JPH0283523A - Optical isolator - Google Patents
Optical isolatorInfo
- Publication number
- JPH0283523A JPH0283523A JP23703388A JP23703388A JPH0283523A JP H0283523 A JPH0283523 A JP H0283523A JP 23703388 A JP23703388 A JP 23703388A JP 23703388 A JP23703388 A JP 23703388A JP H0283523 A JPH0283523 A JP H0283523A
- Authority
- JP
- Japan
- Prior art keywords
- analyzer
- main axis
- crystal
- polarizer
- polarized light
- 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
- 230000003287 optical effect Effects 0.000 title claims abstract description 50
- 239000013078 crystal Substances 0.000 claims abstract description 16
- 230000000694 effects Effects 0.000 claims abstract description 9
- 239000004065 semiconductor Substances 0.000 abstract description 21
- 239000000758 substrate Substances 0.000 abstract description 8
- 230000008878 coupling Effects 0.000 abstract description 5
- 238000010168 coupling process Methods 0.000 abstract description 5
- 238000005859 coupling reaction Methods 0.000 abstract description 5
- 239000002223 garnet Substances 0.000 abstract description 3
- 238000010586 diagram Methods 0.000 description 3
- 230000010287 polarization Effects 0.000 description 3
- XEEYBQQBJWHFJM-UHFFFAOYSA-N Iron Chemical compound [Fe] XEEYBQQBJWHFJM-UHFFFAOYSA-N 0.000 description 2
- 230000001154 acute effect Effects 0.000 description 2
- 239000000463 material Substances 0.000 description 2
- 239000013307 optical fiber Substances 0.000 description 2
- 230000001902 propagating effect Effects 0.000 description 2
- GWEVSGVZZGPLCZ-UHFFFAOYSA-N titanium dioxide Inorganic materials O=[Ti]=O GWEVSGVZZGPLCZ-UHFFFAOYSA-N 0.000 description 2
- 229910013637 LiNbO2 Inorganic materials 0.000 description 1
- IBXOPEGTOZQGQO-UHFFFAOYSA-N [Li].[Nb] Chemical compound [Li].[Nb] IBXOPEGTOZQGQO-UHFFFAOYSA-N 0.000 description 1
- 230000010354 integration Effects 0.000 description 1
- 229910052742 iron Inorganic materials 0.000 description 1
- MTRJKZUDDJZTLA-UHFFFAOYSA-N iron yttrium Chemical compound [Fe].[Y] MTRJKZUDDJZTLA-UHFFFAOYSA-N 0.000 description 1
- 238000000034 method Methods 0.000 description 1
- 229910052758 niobium Inorganic materials 0.000 description 1
- 239000010955 niobium Substances 0.000 description 1
- GUCVJGMIXFAOAE-UHFFFAOYSA-N niobium atom Chemical compound [Nb] GUCVJGMIXFAOAE-UHFFFAOYSA-N 0.000 description 1
Classifications
-
- G—PHYSICS
- G02—OPTICS
- G02B—OPTICAL ELEMENTS, SYSTEMS OR APPARATUS
- G02B5/00—Optical elements other than lenses
- G02B5/30—Polarising elements
- G02B5/3083—Birefringent or phase retarding elements
-
- G—PHYSICS
- G02—OPTICS
- G02B—OPTICAL ELEMENTS, SYSTEMS OR APPARATUS
- G02B6/00—Light guides; Structural details of arrangements comprising light guides and other optical elements, e.g. couplings
- G02B6/24—Coupling light guides
- G02B6/42—Coupling light guides with opto-electronic elements
- G02B6/4201—Packages, e.g. shape, construction, internal or external details
- G02B6/4204—Packages, e.g. shape, construction, internal or external details the coupling comprising intermediate optical elements, e.g. lenses, holograms
- G02B6/4207—Packages, e.g. shape, construction, internal or external details the coupling comprising intermediate optical elements, e.g. lenses, holograms with optical elements reducing the sensitivity to optical feedback
- G02B6/4208—Packages, e.g. shape, construction, internal or external details the coupling comprising intermediate optical elements, e.g. lenses, holograms with optical elements reducing the sensitivity to optical feedback using non-reciprocal elements or birefringent plates, i.e. quasi-isolators
- G02B6/4209—Optical features
Abstract
Description
【発明の詳細な説明】
（産業上の利用分野）
この発明は、光通信システムに用いられる光アイソレー
タに関するものである。DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to an optical isolator used in an optical communication system.
（従来の技術）
光通信システムにおける光信号源である半導体レーザは
、これに結合される光ファイバ、光スイツチ合分波器等
の端面や光フアイバ同士の接続点等からの反射光が半導
体レーザに再注入されると、動作特性が大幅に劣化する
。従って、そのような反射光が半導体レーザに再入射す
るのを阻止する光アイソレータは、光通信システムの安
定性や信頼性を向上させるための重要なデバイスの１つ
である。一般に、光アイソレータとしては、ファラデー
効果を有する結晶の両端部にそれぞれ偏光子および検光
子をそれらの主軸の方向が互いに４５°傾くように配置
して構成されている。（例えば、平山博（繻）「光通信
要覧」（株式会社科学新聞社、１９８４年８月発行）の
第５４７〜５７１頁の記載を参照。）この構成で、たと
えば、偏光子の主軸に一致した方向の直線偏光を入射す
ると、光アイソレータから出射する光の偏光は、その入
射光の直線偏光に対して主軸が４５°傾いた直線偏光と
なる。(Prior Art) A semiconductor laser is an optical signal source in an optical communication system, and the reflected light from the end face of an optical fiber coupled to the semiconductor laser, an optical switch multiplexer/demultiplexer, etc., or a connection point between optical fibers is reflected from the semiconductor laser. If re-injected, the operating characteristics will be significantly degraded. Therefore, an optical isolator that prevents such reflected light from entering the semiconductor laser again is one of the important devices for improving the stability and reliability of optical communication systems. Generally, an optical isolator is constructed by arranging a polarizer and an analyzer at both ends of a crystal having a Faraday effect so that their principal axes are inclined at 45 degrees to each other. (For example, see the description on pages 547 to 571 of Hiroshi Hirayama's "Optical Communication Handbook" (Kagaku Shinbunsha Co., Ltd., August 1984).) With this configuration, for example, When linearly polarized light in such a direction is incident, the polarized light emitted from the optical isolator becomes linearly polarized light whose principal axis is inclined at 45 degrees with respect to the linearly polarized light of the incident light.
（発明が解決しようとする課題）
一般に、光導波路型の光スィッチ、合分波器等の先導波
路デバイスは、それを伝搬する光の偏光が、その光導波
路デバイスの導波路断面内で基板表面と平行または垂直
な方向に主軸を有する直線偏光の場合に、良好な動特性
を得る。また一般に半導体レーザから出射する光の偏光
は基板表面に平行な方向に主軸を有する直線偏光である
。このような光導波路デバイスと半導体レーザとを良好
な動特性を得るように光アイソレータを介して結合する
場合には、前に述べたように、光アイソレータの出射光
の直線偏光の主軸が、入射光の直線偏光の主軸に対して
４５°傾くため、光導波路デバイスを半導体レーザに対
して４５°傾けて配置する必要があり、構成上複雑にな
る欠点があった。また、このように４５°傾けて配置し
なければならないため、同一基板上に集積化することが
困難であった。(Problem to be Solved by the Invention) In general, in an optical waveguide-type optical switch, multiplexer/demultiplexer, or other leading waveguide device, the polarization of the light propagating through it is within the cross section of the waveguide of the optical waveguide device. Good dynamic characteristics are obtained in the case of linearly polarized light having its principal axis in a direction parallel or perpendicular to. Further, generally, the polarized light emitted from a semiconductor laser is linearly polarized light whose main axis is parallel to the substrate surface. When such an optical waveguide device and a semiconductor laser are coupled via an optical isolator to obtain good dynamic characteristics, the main axis of the linearly polarized light of the output light of the optical isolator is aligned with the incident light as described above. Since the optical waveguide device is inclined at 45 degrees with respect to the main axis of linearly polarized light, it is necessary to arrange the optical waveguide device at an angle of 45 degrees with respect to the semiconductor laser, which has the disadvantage of complicating the structure. Furthermore, since they had to be arranged at an angle of 45 degrees, it was difficult to integrate them on the same substrate.
本発明は、上述のような欠点を除去して、半導体レーザ
と先導波路デバイスとの結合を構成上容易にする光アイ
ソレータを提供することにある。SUMMARY OF THE INVENTION The object of the present invention is to provide an optical isolator that eliminates the above-mentioned drawbacks and facilitates the coupling between a semiconductor laser and a guiding waveguide device.
（課題を解決するための手段）
本発明の光アイソレータは、ファラデー効果を有する結
晶と該結晶の入力端に設けた偏光子と、前記結晶の出力
端に前記偏光子の主軸と主軸の方向を４５°傾けて設け
た検光子とからなる光アイソレータにおいて、前記検子
の出力端に半波長板を備えたことを特徴とする。(Means for Solving the Problems) The optical isolator of the present invention includes a crystal having a Faraday effect, a polarizer provided at the input end of the crystal, and a main axis of the polarizer and a direction of the main axis at the output end of the crystal. An optical isolator comprising an analyzer installed at an angle of 45 degrees, characterized in that a half-wave plate is provided at the output end of the analyzer.
（作用）
本発明の光′アイソレータにおいて、偏光子の主軸に一
致した直線偏光を入射すると、検光子からの出射光は、
前にも述べたように入射光に対して４５°傾いた方向の
直線偏光となり、半波長板に入射する。そこで、その光
は、半波長板により、半波要分だけ位相差を生じ、その
半波長板の主軸の方向によって決まる特定の方向の主軸
を有する直線偏光に変換される。ここで、その変換され
た直線偏光の主軸の方向は、半波長板の主軸が検光子の
主軸と偏光子の主軸との成す角の二等分線上にあれば、
入射光の直線偏光と同じ方向となる。また、半波長板の
主軸が検光子の主軸と偏光子の主軸に垂直な方向の軸と
の成す角の二等分線上にあれば、入射光の直線偏光の主
軸に垂直な方向となる。一方、光アイソレータへの反射
光は、従来と同様に光アイソレータのファラデー回転方
式により阻止される。(Function) In the optical isolator of the present invention, when linearly polarized light that coincides with the main axis of the polarizer is incident, the light emitted from the analyzer is
As mentioned before, the light becomes linearly polarized light in a direction inclined at 45 degrees with respect to the incident light, and enters the half-wave plate. Therefore, the light is converted into linearly polarized light having a principal axis in a specific direction determined by the direction of the principal axis of the half-wave plate, which generates a phase difference corresponding to the half-wave length by the half-wave plate. Here, the direction of the principal axis of the converted linearly polarized light is, if the principal axis of the half-wave plate is on the bisector of the angle formed by the principal axis of the analyzer and the principal axis of the polarizer,
The direction is the same as the linearly polarized light of the incident light. Furthermore, if the principal axis of the half-wave plate is on the bisector of the angle formed by the principal axis of the analyzer and the axis perpendicular to the principal axis of the polarizer, the direction is perpendicular to the principal axis of the linearly polarized light of the incident light. On the other hand, the reflected light to the optical isolator is blocked by the Faraday rotation method of the optical isolator, as in the conventional case.
（実施例）
以下、本発明について図面を参照して説明する。第１図
は本発明の一実施例の構成を示す斜視図である。第２図
（ａ）、（ｂ）は偏光子、検光子、半波長板各々の主軸
の方向を示す図である。(Example) The present invention will be described below with reference to the drawings. FIG. 1 is a perspective view showing the configuration of an embodiment of the present invention. FIGS. 2(a) and 2(b) are diagrams showing the directions of the principal axes of the polarizer, analyzer, and half-wave plate.
ファラデー効果を有するイツトリウム鉄ガーネッｌ−（
ＹＩＧ）結晶１の両端部に主軸の方向が互いに４５°傾
いた偏光子２）検光子３が配置されている。なお、偏光
子２）検光子３にはルチルプリズムを用いている。半導
体レーザ４と偏光子２とは、集束性ロッドレンズ５を介
して結合されており、半導体レーザの出射光である直線
偏光の主軸と偏光子２の主軸との方向は一致するように
配置しである。Yztrium iron garnet with Faraday effect (
YIG) Polarizers 2) Analyzers 3 whose principal axes are tilted at 45° to each other are arranged at both ends of the crystal 1. Note that a rutile prism is used for the polarizer 2 and the analyzer 3. The semiconductor laser 4 and the polarizer 2 are coupled through a focusing rod lens 5, and are arranged so that the main axis of the linearly polarized light that is the output light of the semiconductor laser and the main axis of the polarizer 2 are aligned. It is.
方、検光子３の出射端には、検光子３の主軸２２と偏光
子２の主軸に垂直な方向の軸２３との成す角の内の鋭角
（２θ＝４５°）の二等分線上、つまり検光子３の主軸
に対して２２．５°傾いた方向に主軸（２４）を有する
半波長板６（第２図（ａ）参照）が接続されている。そ
の後にニオブサンリチウム（ＬｉＮｂＯ２）を材料とし
た導波路型光スイッチ７が半導体レーザ４と平行に接続
されている。一般にニオブサンリチウムからなる導波路
型光スイッチは、その伝搬光として導波路断面内で基板
表面に垂直な方向に主軸を有する直線偏光の場合に良好
な動作特性が得られる。On the other hand, at the output end of the analyzer 3, on the bisector of an acute angle (2θ=45°) between the principal axis 22 of the analyzer 3 and the axis 23 perpendicular to the principal axis of the polarizer 2, That is, a half-wave plate 6 (see FIG. 2(a)) having a principal axis (24) inclined at 22.5 degrees with respect to the principal axis of the analyzer 3 is connected. Thereafter, a waveguide type optical switch 7 made of lithium niobium (LiNbO2) is connected in parallel to the semiconductor laser 4. In general, a waveguide type optical switch made of niobium sanlithium has good operating characteristics when the propagating light is linearly polarized light having a principal axis in a direction perpendicular to the substrate surface within the cross section of the waveguide.
さて、上述のような構成で、半導体レーザ４から出射し
た、その半導体レーザ４の基板表面に平行な方向に主軸
を有する直線偏光は、ロンドレンズ５により、主軸がそ
の直線偏光に一致した偏光子２に接合される。その後、
その直線偏光は、結晶１により、主軸を一方向に回転さ
せられ、検光子３の主軸の方向に一致した主軸を有する
直線偏光に変換され、検光子３を出射する。ここまでは
、その直線偏光は、従来の光アイソレータと同様の作用
をうける。その後、その直後偏光は半波長板６により、
半波要分だけを位相差を生じることにより主軸を先程の
結晶１で受けた回転方向と同じ方向に回転させられ出射
する。すなわち、半導体レーザ４の出射光である直線偏
光の主軸に対して９０’傾いた方向に主軸を有する直線
偏光が半波長板６から出射する。したがって導波路型光
スイッチ７には、その導波路断面内で基板表面に垂直な
方向に主軸を有する直線偏光が入射するため、導波路型
光スイッチ７は良好な動特性を示す。このように、半導
体レーザ４と導波路型光スイッチ７とを平行に配置でき
るので、結合系の構造が簡単となる。例えば、半導体レ
ーザ４と導波路型光スイッチ７を同一基板上に平行に配
置することもできるので結合系の集積化も容易となる。Now, with the above-described configuration, the linearly polarized light emitted from the semiconductor laser 4 and having its principal axis in a direction parallel to the substrate surface of the semiconductor laser 4 is converted into a polarizer whose principal axis coincides with the linearly polarized light by the Rondo lens 5. 2. after that,
The linearly polarized light has its principal axis rotated in one direction by the crystal 1, is converted into linearly polarized light having a principal axis that coincides with the direction of the principal axis of the analyzer 3, and is emitted from the analyzer 3. Up to this point, the linearly polarized light is treated similarly to a conventional optical isolator. Immediately thereafter, the polarized light is polarized by a half-wave plate 6.
By creating a phase difference only for the half-wave component, the main axis is rotated in the same direction as the direction of rotation received by the crystal 1, and the light is emitted. That is, linearly polarized light whose main axis is inclined by 90' with respect to the main axis of the linearly polarized light that is the light emitted from the semiconductor laser 4 is emitted from the half-wave plate 6 . Therefore, since linearly polarized light having a principal axis in a direction perpendicular to the substrate surface is incident on the waveguide optical switch 7 within the cross section of the waveguide, the waveguide optical switch 7 exhibits good dynamic characteristics. In this way, since the semiconductor laser 4 and the waveguide optical switch 7 can be arranged in parallel, the structure of the coupling system is simplified. For example, since the semiconductor laser 4 and the waveguide optical switch 7 can be arranged in parallel on the same substrate, integration of the coupling system becomes easy.
本実施例では半導体レーザからの出射光が導波路断面内
で基板表面に垂直な方向に主軸を有する直接偏光に変換
される場合を説明したが、必要に応じ、半導体レーザか
らの出射光が基板表面に平行な方向に主軸を有する直接
偏光に変換されるように半波長板６の主軸の方向を所望
の方向にして配置しても良い。これは例えば、半波長板
の主軸の方向を第２図（ｂ）に示すように偏光子の主軸
と検光子の主軸との成す角の二等分線上に一致させれば
よい。In this example, the case where the emitted light from the semiconductor laser is converted into directly polarized light having the main axis in the direction perpendicular to the substrate surface within the cross section of the waveguide has been described. The half-wave plate 6 may be arranged with its principal axis in a desired direction so that it is converted into directly polarized light having its principal axis in a direction parallel to the surface. This can be done, for example, by aligning the direction of the principal axis of the half-wave plate with the bisector of the angle formed by the principal axis of the polarizer and the principal axis of the analyzer, as shown in FIG. 2(b).
また、本実施例では、偏光子２の主軸に垂直な方向の軸
と検光子３の主軸との成す角の内、鋭角（４５°）の二
等分線上に半波長板６の主軸を配置したが、鈍角（１３
５°）の二等分線上に半波長板６の主軸を配置しても良
い。In addition, in this embodiment, the principal axis of the half-wave plate 6 is arranged on the bisector of an acute angle (45°) of the angle formed by the axis perpendicular to the principal axis of the polarizer 2 and the principal axis of the analyzer 3. However, the obtuse angle (13
The main axis of the half-wave plate 6 may be placed on the bisector of 5°).
また、本実施例では導波路型光デバイスに導波路型光ス
イッチを用いたが他の光デバイス（例えば合分波器、偏
光スプリッタ等）を用いても良い。Further, in this embodiment, a waveguide type optical switch is used as the waveguide type optical device, but other optical devices (for example, a multiplexer/demultiplexer, a polarization splitter, etc.) may be used.
また、本実施例では、ファラデー効果を有する材料とし
て、イツトリウム鉄ガーネットを用いたが、これに限定
されず、ファラデー効果を有する材料であればよい。Further, in this embodiment, yttrium iron garnet is used as the material having the Faraday effect, but the present invention is not limited to this, and any material having the Faraday effect may be used.
また、本実施例では、偏光子２）検光子３にルチルプリ
ズムを用いたがこれに限定されず例えばロッションプリ
ズム等を用いても良い。Further, in this embodiment, a rutile prism is used for the polarizer 2 and the analyzer 3, but the present invention is not limited to this, and for example, a Rochon prism or the like may be used.
また、本実施例では、光デバイスどして導波路型を用い
たが、これに限定されず、偏光依存性のある光デバイス
であれば良い。Further, in this embodiment, a waveguide type optical device is used, but the present invention is not limited to this, and any optical device having polarization dependence may be used.
（発明の効果）
以上述べたごとく本発明によれば、半導体レーザと平行
に導波路型光デバイスを配置することができる。光アイ
ツレ、−夕を構成でき、半導体レーザと光デバイスとの
結合系の構造が簡単になる。(Effects of the Invention) As described above, according to the present invention, a waveguide type optical device can be arranged in parallel with a semiconductor laser. It is possible to configure an optical circuit, and the structure of the coupling system between the semiconductor laser and the optical device is simplified.
第１図は本発明の一実施例の構成を示す図である。第２
図（ａ）、（ｂ）は偏光子、検光子、半波長板各々の主
軸の方向を示す図である。
図において、１・・・結晶、２・・・偏光子、３・・・
検光子、４１．・半導体レーザ、５・・・ロッドレンズ
、６・・・半波長板、７・・・光スィッチである。FIG. 1 is a diagram showing the configuration of an embodiment of the present invention. Second
Figures (a) and (b) are diagrams showing the directions of the principal axes of the polarizer, analyzer, and half-wave plate. In the figure, 1...crystal, 2...polarizer, 3...
Analyzer, 41. - Semiconductor laser, 5... rod lens, 6... half-wave plate, 7... optical switch.
Claims (1)
設けた偏光子と、前記結晶の出力端に前記偏光子の主軸
と主軸の方向を４５°傾けて設けた検光子とからなる光
アイソレータにおいて、前記検光子の出力端に半波長板
を備えたことを特徴とする光アイソレータ。（２）特許
請求の範囲第（１）項記載の光アイソレータにおいて、
前記検光子の主軸と前記偏光子の主軸との成す角の二等
分線上に前記半波長板の主軸を一致させたことを特徴と
する光アイソレータ。 （３）特許請求の範囲第（１）項記載の光アイソレータ
において前記検光子の主軸と前記偏光子の主軸に垂直な
方向の軸との成す角の二等分線上に前記半波長板の主軸
を一致させたことを特徴とする光アイソレータ。[Scope of Claims] (1) A crystal having a Faraday effect, a polarizer provided at the input end of the crystal, and a detector provided at the output end of the crystal with the main axis of the polarizer and the direction of the main axis inclined by 45 degrees. What is claimed is: 1. An optical isolator comprising photons, characterized in that a half-wave plate is provided at the output end of the analyzer. (2) In the optical isolator according to claim (1),
An optical isolator characterized in that the principal axis of the half-wave plate is aligned with the bisector of the angle formed by the principal axis of the analyzer and the principal axis of the polarizer. (3) In the optical isolator according to claim (1), the principal axis of the half-wave plate is located on the bisector of the angle formed by the principal axis of the analyzer and the axis perpendicular to the principal axis of the polarizer. An optical isolator characterized by matching the following.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP23703388A JPH0283523A (en) | 1988-09-20 | 1988-09-20 | Optical isolator |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP23703388A JPH0283523A (en) | 1988-09-20 | 1988-09-20 | Optical isolator |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| JPH0283523A true JPH0283523A (en) | 1990-03-23 |
Family
ID=17009401
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP23703388A Pending JPH0283523A (en) | 1988-09-20 | 1988-09-20 | Optical isolator |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JPH0283523A (en) |
Cited By (10)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US5321448A (en) * | 1991-05-17 | 1994-06-14 | Casio Computer Co., Ltd. | Liquid crystal projector |
| US5398086A (en) * | 1991-03-20 | 1995-03-14 | Mitsubishi Denki Kabushiki Kaisha | Projection type display device |
| US5539574A (en) * | 1994-12-21 | 1996-07-23 | At&T Corp. | Optical isolator with fabry-perot ripple reduction |
| US5631771A (en) * | 1991-09-19 | 1997-05-20 | Lucent Technologies Inc. | Optical isolator with polarization dispersion and differential transverse deflection correction |
| US5812304A (en) * | 1995-08-29 | 1998-09-22 | Fujitsu Limited | Faraday rotator which generates a uniform magnetic field in a magnetic optical element |
| US5844710A (en) * | 1996-09-18 | 1998-12-01 | Fujitsu Limited | Faraday rotator and optical device employing the same |
| US5867300A (en) * | 1996-03-01 | 1999-02-02 | Fujitsu Limited | Variable optical attenuator which applies a magnetic field to a faraday element to rotate the polarization of a light signal |
| US5889609A (en) * | 1992-07-31 | 1999-03-30 | Fujitsu Limited | Optical attenuator |
| US6018411A (en) * | 1996-11-29 | 2000-01-25 | Fujitsu Limited | Optical device utilizing magneto-optical effect |
| JP2020503687A (en) * | 2016-12-28 | 2020-01-30 | 華為技術有限公司Ｈｕａｗｅｉ Ｔｅｃｈｎｏｌｏｇｉｅｓ Ｃｏ．，Ｌｔｄ． | Transmitter optical subassembly, optical components, optical module and passive optical network system |
-
1988
- 1988-09-20 JP JP23703388A patent/JPH0283523A/en active Pending
Cited By (17)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US5398086A (en) * | 1991-03-20 | 1995-03-14 | Mitsubishi Denki Kabushiki Kaisha | Projection type display device |
| US5321448A (en) * | 1991-05-17 | 1994-06-14 | Casio Computer Co., Ltd. | Liquid crystal projector |
| US5631771A (en) * | 1991-09-19 | 1997-05-20 | Lucent Technologies Inc. | Optical isolator with polarization dispersion and differential transverse deflection correction |
| US6275323B1 (en) | 1992-07-31 | 2001-08-14 | Fujitsu Limited | Optical attenuator |
| US6018412A (en) * | 1992-07-31 | 2000-01-25 | Fujitsu Limited | Optical attenuator |
| US5889609A (en) * | 1992-07-31 | 1999-03-30 | Fujitsu Limited | Optical attenuator |
| US5539574A (en) * | 1994-12-21 | 1996-07-23 | At&T Corp. | Optical isolator with fabry-perot ripple reduction |
| US5812304A (en) * | 1995-08-29 | 1998-09-22 | Fujitsu Limited | Faraday rotator which generates a uniform magnetic field in a magnetic optical element |
| US5973821A (en) * | 1996-03-01 | 1999-10-26 | Fujitsu Limited | Variable optical attenuator which applies a magnetic field to a faraday element to rotate the polarization of light signal |
| US5867300A (en) * | 1996-03-01 | 1999-02-02 | Fujitsu Limited | Variable optical attenuator which applies a magnetic field to a faraday element to rotate the polarization of a light signal |
| US6333806B1 (en) | 1996-03-01 | 2001-12-25 | Fujitsu Limited | Variable optical attenuator which applies a magnetic field to a Faraday element to rotate the polarization of a light signal |
| US6570699B2 (en) | 1996-03-01 | 2003-05-27 | Fujitsu Limited | Variable optical attenuator which applies a magnetic field to a Faraday element to rotate the polarization of a light signal |
| US6717713B2 (en) | 1996-03-01 | 2004-04-06 | Fujitsu Limited | Variable optical attenuator which applies a magnetic field to a faraday element to rotate the polarization of a light signal |
| US5844710A (en) * | 1996-09-18 | 1998-12-01 | Fujitsu Limited | Faraday rotator and optical device employing the same |
| US6018411A (en) * | 1996-11-29 | 2000-01-25 | Fujitsu Limited | Optical device utilizing magneto-optical effect |
| JP2020503687A (en) * | 2016-12-28 | 2020-01-30 | 華為技術有限公司Ｈｕａｗｅｉ Ｔｅｃｈｎｏｌｏｇｉｅｓ Ｃｏ．，Ｌｔｄ． | Transmitter optical subassembly, optical components, optical module and passive optical network system |
| US11218221B2 (en) | 2016-12-28 | 2022-01-04 | Huawei Technologies Co., Ltd. | Transmitter optical subassembly, optical component, optical module, and passive optical network system |
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