JPS63304731A - Optical communication method - Google Patents
Optical communication methodInfo
- Publication number
- JPS63304731A JPS63304731A JP62139708A JP13970887A JPS63304731A JP S63304731 A JPS63304731 A JP S63304731A JP 62139708 A JP62139708 A JP 62139708A JP 13970887 A JP13970887 A JP 13970887A JP S63304731 A JPS63304731 A JP S63304731A
- Authority
- JP
- Japan
- Prior art keywords
- optical
- frequency
- node
- demultiplexer
- transmission
- 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 72
- 238000004891 communication Methods 0.000 title claims description 16
- 238000000034 method Methods 0.000 title claims description 7
- 230000005540 biological transmission Effects 0.000 claims abstract description 27
- 239000013307 optical fiber Substances 0.000 claims description 10
- 230000010355 oscillation Effects 0.000 claims 1
- 238000010586 diagram Methods 0.000 description 8
- 230000008878 coupling Effects 0.000 description 3
- 238000010168 coupling process Methods 0.000 description 3
- 238000005859 coupling reaction Methods 0.000 description 3
- VYPSYNLAJGMNEJ-UHFFFAOYSA-N Silicium dioxide Chemical compound O=[Si]=O VYPSYNLAJGMNEJ-UHFFFAOYSA-N 0.000 description 2
- 230000000694 effects Effects 0.000 description 2
- 238000005516 engineering process Methods 0.000 description 2
- 238000005452 bending Methods 0.000 description 1
- 239000003795 chemical substances by application Substances 0.000 description 1
- 230000006866 deterioration Effects 0.000 description 1
- 239000000835 fiber Substances 0.000 description 1
- WABPQHHGFIMREM-UHFFFAOYSA-N lead(0) Chemical compound [Pb] WABPQHHGFIMREM-UHFFFAOYSA-N 0.000 description 1
- 230000005855 radiation Effects 0.000 description 1
- 239000004065 semiconductor Substances 0.000 description 1
- 238000000926 separation method Methods 0.000 description 1
- 239000000377 silicon dioxide Substances 0.000 description 1
Landscapes
- Optical Communication System (AREA)
Abstract
Description
【発明の詳細な説明】
〔産業上の利用分野〕
本発明は、複数のノードが共通の光ファイバ伝送路を用
いて、/−ド間で通信を行なう光通信方式に関するもの
であって、特に同一伝送路に従来上り多数のノードを接
続することの可能な光バス形通信方式に係る。[Detailed Description of the Invention] [Field of Industrial Application] The present invention relates to an optical communication system in which a plurality of nodes communicate between nodes using a common optical fiber transmission path, and in particular, The present invention relates to an optical bus type communication system that can conventionally connect a large number of uplink nodes to the same transmission path.
光ファイバを使用したバス形通信方式は、動画、高速デ
ータ等広帯域の信号にユーザからアクセスする、広帯域
ユーザ・網インタフェースの実現法の一種として有用で
ある。A bus-type communication system using optical fibers is useful as a method for realizing a wideband user/network interface that allows users to access wideband signals such as moving images and high-speed data.
第1図は、従来の光バス形通信網の構成の例を示す図で
あって、1は光ファイバ伝送路、2は光方向性結合器、
3はノードを表わしている。FIG. 1 is a diagram showing an example of the configuration of a conventional optical bus type communication network, in which 1 is an optical fiber transmission line, 2 is an optical directional coupler,
3 represents a node.
同図に示すように、このような従来の構成においては、
光分岐・挿入器として光方向性結合器2を使用している
ため、光分岐・挿入器には信号の送り先に対する識別8
!能がないから、時分割された送信信号の先頭に送り先
の7ドレスをつけることにより、受信側で必要な信号か
どうかを区別していた。As shown in the figure, in such a conventional configuration,
Since the optical directional coupler 2 is used as an optical drop/adder, the optical drop/adder has an identification 8 for the destination of the signal.
! Therefore, by adding the 7 address of the destination to the beginning of the time-divided transmission signal, the receiving side could distinguish whether the signal was needed or not.
上述したような従来の光バス形通信網においては、送信
信号の先頭に送り先のアドレスを付けなければならない
という制御上の煩わしさがある上、さらに、光分岐・挿
入に際して光信号パワーの損失を生ずる欠点があった。In the conventional optical bus type communication network as described above, there is a control problem of having to add the destination address to the beginning of the transmitted signal, and furthermore, there is a need to add a destination address to the beginning of the transmitted signal. There were some drawbacks.
そのため、このバス形通信網に接続可能なメート数が制
約を受け、従来実用化されている光バス形通信方式で“
はノード数は高々10程度であった。Therefore, the number of meters that can be connected to this bus-type communication network is limited, and the optical bus-type communication method that has been put into practical use
The number of nodes was about 10 at most.
本発明は、このような従来の方式の欠点に鑑み、光分岐
・挿入器の損失によりノード数に制約を受けたり、ある
いは、送信信号にアドレスをつける必要のない光バス形
通信方式を提供することを目的としている。In view of the shortcomings of the conventional systems, the present invention provides an optical bus type communication system that is not limited in the number of nodes due to losses in optical drop/droppers or does not require addresses to be attached to transmission signals. The purpose is to
本発明によれば、上述の目的は、前記特許請求の範囲に
記載した手段により達成される。According to the invention, the above-mentioned object is achieved by the means specified in the claims.
すなわち、本発明は各信号を光周波数多重し、各ノード
での光分岐・挿入器として光合分波器を使用するもので
あって、光分岐・挿入器が原理的に無損失であること、
送信信号に送り先のアドレスを付ける必要のないこと等
の、αにおいて、従来の技術とは異なるものである。That is, the present invention optically frequency multiplexes each signal and uses an optical multiplexer/demultiplexer as an optical drop/adder at each node, and the optical drop/dropper is lossless in principle.
This method differs from the conventional technology in terms of α, such as the fact that there is no need to add a destination address to the transmitted signal.
12図は、本発明の一実施例の光バス形通信網の構成を
示す図であって、1は、第1図の場合と同様に光ファイ
バ伝送路を表わしており、41〜4nは光分岐器として
用いる光合分波器、5□〜5nは光挿入器として用いる
光合分波器、6、〜60はノードを表わしている。FIG. 12 is a diagram showing the configuration of an optical bus type communication network according to an embodiment of the present invention, in which 1 represents an optical fiber transmission line as in the case of FIG. 1, and 41 to 4n represent optical fiber transmission lines. Optical multiplexer/demultiplexers used as splitters, 5□ to 5n represent optical multiplexer/demultiplexers used as optical adders, and 6, to 60 represent nodes.
同図において、光分岐器4□〜4nは透過周波数を固定
した光合分波器であり、光挿入器51〜5nは透過周波
数が可変の光合分波器である。In the figure, optical splitters 4□-4n are optical multiplexers/demultiplexers with fixed transmission frequencies, and optical adders 51-5n are optical multiplexers/demultiplexers with variable transmission frequencies.
本実施例では、各ノードに一つずつ周波数(「il B
l fk )を割り当て、そのメートに属する分岐器
として用いる光合分波器の透過周波数をその値に固定す
る。メート間のアクセスは送り側の光源周波数と挿入器
として用いる光合分波器の透過周波数を同調する二とに
より可能である。In this embodiment, each node has one frequency (“il B
l fk ), and the transmission frequency of the optical multiplexer/demultiplexer used as a splitter belonging to that mate is fixed to that value. Access between the mats is possible by tuning the transmitting side light source frequency and the transmission frequency of the optical multiplexer/demultiplexer used as the inserter.
例えば、ノード62から61にアクセスするには、まず
ノード62の光合分波器52の透過周波数をfiに同調
し、/−ドロ1の光源周波数をfjにして送信する。ノ
ード61の光合分波器41は予めfiのみ透過するよう
に設定されており、ノード62から送信された周波数f
iの信号を選択的に受信することができる。For example, in order to access node 61 from node 62, first, the transmission frequency of optical multiplexer/demultiplexer 52 of node 62 is tuned to fi, and the light source frequency of /-doro 1 is set to fj and transmitted. The optical multiplexer/demultiplexer 41 of the node 61 is set in advance to transmit only fi, and the frequency f transmitted from the node 62
i signals can be selectively received.
半導体レーザを光源とした場合、光源周波数の同調は温
度やバイアス電流を変化させることにより可能である6
第3図は、光分岐・挿入器用光合分波器として用いる光
導波路形の二重リング共振器形チャネル分波器の構成の
例を示す図であって、7は光導波路、81,8□はリン
グ形光導波路、9は熱電極、10はリード線、11は光
方向性結合器を表わしている。When a semiconductor laser is used as a light source, tuning of the light source frequency is possible by changing the temperature and bias current.6 Figure 3 shows the double ring resonance of an optical waveguide used as an optical multiplexer/demultiplexer for an optical branch/adder. It is a diagram showing an example of the configuration of a vessel-shaped channel splitter, in which 7 is an optical waveguide, 81 and 8□ are ring-shaped optical waveguides, 9 is a thermal electrode, 10 is a lead wire, and 11 is an optical directional coupler. It represents.
本二重すング形チャネル分波器では、リング導波路の直
径が互いに異なっており、また共振周波数間隔は各々の
リングの共振周波数間隔の最小公倍数となる。In this double ring type channel splitter, the diameters of the ring waveguides are different from each other, and the resonant frequency interval is the least common multiple of the resonant frequency intervals of each ring.
また、共振周波数の周期は導波路の伝搬定数(等価屈折
率)を変化することにより可能であり、実際には第3図
に示すように導波路上に熱変調、あるいは電気光学効果
による変調等を行なうための電極を設定することにより
実現できる。In addition, the period of the resonant frequency can be changed by changing the propagation constant (equivalent refractive index) of the waveguide, and in reality, as shown in Figure 3, thermal modulation or modulation due to electro-optic effect is applied to the waveguide. This can be achieved by setting electrodes for this purpose.
第4図は、第3図に示した二重リング共振器形チャネル
分波器の透過損失の周波数依存性を模式的に示したもの
である。FIG. 4 schematically shows the frequency dependence of the transmission loss of the double ring resonator type channel demultiplexer shown in FIG.
透過損失は一定の周波数間隔ΔFで繰り返し零となる。The transmission loss repeatedly becomes zero at constant frequency intervals ΔF.
従って、周波数多重を行なうために使用可能な周波数帯
域は最大ΔFとなる。Therefore, the maximum frequency band available for frequency multiplexing is ΔF.
また、低透過損失領域の幅をΔfとすれば周波数多重可
能なチャネル数NはN=ΔF/Δfとなる。Further, if the width of the low transmission loss region is Δf, the number N of channels that can be frequency multiplexed is N=ΔF/Δf.
第5図はΔF=40GHzで設計した二重リング共振器
形チャネル分波器の透過損失の周波数依存性の計算例を
示したものである。FIG. 5 shows an example of calculating the frequency dependence of the transmission loss of a double ring resonator channel duplexer designed with ΔF=40 GHz.
本計算例では、屈折率1.46の石英系光導波路を仮定
しており、リング導波路の半径は各々5736.8μ輪
、6556.3μm、各々のリング導波路と入出力光導
波路の電力結合係数に1は0.12、 リング導波路間
の電力結合係数に2は0.006である。In this calculation example, a silica-based optical waveguide with a refractive index of 1.46 is assumed, and the radius of the ring waveguide is 5736.8 μm and 6556.3 μm, respectively, and the power coupling between each ring waveguide and input/output optical waveguide is The coefficient 1 is 0.12, and the power coupling coefficient between the ring waveguides 2 is 0.006.
本計算例では、クロストークの最悪値は、−14dBで
あり、クロストークによる劣化は、殆ど生じないものと
考えられる。In this calculation example, the worst value of crosstalk is -14 dB, and it is considered that almost no deterioration due to crosstalk occurs.
また、3dB透過帯域幅Δfは 190MHzであり、
周波数多重可能なチャネル数は210となる。Also, the 3dB transmission bandwidth Δf is 190MHz,
The number of channels that can be frequency multiplexed is 210.
このことは、従来の光バス方式と比較して、ノード数が
20倍以上となることを示している。This indicates that the number of nodes is 20 times or more compared to the conventional optical bus system.
また、本質的には光分岐・挿入器による損失の増加はな
く、/−ド数の制限要因とはならない。In addition, there is essentially no increase in loss due to the optical drop/adder, and it does not become a limiting factor for the number of /- codes.
一方、可同調形の光合分波器は、波長分離4子として可
動形の回折格子を使用したり、−重リング共振器により
構成することができる。しかし、回折格子を用いた光合
分波器ではチャネル数が光ファイバと回折格子との結合
損失で制限され、現在までに実現されたものは、最大2
0チャネル程度である。On the other hand, a tunable optical multiplexer/demultiplexer can use a movable diffraction grating as a wavelength separation quadruplet, or can be configured with a double ring resonator. However, in optical multiplexers/demultiplexers using diffraction gratings, the number of channels is limited by the coupling loss between the optical fiber and the diffraction grating, and the ones realized to date have a maximum of 2 channels.
There are approximately 0 channels.
また、−重リング共振器で、上記二重リング共振器と同
一のΔFを有するものを作製するためには、リングの半
径を約半分にする必要があり、導波路の曲がりによる放
射損失が者しく増加する可能性がある。そのため、−重
リング共振器の場合も、チャネル数を多くとることが難
しい。In addition, in order to fabricate a double ring resonator with the same ΔF as the double ring resonator described above, the radius of the ring must be approximately halved, and radiation loss due to bending of the waveguide will be reduced. There is a possibility that it will increase significantly. Therefore, it is difficult to increase the number of channels even in the case of a double ring resonator.
従って、本発明の分岐・挿入器用光合分波器は、第3図
に示したような光導波路二重リング共振器を用いること
が望ましい。Therefore, it is desirable that the optical multiplexer/demultiplexer for a drop/adder according to the present invention uses an optical waveguide double ring resonator as shown in FIG.
以上説明したように、本方式ではノードのアドレスを光
周波数に対応させろので送(i信号に送り先の7ドレス
をつける必要がないこと、また二重リング共振話形チャ
ネル分波器を分岐挿入器として使用することにより、挟
間波数間隔で整列した多数の光周波数を原理的には無損
失で選択的に透過することができ、多数のノードを接続
できること等の利点がある。As explained above, in this method, since the address of the node corresponds to the optical frequency, there is no need to add the 7 addresses of the destination to the i signal. By using the optical fiber as an optical fiber, it is possible in principle to selectively transmit a large number of optical frequencies arranged at narrow wave number intervals without loss, and there are advantages such as being able to connect a large number of nodes.
m1図は従来の光バス形通信網の構成の例を示す図、第
2図は本発明の一実施例の光バス形通信網の構成を示す
図、第3図は二重リング共振話形チャネル分波器の構成
の例を示す図、第4図は二重リング共振話形チャネル分
波器の透過特性の模式図、15図は二重リング共振話形
チャネル分波器の透過特性の計算結果を示す図である。
1 ・・・・・・光7フイバ伝送路、 2.11・
・・・・・光方向性結合器、 3.61〜6n ・
・・・・・ ノード、 41〜4n・・・・・・
光分岐器、5、〜5 ++・・・・・・光挿入器、
7 ・・・・・・光導波路、 8・・・・・・ リ
ング形光導波路、 9 ・・・・・・ 熱電極、
10 ・・・・・・ リード線代理人 弁理士
本 間 崇第1図
第2図
第 3 図Figure m1 is a diagram showing an example of the configuration of a conventional optical bus type communication network, Figure 2 is a diagram showing the configuration of an optical bus type communication network according to an embodiment of the present invention, and Figure 3 is a double ring resonant type communication network. A diagram showing an example of the configuration of a channel duplexer, Figure 4 is a schematic diagram of the transmission characteristics of a double ring resonant spoken channel duplexer, and Figure 15 is a schematic diagram of the transmission characteristics of a double ring resonant spoken channel duplexer. It is a figure showing a calculation result. 1...Optical 7 fiber transmission line, 2.11.
...Optical directional coupler, 3.61~6n ・
・・・・・・ Node, 41~4n・・・・・・
Optical splitter, 5, ~5 ++... Optical adder,
7... Optical waveguide, 8... Ring-shaped optical waveguide, 9... Thermal electrode,
10 ・・・・・・Lead line agent Patent attorney
Takashi Honma Figure 1 Figure 2 Figure 3
Claims (2)
号を取り込み、あるいは、光信号を送出するための光分
岐・挿入器と、発振光周波数可変の複数の光源とを具備
する複数のノードを有し、各ノード間で通信を行なうバ
ス形通信網において、光分岐・挿入器として光合分波器
を使用するとともに、各ノードごとに固有の少なくとも
一つの光周波数を割り当てることを特徴とする光通信方
式。(1) A plurality of nodes equipped with an optical fiber transmission line, an optical branch/adder for taking in an optical signal on the optical fiber transmission line or sending out an optical signal, and a plurality of light sources whose oscillation optical frequency is variable. In a bus-type communication network that communicates between nodes, an optical multiplexer/demultiplexer is used as an optical branch/adder, and at least one unique optical frequency is assigned to each node. Optical communication method.
振器形チャネル分波器を使用する特許請求の範囲第(1
)項記載の光通信方式。(2) Claim No. 1 which uses a double ring resonator type channel demultiplexer as an optical multiplexer/demultiplexer for an optical branch/adder.
Optical communication method described in ).
Priority Applications (1)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
JP62139708A JPS63304731A (en) | 1987-06-05 | 1987-06-05 | Optical communication method |
Applications Claiming Priority (1)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
JP62139708A JPS63304731A (en) | 1987-06-05 | 1987-06-05 | Optical communication method |
Publications (1)
Publication Number | Publication Date |
---|---|
JPS63304731A true JPS63304731A (en) | 1988-12-13 |
Family
ID=15251570
Family Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
JP62139708A Pending JPS63304731A (en) | 1987-06-05 | 1987-06-05 | Optical communication method |
Country Status (1)
Country | Link |
---|---|
JP (1) | JPS63304731A (en) |
Cited By (2)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
JPH04369130A (en) * | 1991-06-17 | 1992-12-21 | Nippon Telegr & Teleph Corp <Ntt> | Optical wavelength multiplex communication system |
US6081357A (en) * | 1996-07-19 | 2000-06-27 | Nec Corporation | Optical communication network system with wavelength-based signal distribution |
Citations (2)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
JPS56114457A (en) * | 1980-02-12 | 1981-09-09 | Toshiba Corp | Wavelength-multiplex ring bus system |
JPS62100706A (en) * | 1985-10-28 | 1987-05-11 | Nippon Telegr & Teleph Corp <Ntt> | Optical ring filter |
-
1987
- 1987-06-05 JP JP62139708A patent/JPS63304731A/en active Pending
Patent Citations (2)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
JPS56114457A (en) * | 1980-02-12 | 1981-09-09 | Toshiba Corp | Wavelength-multiplex ring bus system |
JPS62100706A (en) * | 1985-10-28 | 1987-05-11 | Nippon Telegr & Teleph Corp <Ntt> | Optical ring filter |
Cited By (2)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
JPH04369130A (en) * | 1991-06-17 | 1992-12-21 | Nippon Telegr & Teleph Corp <Ntt> | Optical wavelength multiplex communication system |
US6081357A (en) * | 1996-07-19 | 2000-06-27 | Nec Corporation | Optical communication network system with wavelength-based signal distribution |
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