JPS6318901B2 - - Google Patents
Info
- Publication number
- JPS6318901B2 JPS6318901B2 JP55074472A JP7447280A JPS6318901B2 JP S6318901 B2 JPS6318901 B2 JP S6318901B2 JP 55074472 A JP55074472 A JP 55074472A JP 7447280 A JP7447280 A JP 7447280A JP S6318901 B2 JPS6318901 B2 JP S6318901B2
- Authority
- JP
- Japan
- Prior art keywords
- optical
- wavelength
- transmission
- demultiplexer
- emission wavelength
- 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
Links
- 230000003287 optical effect Effects 0.000 claims description 121
- 230000005540 biological transmission Effects 0.000 claims description 56
- 238000010586 diagram Methods 0.000 description 5
- 238000000034 method Methods 0.000 description 5
- 230000003595 spectral effect Effects 0.000 description 3
- 230000002457 bidirectional effect Effects 0.000 description 2
- 230000006866 deterioration Effects 0.000 description 2
- 230000035945 sensitivity Effects 0.000 description 1
Classifications
-
- H—ELECTRICITY
- H04—ELECTRIC COMMUNICATION TECHNIQUE
- H04B—TRANSMISSION
- H04B10/00—Transmission systems employing electromagnetic waves other than radio-waves, e.g. infrared, visible or ultraviolet light, or employing corpuscular radiation, e.g. quantum communication
- H04B10/25—Arrangements specific to fibre transmission
- H04B10/2589—Bidirectional transmission
Landscapes
- Physics & Mathematics (AREA)
- Electromagnetism (AREA)
- Engineering & Computer Science (AREA)
- Computer Networks & Wireless Communication (AREA)
- Signal Processing (AREA)
- Optical Communication System (AREA)
Description
【発明の詳細な説明】
本発明は光通信システム、特に光多重伝送シス
テムに関するものである。DETAILED DESCRIPTION OF THE INVENTION The present invention relates to optical communication systems, and particularly to optical multiplex transmission systems.
近年、光通信システムの進歩は著しく、その用
途は各種の分野に広がりつつある。そしてその発
展形態の一つに単一の光伝送路を使用して一方向
ないしは双方向に同時に複数の光信号を伝送する
光多重伝送システムがある。 In recent years, optical communication systems have made remarkable progress, and their applications are expanding to various fields. One of its advanced forms is an optical multiplex transmission system that simultaneously transmits a plurality of optical signals in one or both directions using a single optical transmission path.
従来この種の光多重伝送方式としては、異なる
発光波長の光源と光分波器を組合せて、波長分割
により多重伝送を行なう波長分割多重伝送方式
と、送受信の多重分離に光方向性結合器を使用し
て、その方向性を利用し伝送方向の違いのみで送
信光信号と受信光信号を分離する双方向多重伝送
方式とが考えられている。前者の波長分割多重伝
送方式では長距離の伝送が可能であるが、反面発
光波長の異なる複数種の光源を準備しなければな
らない欠点がある。一方後者の方式は簡単ではあ
るが光伝送路での後方散乱や光コネクタなどの端
面での反射などにより、送信光信号が自局の光受
信器に廻り込んで千渉し、光受信感度を劣化させ
る為、ごく短距離の伝送しか使用できない欠点が
ある。そこで新しい方式として、例えば特願昭54
−104671号明細書に述べられているように同じ発
光波長域の光源を使用してその出力光を例えば長
波長成分と短波長成分にほぼ二等分し、互いに異
なる一方の波長成分のみを光伝送路に送出するこ
とにより、実質的に波長分割多重伝送を行なう方
式が提案されている。 Conventional optical multiplexing transmission systems of this type include wavelength division multiplexing transmission systems that perform multiplex transmission by wavelength division by combining light sources with different emission wavelengths and optical demultiplexers, and optical directional couplers for multiplexing and demultiplexing transmission and reception. A bidirectional multiplex transmission system is being considered in which the directivity is used to separate the transmitted optical signal and the received optical signal based only on the difference in transmission direction. The former wavelength division multiplexing transmission method allows long-distance transmission, but has the disadvantage of requiring the preparation of multiple types of light sources with different emission wavelengths. On the other hand, the latter method is simple, but due to backscattering in the optical transmission line and reflection at the end face of an optical connector, the transmitted optical signal wraps around and crosses the optical receiver of the own station, reducing the optical reception sensitivity. It has the disadvantage that it can only be used for very short distance transmission due to deterioration. Therefore, as a new method, for example,
- As described in Specification No. 104671, a light source with the same emission wavelength range is used, and the output light is divided into approximately two parts, for example, a long wavelength component and a short wavelength component, and only one wavelength component that is different from each other is emitted. A method has been proposed that essentially performs wavelength division multiplexing transmission by transmitting signals to a transmission path.
しかし、この方式にも一般には次のような問題
がある。すなわち発光波長のバラツキや温度によ
る発光波長の変化などによつて発光波長域が変わ
ると、光源の光出力電力が一定であつても実際に
光受信器まで伝送される所定波長の成分の光電力
はかなり変化するので、その変化分だけ余裕をみ
て伝送距離を短かくしておかなければならないと
いう問題である。 However, this method also generally has the following problems. In other words, if the emission wavelength range changes due to variations in emission wavelength or changes in emission wavelength due to temperature, even if the optical output power of the light source is constant, the optical power of the component of a given wavelength that is actually transmitted to the optical receiver will decrease. changes considerably, so the problem is that the transmission distance must be shortened to account for the change.
そこで本発明の目的はこのような欠点をなく
し、同じ発光波長域の光源を使用して、比較的長
距離の多重伝送が可能で、かつ温度などによる発
光波長域の変化に対してもかなり安定な光多重伝
送システムを提供することにある。 Therefore, the purpose of the present invention is to eliminate these drawbacks, to make relatively long-distance multiplex transmission possible using light sources with the same emission wavelength range, and to be fairly stable against changes in the emission wavelength range due to temperature, etc. The purpose of this invention is to provide an optical multiplex transmission system.
本発明によれば実質的に同じ発光波長域を持つ
光源を使用した２台の光送信器と、２台の光受信
器とが光分波器を介して単一の光伝送路の両端に
光学的に接続されていて、前記単一の光伝送路を
使用して多重伝送を行なう光多重伝送システムに
おいて、前記２台の光送信器がその光源の発光波
長成分のうち光分波器を介して光伝送路に送出す
る波長成分が一方の光送信器については中央部の
波長成分であり、かつもう一方の光送信器につい
ては中央部以外の波長成分である光多重伝送シス
テムが得られる。 According to the present invention, two optical transmitters using light sources having substantially the same emission wavelength range and two optical receivers are connected to both ends of a single optical transmission line via an optical demultiplexer. In an optical multiplex transmission system in which the two optical transmitters are optically connected and perform multiplex transmission using the single optical transmission line, the two optical transmitters select an optical demultiplexer among the emission wavelength components of their light sources. An optical multiplex transmission system can be obtained in which the wavelength components sent to the optical transmission line through the optical transmitter are the central wavelength components for one optical transmitter, and the wavelength components outside the central region for the other optical transmitter. .
この光多重伝送システムは同じ発光波長域の光
源を使用し光分波器を介してその互いに異なる一
部波長成分のみを光伝送路に送出することによつ
て実効的に波長分割による多重伝送を行なうこと
ができるが、本発明ではさらに光伝送路に送出さ
れる波長成分を一方の光送信器では中心部の波長
成分を、またもう一方の光送信器では中央部以外
の波長成分を送出するようにしたことによつて、
温度などによる光源の発光波長の変化に対しても
安定な光多重伝送システムを構成することができ
る。 This optical multiplex transmission system effectively performs multiplex transmission by wavelength division by using light sources with the same emission wavelength range and sending only some mutually different wavelength components to the optical transmission line via an optical demultiplexer. However, in the present invention, one optical transmitter transmits wavelength components at the center, and the other optical transmitter transmits wavelength components other than the central wavelength components. By doing so,
It is possible to construct an optical multiplex transmission system that is stable even when the emission wavelength of the light source changes due to temperature or the like.
次に図面を参照して本発明について詳細に説明
する。 Next, the present invention will be explained in detail with reference to the drawings.
第１図は本発明の第１の実施例の光多重伝送シ
ステムの構成を示すブロツク図である。 FIG. 1 is a block diagram showing the configuration of an optical multiplex transmission system according to a first embodiment of the present invention.
第１図において光送信器１１，１２は光源にほ
ぼ同じ発光波長域を有する発光ダイオードを使用
し、それぞれ送信信号１１１，１１２を光信号１
２１，１２２に変換して送出するものである。ま
た光分波器３１，３２は帯域通過フイルタを使用
したもので、このフイルタは前記光源の発光波長
域のうちほぼ中心部の波長成分のみを透過しそれ
以外の波長成分を反射するものである。光送信器
１１からの出力光信号１２１のうち光分波器３１
を経て光伝送路１に送出されるのは、そのフイル
タを透過できる中心部の波長成分のみである。こ
の光信号１３１は、光伝送路１を伝搬したのち光
分波器３２に入射するが、その光信号１３１は中
心部の波長成分が主であるのでほとんど損失なく
光分波器３２を透過して光受信器２２に入力され
る。また光伝送路１の途中などでの後方散乱光お
よび端面などで生じた反射光は自局の光分波器３
１に帰つて来るが、中心部の波長成分がほとんど
であるので大部分は光分波器３１を透過しごく一
部が反射されて光受信器２１に廻り込むだけであ
る。 In FIG. 1, optical transmitters 11 and 12 use light-emitting diodes having almost the same emission wavelength range as light sources, and transmit transmission signals 111 and 112 respectively into optical signals 1 and 12.
21, 122 and sends it out. The optical demultiplexers 31 and 32 use band-pass filters, and these filters transmit only wavelength components approximately in the center of the emission wavelength range of the light source and reflect other wavelength components. . Of the output optical signal 121 from the optical transmitter 11, the optical demultiplexer 31
Only the central wavelength component that can pass through the filter is sent to the optical transmission line 1 through the filter. This optical signal 131 propagates through the optical transmission line 1 and then enters the optical demultiplexer 32, but since the optical signal 131 mainly consists of wavelength components at the center, it passes through the optical demultiplexer 32 with almost no loss. and is input to the optical receiver 22. In addition, the backscattered light in the middle of the optical transmission line 1 and the reflected light generated at the end face are collected by the optical demultiplexer 3 of the own station.
1, most of the wavelength components are in the center, so most of it passes through the optical demultiplexer 31 and only a small part is reflected and goes around to the optical receiver 21.
一方光送信器１２から送出された光信号１２２
の場合には、光分波器３２を経て中心部以外の波
長成分が光伝送路１に送出され、前述と同様に光
受信器２１に伝送される。同様に光伝送路１の途
中で生じた反射光はごく一部が光受信器２２に廻
り込むだけである。 On the other hand, the optical signal 122 sent out from the optical transmitter 12
In this case, wavelength components other than the central portion are sent out to the optical transmission line 1 via the optical demultiplexer 32, and transmitted to the optical receiver 21 in the same manner as described above. Similarly, only a small portion of the reflected light generated in the middle of the optical transmission line 1 goes around to the optical receiver 22.
従つて光分波器３１，３２の代わりに単に光方
向性結合器を使用した方式に比べて光送信信号が
自局の光受信器に廻り込む割合を大幅に少なくで
き、その分だけ光伝送路の許容損失が大きくでき
るので比較的長距離の双方向多重伝送ができる。 Therefore, compared to a system that simply uses an optical directional coupler instead of the optical demultiplexers 31 and 32, the rate at which the optical transmission signal goes around to the optical receiver of the own station can be significantly reduced, and the optical transmission is reduced by that amount. Since the allowable loss of the path can be increased, relatively long-distance bidirectional multiplex transmission is possible.
第２図は第１の実施例において温度変化などに
より発光ダイオードの発光波長が変化した場合の
様子を示した図である。第２図でイは発光ダイオ
ードの出力光の分光強度を、またロは光分波器を
構成するフイルタからの反射光の分光強度を示
す。さらにイおよびロにおいて実線は発光ダイオ
ードの波長ずれがない場合を示し、破線は一例と
して発光波長が長波長側にずれた場合を示す。第
２図ロに示されるように発光波長が変化した場合
でもこの実施例の構成によれば長波長側成分の増
減と短波長側成分の増減とがほぼ打消し合う関係
にあるので反射損失の変化はほとんど生じない。
また同様に透過損失についてもほとんど変化が生
じないので発光波長の変化に対しても安定な光多
重伝送システムを構成することができる。 FIG. 2 is a diagram showing a situation where the emission wavelength of the light emitting diode changes due to temperature change or the like in the first embodiment. In FIG. 2, A indicates the spectral intensity of the light output from the light emitting diode, and B indicates the spectral intensity of the reflected light from the filter constituting the optical demultiplexer. Furthermore, in A and B, the solid line shows the case where there is no wavelength shift of the light emitting diode, and the broken line shows, as an example, the case where the emission wavelength shifts to the longer wavelength side. Even if the emission wavelength changes as shown in FIG. Almost no changes occur.
Similarly, since there is almost no change in transmission loss, it is possible to construct an optical multiplex transmission system that is stable even when the emission wavelength changes.
第３図は本発明の第２の実施例の光多重伝送シ
ステムの構成を示すブロツク図で単一の光伝送路
１に２つの光信号を多重して一方向に多重伝送す
るものである。この実施例においても第１の実施
例と同様に光送信器１１，１２からはほぼ同じ波
長成分を有する光信号１２１，１２２が出力され
るが、第１の実施例と同様な光分波器３１を使用
して光送信器１１についてはその出力光信号１２
１のうち光分波器３１を透過する中心部の波長成
分のみが光伝送路１に送出され、一方光送信器１
２についてはその出力光信号１２２のうち光分波
器３１で反射する中心部以外の波長成分が光伝送
路１に送出される。この２種類の光信号は光伝送
路１を伝送されたのち光分波器３２に入射し、こ
こで中心部の波長成分を主とする光送信器１１か
らの光信号は光分波器３２を透過して光受信器２
１に入力され、一方中心部以外の波長成分を主と
する光送信器１２からの光信号は光分波器３２で
反射された光受信器２２に入力され、それぞれ電
気信号に変換されたのち元の信号が再生される。
なお若干の光信号電力が反対の光受信器に廻り込
むが、その強度は受信すべき光信号に比べてかな
り低いのでそれによる劣化はほとんどない。従つ
て同じ発光波長域の光源を使用して一方向の多重
伝送を行なうことができ、かつ発光波長の変化に
対しても安定なものを得ることができる。 FIG. 3 is a block diagram showing the configuration of an optical multiplex transmission system according to a second embodiment of the present invention, in which two optical signals are multiplexed on a single optical transmission line 1 and multiplexed transmitted in one direction. In this embodiment as well, the optical transmitters 11 and 12 output optical signals 121 and 122 having almost the same wavelength components as in the first embodiment, but an optical demultiplexer similar to the first embodiment For the optical transmitter 11 using 31, its output optical signal 12
1, only the central wavelength component that passes through the optical demultiplexer 31 is sent to the optical transmission line 1, while the optical transmitter 1
2, the wavelength components of the output optical signal 122 other than the central portion reflected by the optical demultiplexer 31 are sent to the optical transmission line 1. These two types of optical signals are transmitted through the optical transmission line 1 and then enter the optical demultiplexer 32, where the optical signal from the optical transmitter 11 containing mainly the central wavelength component is sent to the optical demultiplexer 32. through the optical receiver 2
1, while the optical signal from the optical transmitter 12 containing mainly wavelength components other than the central part is reflected by the optical demultiplexer 32 and input to the optical receiver 22, where each is converted into an electrical signal. The original signal is regenerated.
Although some optical signal power goes around to the opposite optical receiver, its intensity is considerably lower than that of the optical signal to be received, so there is almost no deterioration due to this. Therefore, it is possible to perform unidirectional multiplex transmission using light sources in the same emission wavelength range, and it is also possible to obtain something that is stable against changes in the emission wavelength.
上上記の各実施例で光分波器３１，３２には帯
域透過フイルタを使用しているが、帯域阻止フイ
ルタを使用しても同様な性能を得ることができ
る。なおそのようなフイルタとしては誘電体多層
膜を用いた干渉フイルタが使用できるが、その他
透過域以外の光が反射されるタイプのフイルタで
あれば使用できる。 Although band transmission filters are used in the optical demultiplexers 31 and 32 in each of the above embodiments, similar performance can be obtained by using band rejection filters. Note that an interference filter using a dielectric multilayer film can be used as such a filter, but any other type of filter that reflects light outside the transmission range can also be used.
なお光分波器の中心波長はおおむね光源の発光
中心波長に合つていればよく、また２個の光源の
発光波長域も概略一致していればよい。 It is sufficient that the center wavelength of the optical demultiplexer roughly matches the emission center wavelength of the light source, and the emission wavelength ranges of the two light sources also need to roughly match.
以上詳述したように本発明によれば実質的に同
じ発光波長域を有する光源を使用した場合でも比
較的長距離の多重伝送が可能でかつ温度などによ
る発光波長域の変化に対しても安定な光多重伝送
システムを得ることができる。 As detailed above, according to the present invention, even when using light sources having substantially the same emission wavelength range, multiplex transmission over a relatively long distance is possible, and it is stable even when the emission wavelength range changes due to temperature etc. An optical multiplex transmission system can be obtained.
第１図と第３図はそれぞれ本発明の第１と第２
の実施例の構成を示すブロツク図で、また第２図
は光信号の分光強度を示した図である。
１……光伝送路、１１，１２……光送信器、２
１，２２……光受信器、３１，３２……光分波
器。
1 and 3 are the first and second embodiments of the present invention, respectively.
FIG. 2 is a block diagram showing the configuration of an embodiment of the present invention, and FIG. 2 is a diagram showing the spectral intensity of an optical signal. 1... Optical transmission line, 11, 12... Optical transmitter, 2
1, 22... optical receiver, 31, 32... optical demultiplexer.
Claims (1)
た２台の光送信器と、２台の光受信器とが光分波
器を介して単一の光伝送路の両端に光学的に接続
されており、前記単一の光伝送路を使用して多重
伝送を行なう光多重伝送システムにおいて、前記
２台の光送信器がその光源の発光波長域のうち光
分波器を介して光伝送路に送出する波長成分が一
方の光送信器については中央部の波長成分であ
り、かつもう一方の光送信器については中央部以
外の波長成分であることを特徴とする光多重伝送
システム。1 Two optical transmitters using light sources with substantially the same emission wavelength range and two optical receivers are optically connected to both ends of a single optical transmission line via an optical demultiplexer. In the optical multiplexing transmission system that performs multiplex transmission using the single optical transmission line, the two optical transmitters transmit optical signals within the emission wavelength range of their light sources via an optical demultiplexer. 1. An optical multiplex transmission system characterized in that the wavelength components transmitted to the optical path are wavelength components in a central region for one optical transmitter, and wavelength components in a region other than the central region for the other optical transmitter.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP7447280A JPS56169948A (en) | 1980-06-03 | 1980-06-03 | Optical multiplex transmission system |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP7447280A JPS56169948A (en) | 1980-06-03 | 1980-06-03 | Optical multiplex transmission system |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JPS56169948A JPS56169948A (en) | 1981-12-26 |
| JPS6318901B2 true JPS6318901B2 (en) | 1988-04-20 |
Family
ID=13548223
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP7447280A Granted JPS56169948A (en) | 1980-06-03 | 1980-06-03 | Optical multiplex transmission system |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JPS56169948A (en) |
Cited By (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS63103802U (en) * | 1986-12-26 | 1988-07-06 | ||
| JPS6414301U (en) * | 1987-04-03 | 1989-01-25 | ||
| JPS6480306A (en) * | 1987-09-21 | 1989-03-27 | Tsuneo Yoshimura | Method of activating solution for permanent waving |
| JPH01300904A (en) * | 1988-05-24 | 1989-12-05 | Seikichi Boku | Cold wave method of permanent wave |
| JPH0399501U (en) * | 1990-02-01 | 1991-10-17 |
Families Citing this family (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| FR2537364A1 (en) * | 1982-12-01 | 1984-06-08 | Instruments Sa | Method of transmitting information by optical fibre and device for implementing the method. |
-
1980
- 1980-06-03 JP JP7447280A patent/JPS56169948A/en active Granted
Cited By (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS63103802U (en) * | 1986-12-26 | 1988-07-06 | ||
| JPS6414301U (en) * | 1987-04-03 | 1989-01-25 | ||
| JPS6480306A (en) * | 1987-09-21 | 1989-03-27 | Tsuneo Yoshimura | Method of activating solution for permanent waving |
| JPH01300904A (en) * | 1988-05-24 | 1989-12-05 | Seikichi Boku | Cold wave method of permanent wave |
| JPH0399501U (en) * | 1990-02-01 | 1991-10-17 |
Also Published As
| Publication number | Publication date |
|---|---|
| JPS56169948A (en) | 1981-12-26 |
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