JPH0690366B2 - Grating type optical demultiplexer - Google Patents
Grating type optical demultiplexerInfo
- Publication number
- JPH0690366B2 JPH0690366B2 JP4331286A JP4331286A JPH0690366B2 JP H0690366 B2 JPH0690366 B2 JP H0690366B2 JP 4331286 A JP4331286 A JP 4331286A JP 4331286 A JP4331286 A JP 4331286A JP H0690366 B2 JPH0690366 B2 JP H0690366B2
- Authority
- JP
- Japan
- Prior art keywords
- polarization
- diffraction grating
- optical demultiplexer
- optical
- polarization separation
- 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 - Fee Related
Links
Classifications
-
- 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
- G02B6/26—Optical coupling means
- G02B6/28—Optical coupling means having data bus means, i.e. plural waveguides interconnected and providing an inherently bidirectional system by mixing and splitting signals
- G02B6/293—Optical coupling means having data bus means, i.e. plural waveguides interconnected and providing an inherently bidirectional system by mixing and splitting signals with wavelength selective means
- G02B6/29304—Optical coupling means having data bus means, i.e. plural waveguides interconnected and providing an inherently bidirectional system by mixing and splitting signals with wavelength selective means operating by diffraction, e.g. grating
- G02B6/29305—Optical coupling means having data bus means, i.e. plural waveguides interconnected and providing an inherently bidirectional system by mixing and splitting signals with wavelength selective means operating by diffraction, e.g. grating as bulk element, i.e. free space arrangement external to a light guide
- G02B6/29307—Optical coupling means having data bus means, i.e. plural waveguides interconnected and providing an inherently bidirectional system by mixing and splitting signals with wavelength selective means operating by diffraction, e.g. grating as bulk element, i.e. free space arrangement external to a light guide components assembled in or forming a solid transparent unitary block, e.g. for facilitating component alignment
-
- 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
- G02B6/26—Optical coupling means
- G02B6/28—Optical coupling means having data bus means, i.e. plural waveguides interconnected and providing an inherently bidirectional system by mixing and splitting signals
- G02B6/293—Optical coupling means having data bus means, i.e. plural waveguides interconnected and providing an inherently bidirectional system by mixing and splitting signals with wavelength selective means
- G02B6/29371—Optical coupling means having data bus means, i.e. plural waveguides interconnected and providing an inherently bidirectional system by mixing and splitting signals with wavelength selective means operating principle based on material dispersion
- G02B6/29373—Optical coupling means having data bus means, i.e. plural waveguides interconnected and providing an inherently bidirectional system by mixing and splitting signals with wavelength selective means operating principle based on material dispersion utilising a bulk dispersive element, e.g. prism
-
- 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
- G02B6/26—Optical coupling means
- G02B6/28—Optical coupling means having data bus means, i.e. plural waveguides interconnected and providing an inherently bidirectional system by mixing and splitting signals
- G02B6/293—Optical coupling means having data bus means, i.e. plural waveguides interconnected and providing an inherently bidirectional system by mixing and splitting signals with wavelength selective means
- G02B6/29379—Optical coupling means having data bus means, i.e. plural waveguides interconnected and providing an inherently bidirectional system by mixing and splitting signals with wavelength selective means characterised by the function or use of the complete device
- G02B6/2938—Optical coupling means having data bus means, i.e. plural waveguides interconnected and providing an inherently bidirectional system by mixing and splitting signals with wavelength selective means characterised by the function or use of the complete device for multiplexing or demultiplexing, i.e. combining or separating wavelengths, e.g. 1xN, NxM
Landscapes
- Physics & Mathematics (AREA)
- General Physics & Mathematics (AREA)
- Optics & Photonics (AREA)
- Chemical & Material Sciences (AREA)
- Dispersion Chemistry (AREA)
Description
【発明の詳細な説明】 〔概要〕 本発明は回折格子と偏光分離素子を含む光分波器で、偏
光分離素子から回折格子までの各偏光の光路長を等し、
回折格子の偏光依存性を低減させ、光分波器の効率を上
げた。DETAILED DESCRIPTION OF THE INVENTION [Outline] The present invention is an optical demultiplexer including a diffraction grating and a polarization splitting element, in which the optical path length of each polarization from the polarization splitting element to the diffraction grating is equalized,
The polarization dependence of the diffraction grating is reduced and the efficiency of the optical demultiplexer is increased.
本発明は回折格子により多波長の光を一度に波長別に分
解する回折格子型光分波器に関するものである。The present invention relates to a diffraction grating type optical demultiplexer that decomposes light of multiple wavelengths into wavelengths at once by a diffraction grating.
将来の超大容量光通信を行うための手段として波長の多
重化がある。この目的の合成波器としては、波長分解能
と多チャンネル化に有利である回折格子を用いる方法が
適している。しかし、回折格子の効率には偏光依存性が
あるため、ファイバ伝送路からの光を受ける分波器では
挿入損失の増加、変動が生じることが考えられる。この
ような光波長多重通信においては分波器の偏光依存性を
除去する構成を必要としている。Wavelength multiplexing is a means for performing future ultra-high capacity optical communication. As a synthetic wave device for this purpose, a method using a diffraction grating, which is advantageous for wavelength resolution and multichannel, is suitable. However, since the efficiency of the diffraction grating depends on the polarization, it is considered that the insertion loss increases or changes in the demultiplexer that receives the light from the fiber transmission line. In such optical wavelength division multiplexing communication, it is necessary to have a configuration for removing the polarization dependence of the demultiplexer.
第３図、第４図に「特開昭58−82220号公報」に開示さ
れている従来の分波器を示す。3 and 4 show a conventional duplexer disclosed in Japanese Patent Laid-Open No. 58-82220.
図において、１は入力用光ファイバ、２は出力用光ファ
イバ、３は集光用レンズ、４は光分波器、５は反射型の
回折格子、６はガラス等の透明材からなる三角柱形状の
透明体、７は透明体６の斜面に形成された偏光分離膜、
８は断面が平行四辺形の四角錐形状からなるガラス等の
透明体、９は1/2波長板である。In the figure, 1 is an input optical fiber, 2 is an output optical fiber, 3 is a condenser lens, 4 is an optical demultiplexer, 5 is a reflection type diffraction grating, and 6 is a triangular prism shape made of a transparent material such as glass. , A polarized light separation film 7 formed on the slope of the transparent body 6,
Reference numeral 8 is a transparent body such as glass having a quadrangular pyramid shape whose cross section is a parallelogram, and 9 is a half-wave plate.
従来の光分波器４は入出力用の光ファイバ1,2間の光路
上に、透明体6,8と波長板９を組合せた偏光変換部と、
紙面に対し垂直方向に形成された多数の溝5aを有する回
折格子５を図示状態に配置して構成されていた。The conventional optical demultiplexer 4 has a polarization conversion section in which transparent bodies 6 and 8 and a wavelength plate 9 are combined on the optical path between the input and output optical fibers 1 and 2.
The diffraction grating 5 having a large number of grooves 5a formed in the direction perpendicular to the paper surface is arranged in the illustrated state.
また、光分波機能は光ファイバ１より出射されたλ1，
λ2，λ3，λ4の多波長の入射光ａがレンズ３を透過し
て平行光になり、それが光分波器４に入射し、該光分波
器４では上記偏光変換部による偏光分離作用（最大の回
折効率を得るための機能）と回折格子５による波長分離
作用（各波長毎に異なる回折角度の回折光を得るための
機能）により該入射光ａの各波長を一度に分波し且つ出
射せしめ、それによってλ1，λ2，λ3，λ4の波長別に
分離された出射光ｂ（λ4のみ図示）が再びレンズ３を
透過して夫々の光ファイバ２へ集光されることで果され
る。In addition, the optical demultiplexing function is λ 1 emitted from the optical fiber 1 ,
Incident light a of multiple wavelengths of λ 2 , λ 3 , and λ 4 is transmitted through the lens 3 to become parallel light, which is incident on the optical demultiplexer 4 and the optical demultiplexer 4 uses the polarization conversion unit. Each wavelength of the incident light “a” is treated at once by the polarization separation action (function for obtaining maximum diffraction efficiency) and the wavelength separation action by the diffraction grating 5 (function for obtaining diffracted light of different diffraction angle for each wavelength). The output light b (only λ 4 is shown) separated by the wavelengths λ 1 , λ 2 , λ 3 , and λ 4 again passes through the lens 3 and is collected into the respective optical fibers 2. It is achieved by being illuminated.
このような光分波器４においては、入射光ａは偏光分離
膜７で回折格子５の溝5aに垂直な偏光成分Ｐと平行な偏
光成分Ｓとし分離され、溝5aに平行な成分Ｓに対しては
波長板９により偏向面が90°回転されて、両成分P,Sと
も回折効率の高い垂直成分として回折格子５に互に平行
な状態で入射する。In such an optical demultiplexer 4, the incident light a is separated by the polarization separation film 7 into a polarization component S parallel to the polarization component P perpendicular to the groove 5a of the diffraction grating 5 and divided into a component S parallel to the groove 5a. On the other hand, the deflecting surface is rotated by 90 ° by the wave plate 9, and both components P and S are incident on the diffraction grating 5 in parallel with each other as vertical components having high diffraction efficiency.
また回析格子５による回折光は理想的にはほぼ逆の経路
をだとり、偏光分離膜７で合成され出射光ｂとなる。Ideally, the diffracted light from the diffraction grating 5 takes an almost opposite path, and is combined by the polarization separation film 7 to be emitted light b.
ところで、従来の光分波器４では偏光分離膜７から回折
格子５までの各偏光成分P,Sの光路長が異なるため、第
４図に示す如くＳ偏光回折光ｃとｐ偏光回折光ｄでは位
置ずれ（Δ）を生じ完全に合成されず、挿入損失が大き
くなる欠点があった。By the way, in the conventional optical demultiplexer 4, since the optical path lengths of the respective polarization components P and S from the polarization splitting film 7 to the diffraction grating 5 are different, as shown in FIG. However, there is a drawback that a positional shift (Δ) occurs and the components are not completely combined, resulting in a large insertion loss.
本発明は上記欠点を解決するために、偏光分離素子から
回折格子までの各偏光の光路長をほぼ等しく構成した回
折格子形光分波器を提供した。In order to solve the above-mentioned drawbacks, the present invention provides a diffraction grating type optical demultiplexer in which the optical path length of each polarized light from the polarization separation element to the diffraction grating is made substantially equal.
この構成によれば光路長が等しくなっているため、各偏
光回折光はほぼ完全に入射時の偏光経路るたどり偏光分
離膜での合成が果される。According to this configuration, since the optical path lengths are the same, each polarized diffracted light traces the polarization path at the time of incidence almost completely and is synthesized by the polarization separation film.
第１図は本発明に係る回折格子型光分波器を示す側断面
図である。FIG. 1 is a side sectional view showing a diffraction grating type optical demultiplexer according to the present invention.
図において、10は光分波器、11は反射型の回折格子、12
は三角柱形状のガラス等からなる透明体、13は平行四辺
形断面の四角錐形状からなるガラス等の透明体、14は三
角柱形状のガラス等からなる透明体、15は透明体12の斜
面に形成された例えばSi（ｎ＝3.65）とSiO2（ｎ＝1.4
5）の交互に積層した７層構成の誘電体多層膜よりなる
偏光分離膜、16は1/2波長板、ａは入射光、ｂは出射
光、ｃはＳ偏光回折光、ｄはｐ偏光回折光である。In the figure, 10 is an optical demultiplexer, 11 is a reflection type diffraction grating, and 12
Is a transparent body made of triangular prism-shaped glass, 13 is a transparent body made of glass having a quadrangular pyramid shape with a parallelogram cross section, 14 is a transparent body made of triangular prism-shaped glass, etc., and 15 is formed on the slope of the transparent body 12. For example, Si (n = 3.65) and SiO 2 (n = 1.4)
5) Polarization separation film consisting of 7-layered dielectric multilayer film alternately laminated, 16 is a half-wave plate, a is incident light, b is outgoing light, c is S-polarized diffracted light, and d is p-polarized light. It is diffracted light.
本光分波器10も従来と同様、入出力用の光ファイバ1,2
間の光路上に集光レンズ３と共に配置され波長分波の機
能を果す。The optical demultiplexer 10 is also the same as the conventional optical fiber for input and output 1, 2
It is arranged together with the condenser lens 3 on the optical path between them to fulfill the function of wavelength demultiplexing.
本光分波器10はQ1が約30°、Q2が約60°の直角三角柱か
らなる透明体12,14と四角錐の透明体13および波長板16
を組合せて透明接着剤にて固定し、回折格子11はその溝
11a側を透明体14の外面に透明接着剤にて固定して構成
されている。また、偏光分離膜15への入射光ａの入射角
度Q3は回折格子11への各偏光成分P,Sの入射角度による
光路差と打ち消し合うように決められており、約60°に
設定されている。The optical demultiplexer 10 has a transparent body 12 and a transparent body 12 having a quadrangular pyramid 13 and a wave plate 16 each having a right-angled triangular prism with Q 1 of about 30 ° and Q 2 of about 60 °.
Fixed with a transparent adhesive, and the diffraction grating 11 is
The side of 11a is fixed to the outer surface of the transparent body 14 with a transparent adhesive. The incident angle Q 3 of the incident light a on the polarization separation film 15 is determined so as to cancel out the optical path difference due to the incident angle of each polarization component P, S on the diffraction grating 11, and is set to about 60 °. ing.
この構成により本光分波器10は偏光分離膜15から回折格
子11までの各偏光の光路長を等しく設定できる。With this configuration, the optical demultiplexer 10 can set the optical path length of each polarization from the polarization separation film 15 to the diffraction grating 11 to be equal.
第２図は本発明に係る光分波器10の入射偏光依存性を示
す実験データで、縦軸は挿失変動を横軸はｐ偏光強度／
入射光強度を示す。FIG. 2 is experimental data showing the incident polarization dependence of the optical demultiplexer 10 according to the present invention, in which the vertical axis represents insertion loss fluctuation and the horizontal axis represents p polarization intensity /
Indicates the incident light intensity.
この実験では、回折格子11として溝11aが600本/mmで1.5
5μｍ周期のものを使用し、分波器構成としては第１図
で説明のものを使用した。また入力用光ファイバとして
シングルモードを、出力用光ファイバはマルチモードフ
ァイバを使用して各ファイバをアレイ状（ファイバ間隔
は12.5μｍ）に並べたものを用い、集光レンズとしては
集点距離ｆ＝22.4mmの平凸レンズを使用した。In this experiment, the number of grooves 11a as the diffraction grating 11 is 600 / mm and 1.5
A 5 μm cycle was used, and the demultiplexer configuration used was that described in FIG. Also, a single mode is used as the input optical fiber, a multimode fiber is used as the output optical fiber, and the fibers are arranged in an array (fiber spacing is 12.5 μm). A plano-convex lens of 22.4 mm was used.
この結果、挿入損失が2.0dBで、第２図の線Ａの如く損
失変動が0.1dBの偏光依存性のほとんどない、光分波器
が得られた。As a result, an optical demultiplexer having an insertion loss of 2.0 dB and a loss variation of 0.1 dB with almost no polarization dependence as shown by line A in FIG. 2 was obtained.
また波長可変光源を用いて隣接ファイバ間のクロストー
クと各波長の透過帯域を測定した結果、透過帯域幅が約
6mm、クロストークが約−20dBの良好な特性が得られ
た。In addition, as a result of measuring the crosstalk between adjacent fibers and the transmission band of each wavelength using a tunable light source, the transmission bandwidth is about
Good characteristics of 6 mm and crosstalk of about -20 dB were obtained.
以上の本発明によれば、偏光依存性のほとんどない光分
波器が得られ、その実用上の効果は著しいものである。According to the present invention described above, an optical demultiplexer having almost no polarization dependence can be obtained, and its practical effect is remarkable.
第１図は本発明に係る光分波器の実施例図、第２図は本
発明による光合波器の偏光依存性を示す実験データ、第
３図と第４図は従来の光分波器の説明図である。 〔符号の説明〕 10…光分波器、15…偏光分離膜 11…回折格子、16…1/2波長板 12,13,14…透明体FIG. 1 is an embodiment diagram of an optical demultiplexer according to the present invention, FIG. 2 is experimental data showing polarization dependence of an optical multiplexer according to the present invention, and FIGS. 3 and 4 are conventional optical demultiplexers. FIG. [Explanation of symbols] 10 ... Optical demultiplexer, 15 ... Polarization separation film 11 ... Diffraction grating, 16 ... 1/2 wave plate 12, 13, 14 ... Transparent body
Claims (3)
で構成され、入射光が該偏光分離素子により偏光分離さ
れて各偏光成分が前記回折格子に対し最大の回折効率に
なるよう入射する回折格子型光分波器であって、 前記偏光分離素子から前記回折格子までの各偏光の光路
長が等しくなるように構成されていることを特徴とした
回折格子型光分波器。1. A diffraction grating including at least a diffraction grating and a polarization separation element, wherein incident light is polarized and separated by the polarization separation element and each polarization component is incident on the diffraction grating so as to have maximum diffraction efficiency. Grating type optical demultiplexer, wherein the optical path length of each polarization from the polarization separation element to the diffraction grating is equal.
回転させる波長板が挿入されており、前記偏光分離素子
により偏光分離された各偏光成分が前記回折格子の溝方
向に対し垂直な偏光成分になるに構成されていることを
特徴とした特許請求の範囲第１項記載の回折格子型光分
波器。2. A wavelength plate for rotating the polarization plane is inserted in one of the polarization optical paths, and each polarization component polarized and separated by the polarization separation element is perpendicular to the groove direction of the diffraction grating. The diffraction grating type optical demultiplexer according to claim 1, wherein the optical demultiplexer has a different polarization component.
され、該偏光分離膜への前記入射光の入射角度を60°と
したことを特徴とする特許請求の範囲第１項記載の回折
格子型光分波器。3. The diffraction grating according to claim 1, wherein the polarization separation element is formed of a dielectric multilayer film, and an incident angle of the incident light on the polarization separation film is 60 °. Lattice type optical demultiplexer.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP4331286A JPH0690366B2 (en) | 1986-02-28 | 1986-02-28 | Grating type optical demultiplexer |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP4331286A JPH0690366B2 (en) | 1986-02-28 | 1986-02-28 | Grating type optical demultiplexer |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JPS62200320A JPS62200320A (en) | 1987-09-04 |
| JPH0690366B2 true JPH0690366B2 (en) | 1994-11-14 |
Family
ID=12660283
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP4331286A Expired - Fee Related JPH0690366B2 (en) | 1986-02-28 | 1986-02-28 | Grating type optical demultiplexer |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JPH0690366B2 (en) |
Families Citing this family (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US6014254A (en) * | 1997-02-24 | 2000-01-11 | Cheng; Yihao | Optical device for splitting an input beam into two orthogonal polarization states |
| US6859317B1 (en) * | 2000-06-02 | 2005-02-22 | Confluent Photonics Corporation | Diffraction grating for wavelength division multiplexing/demultiplexing devices |
| JP4374774B2 (en) * | 2000-12-06 | 2009-12-02 | コニカミノルタホールディングス株式会社 | Polarization conversion optical system and polarization conversion element |
-
1986
- 1986-02-28 JP JP4331286A patent/JPH0690366B2/en not_active Expired - Fee Related
Also Published As
| Publication number | Publication date |
|---|---|
| JPS62200320A (en) | 1987-09-04 |
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| LAPS | Cancellation because of no payment of annual fees |