JPH05346560A - Optical modulator - Google Patents
Optical modulatorInfo
- Publication number
- JPH05346560A JPH05346560A JP15680292A JP15680292A JPH05346560A JP H05346560 A JPH05346560 A JP H05346560A JP 15680292 A JP15680292 A JP 15680292A JP 15680292 A JP15680292 A JP 15680292A JP H05346560 A JPH05346560 A JP H05346560A
- Authority
- JP
- Japan
- Prior art keywords
- waveguide
- width
- electrode pair
- optical modulator
- substrate
- 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
Links
Abstract
Description
【０００１】[0001]
【産業上の利用分野】本発明は、例えば光ファイバジャ
イロ等に使用される光変調器に関し、特に低消費電力化
を実現する光変調器に関する。BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an optical modulator used in, for example, an optical fiber gyro, and more particularly to an optical modulator for realizing low power consumption.
【０００２】[0002]
【従来の技術】図３に従来の光変調器の斜視図、及び図
４にその平面図を示す。図において、大きな電気光学効
果を有する例えばニオブ酸リチウムＬｉＮｂＯ3 の基板
１上に導波路２が設けられている。導波路２は、例えば
ＬｉＮｂＯ3 基板上にＴｉ金属膜を付着し、熱処理によ
りこれを内部へ拡散させることによって形成することが
できる。また、この導波路２の両側に沿って電極対３、
３’が設けられており、この電極対３と３’の間には電
位差が与えられる。2. Description of the Related Art FIG. 3 is a perspective view of a conventional optical modulator, and FIG. 4 is a plan view thereof. In the figure, a waveguide 2 is provided on a substrate 1 of, for example, lithium niobate LiNbO 3 having a large electro-optical effect. The waveguide 2 can be formed, for example, by depositing a Ti metal film on a LiNbO 3 substrate and diffusing it into the inside by heat treatment. In addition, electrode pairs 3 are provided along both sides of the waveguide 2,
3'is provided, and a potential difference is applied between the electrode pair 3 and 3 '.
【０００３】レーザダイオード等による光源４からの光
は導波路２内を伝搬し、電極対３、３’によって印加さ
れる電界の電圧によって変調され、受光器５に達する。
この電極対３、３’によって伝搬光の位相をπ変化させ
るために必要な半波長電圧Ｖπは、Light from a light source 4 such as a laser diode propagates in the waveguide 2, is modulated by the voltage of the electric field applied by the electrode pair 3, 3 ', and reaches the light receiver 5.
The half-wave voltage Vπ required to change the phase of the propagating light by π by the electrode pairs 3 and 3 ′ is
【０００４】[0004]
【数１】 で表される。ここでλは波長、Ｇは電極対３、３’の間
の距離、Γは定数、ｎはＬｉＮｂＯ3 の異常光に対する
屈折率、γはＬｉＮｂＯ3 の電気光学係数、Ｌは電極長
である。例として、光の波長λ＝１．５μｍとし、基板
のＸカットＹ伝搬を想定するとγ＝３０．８×１０-12
ｍ／Ｖとなる。又、その他の定数をΓ＝０．７、ｎ＝
２．２、Ｌ＝１０ｍｍとする。又、以上の場合に導波路
の幅Ｗは光ファイバとの接続損を小さくするために一般
的に１０μｍ程度は必要であるため、電極間の距離Ｇも
最小で１０μｍ程度となる。以上の数値を式（１）に代
入するとＶπ＝６．５Ｖとなる。さらに、伝搬光の位相
を２π変化させるには、Ｖ2 π＝１３．１Ｖもの電圧が
必要になる。[Equation 1] It is represented by. Here λ is the wavelength, the distance between the G electrode pair 3,3 ', gamma is a constant, n represents the refractive index with respect to extraordinary light of LiNbO 3, gamma electro-optical coefficient of LiNbO 3, L is an electrode length. As an example, assuming that the wavelength of light is λ = 1.5 μm and the X-cut Y propagation of the substrate is assumed, γ = 30.8 × 10 −12
m / V. Other constants are Γ = 0.7 and n =
2.2, L = 10 mm. In the above case, the width W of the waveguide is generally required to be about 10 μm in order to reduce the connection loss with the optical fiber. Therefore, the distance G between the electrodes is about 10 μm at the minimum. Substituting the above numerical values into the equation (1) results in Vπ = 6.5V. Furthermore, in order to change the phase of the propagating light by 2π, a voltage of V 2 π = 13.1V is required.
【０００５】[0005]
【発明が解決しようとする課題】従って、この従来の光
変調器では、消費電力が大きいという問題がある。この
消費電力を小さくするためには式（１）において、従来
の構造ではＬを大きくするかしかなく、即ち、電極長が
長くなり、光変調器全体の寸法が大きくなるという問題
がある。本発明は、かかる問題点に鑑み、光変調器全体
の寸法を大きくせずに、低消費電力化を図ることができ
る光変調器を提供することを目的とする。Therefore, this conventional optical modulator has a problem of high power consumption. In order to reduce the power consumption, in the formula (1), there is no choice but to increase L in the conventional structure, that is, the electrode length becomes long and the size of the entire optical modulator becomes large. SUMMARY OF THE INVENTION In view of the above problems, it is an object of the present invention to provide an optical modulator that can reduce power consumption without increasing the size of the entire optical modulator.
【０００６】[0006]
【課題を解決するための手段】上記目的を達成するため
に本発明では、電気光学効果を有する基板と、基板上に
設けられた導波路と、導波路の両側に沿って形成された
電極対を備えた光変調器において、電極対に挟まれた導
波路の幅を他の導波路の部分の幅に比較して小さくす
る。In order to achieve the above object, the present invention provides a substrate having an electro-optical effect, a waveguide provided on the substrate, and electrode pairs formed along both sides of the waveguide. In the optical modulator including, the width of the waveguide sandwiched by the electrode pair is made smaller than the widths of the portions of the other waveguides.
【０００７】[0007]
【作用】本発明では、電極対に挟まれた導波路の部分を
他の部分の幅よりも小さくすることにより結果として電
極対間の距離Ｇを小さくすることができる。従って、前
述の（１）式より必要な電圧値を小さくでき、消費電圧
を小さくすることができる。In the present invention, the portion of the waveguide sandwiched by the electrode pair is made smaller than the width of the other portion, and as a result, the distance G between the electrode pair can be reduced. Therefore, the required voltage value can be reduced and the consumption voltage can be reduced according to the equation (1).
【０００８】[0008]
【実施例】図１は、本発明による光変調器の１実施例の
斜視図である。図において、従来例と同一の部分には同
一の符号を付す。本実施例では、電気光学効果を有する
例えばＬｉＮｂＯ3 の基板１と、その基板１上に設けら
れた導波路２０と、導波路２０の両側に沿って形成され
た電極対３０、３０’を備えている。導波路２０は、第
１部分２０−１、テーパ部分２０−２及び第２部分２０
−３から成る。第２部分２０−３は、電極対３０、３
０’によって挟まれた部分であり、その幅は第１部分２
０−１に比較して小さく第１部分２０−１と第２部分２
０−３との間がテーパ部分２０−２となっている。第２
部分２０−３の幅を第１部分２０−１の１／２にした場
合に半波長電圧を前述の（１）式と比較して求めると、1 is a perspective view of an embodiment of an optical modulator according to the present invention. In the figure, the same parts as those in the conventional example are designated by the same reference numerals. In this embodiment, a substrate 1 made of, for example, LiNbO 3 having an electro-optical effect, a waveguide 20 provided on the substrate 1, and electrode pairs 30, 30 ′ formed along both sides of the waveguide 20 are provided. ing. The waveguide 20 includes a first portion 20-1, a tapered portion 20-2, and a second portion 20.
-3. The second portion 20-3 includes the electrode pairs 30, 3
It is a part sandwiched by 0's and its width is the first part 2
The first portion 20-1 and the second portion 2 are smaller than 0-1.
The taper portion 20-2 is between 0-3. Second
When the width of the portion 20-3 is set to ½ of the width of the first portion 20-1, the half-wave voltage is calculated by comparing with the above equation (1),
【０００９】[0009]
【数２】 となり、従来の半波長電圧の１／２、消費電力が１／４
となり、かなりの省電力化を図ることができる。テーパ
部分２０−２の形成に伴う全長への影響を考慮すると、
テーパ部分２０−２を片側０．５°の傾斜とすると、テ
ーパ部分２０−２の長手方向の長さは約０．３ｍｍ程度
であり、両方のテーパ部分２０−２、２０−２を合わせ
ても約０．６ｍｍ程度と、電極長の１割にも満たずその
影響は小さい。又、第１部分２０−１の幅は小さくする
必要がないので光ファイバとの接続損を悪化させること
はない。次に、図２には導波路の変形例を示す。[Equation 2] Is half the conventional half-wave voltage and 1/4 the power consumption.
Therefore, it is possible to achieve considerable power saving. Considering the influence on the total length due to the formation of the tapered portion 20-2,
If the taper portion 20-2 is inclined at 0.5 ° on one side, the length in the longitudinal direction of the taper portion 20-2 is about 0.3 mm, and both taper portions 20-2 and 20-2 are combined. Is about 0.6 mm, which is less than 10% of the electrode length and its influence is small. Further, since it is not necessary to reduce the width of the first portion 20-1, the connection loss with the optical fiber will not be deteriorated. Next, FIG. 2 shows a modification of the waveguide.
【００１０】図２（ａ）は片側にのみテーパを形成した
例であり、図２（ｂ）はテーパ部分を曲線状に形成した
例であり、図２（ｃ）は片側にのみ曲線部分を形成した
例である。いずれの例の場合であっても、電極対によっ
て挟まれる部分の導波路の幅を他の導波路の部分の幅に
比較して小さくすることにより、結果として電極対間の
距離を小さくなるように構成することができる。FIG. 2A shows an example in which a taper is formed only on one side, FIG. 2B shows an example in which the taper portion is formed in a curved shape, and FIG. 2C shows a curve portion in only one side. It is an example of forming. In either case, the width of the waveguide between the electrode pairs is made smaller than the width of the other waveguides so that the distance between the electrode pairs is reduced. Can be configured to.
【００１１】[0011]
【発明の効果】以上説明したように、本発明による光変
調器によれば電気光学効果を有する基板と、基板上に設
けられた導波路と、導波路の両側に沿って形成された電
極対を備えた光変調器において、電極対に挟まれる導波
路の幅を他の導波路の部分の幅に比較して小さくするこ
ととしたので、結果として電極対間の距離を小さくで
き、従って、全体の寸法を大きくせずに必要な電圧値を
小さくでき、消費電圧を小さくすることができる。As described above, according to the optical modulator of the present invention, the substrate having the electro-optical effect, the waveguide provided on the substrate, and the electrode pair formed along both sides of the waveguide are provided. In the optical modulator provided with, since the width of the waveguide sandwiched by the electrode pair is made smaller than the widths of other waveguide portions, as a result, the distance between the electrode pair can be reduced, and therefore, The required voltage value can be reduced without increasing the overall size, and the consumption voltage can be reduced.
【図１】本発明による光変調器の一実施例を示す斜視図
である。FIG. 1 is a perspective view showing an embodiment of an optical modulator according to the present invention.
【図２】本発明による光変調器の光導波路の変形例を示
す部分平面図である。FIG. 2 is a partial plan view showing a modified example of the optical waveguide of the optical modulator according to the present invention.
【図３】従来の光変調器の斜視図である。FIG. 3 is a perspective view of a conventional optical modulator.
【図４】図３の平面図である。FIG. 4 is a plan view of FIG.
１ 基板 ２０ 導波路 ３０、３０’ 電極対 1 substrate 20 waveguide 30, 30 'electrode pair
Claims (1)
設けられた導波路と、導波路の両側に沿って形成された
電極対を備えた光変調器において、 電極対に挟まれる導波路の幅を他の導波路の部分の幅に
比較して小さくすることを特徴とする光変調器。1. An optical modulator including a substrate having an electro-optic effect, a waveguide provided on the substrate, and an electrode pair formed along both sides of the waveguide, wherein the waveguide is sandwiched between the electrode pair. The optical modulator is characterized in that the width of the waveguide is made smaller than the widths of other waveguide portions.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP15680292A JPH05346560A (en) | 1992-06-16 | 1992-06-16 | Optical modulator |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP15680292A JPH05346560A (en) | 1992-06-16 | 1992-06-16 | Optical modulator |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| JPH05346560A true JPH05346560A (en) | 1993-12-27 |
Family
ID=15635646
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP15680292A Pending JPH05346560A (en) | 1992-06-16 | 1992-06-16 | Optical modulator |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JPH05346560A (en) |
Cited By (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| GB2376082A (en) * | 2001-06-01 | 2002-12-04 | Bookham Technology Ltd | Attenuating structures for integrated optical devices |
| WO2003023500A1 (en) * | 2001-09-05 | 2003-03-20 | Ngk Insulators, Ltd. | Optical device |
| US7840098B2 (en) | 2005-01-20 | 2010-11-23 | Intel Corporation | Variable optical power limiter |
-
1992
- 1992-06-16 JP JP15680292A patent/JPH05346560A/en active Pending
Cited By (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| GB2376082A (en) * | 2001-06-01 | 2002-12-04 | Bookham Technology Ltd | Attenuating structures for integrated optical devices |
| WO2003023500A1 (en) * | 2001-09-05 | 2003-03-20 | Ngk Insulators, Ltd. | Optical device |
| US7840098B2 (en) | 2005-01-20 | 2010-11-23 | Intel Corporation | Variable optical power limiter |
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