30 | Fujitsu Ltd | Waveguide optical device |
JPH01232323A (en) * | 1988-03-11 | 1989-09-18 | Fujitsu Ltd | Light guide type modulator |
Cited By (12)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
JPH07199134A (en) * | 1993-11-22 | 1995-08-04 | At & T Corp | Structure and method for photoelecton device for reducing temperature effect in lightguide modulator |
EP1321796A1 (en) * | 2000-09-18 | 2003-06-25 | Sumitomo Osaka Cement Co., Ltd. | Optical waveguide type optical modulator and production method therefor |
EP1321796A4 (en) * | 2000-09-18 | 2004-04-14 | Sumitomo Osaka Cement Co Ltd | Optical waveguide type optical modulator and production method therefor |
US7133580B2 (en) | 2002-11-19 | 2006-11-07 | Fujitsu Limited | Optical waveguide device and manufacturing method therefor |
JP2012068679A (en) * | 2011-12-19 | 2012-04-05 | Sumitomo Osaka Cement Co Ltd | Optical waveguide element |
JP2013130833A (en) * | 2011-12-22 | 2013-07-04 | Anritsu Corp | Light modulator |
JP2016142755A (en) * | 2015-01-29 | 2016-08-08 | 富士通オプティカルコンポーネンツ株式会社 | Optical modulator |
WO2017171096A1 (en) * | 2016-04-01 | 2017-10-05 | 住友大阪セメント株式会社 | Optical modulator module |
JP2017187522A (en) * | 2016-04-01 | 2017-10-12 | 住友大阪セメント株式会社 | Optical Modulator Module |
CN108885361A (en) * | 2016-04-01 | 2018-11-23 | 住友大阪水泥股份有限公司 | Optical modulator module |
US10502988B2 (en) | 2016-04-01 | 2019-12-10 | Sumitomo Osaka Cement Co., Ltd. | Optical modulator module |
CN108885361B (en) * | 2016-04-01 | 2021-11-19 | 住友大阪水泥股份有限公司 | Optical modulator module |
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Publication number | Publication date |
---|---|
JP2550730B2 (en) | 1996-11-06 |
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