JPS583431A - Optical transmitter and receiver - Google Patents
Optical transmitter and receiverInfo
- Publication number
- JPS583431A JPS583431A JP56100597A JP10059781A JPS583431A JP S583431 A JPS583431 A JP S583431A JP 56100597 A JP56100597 A JP 56100597A JP 10059781 A JP10059781 A JP 10059781A JP S583431 A JPS583431 A JP S583431A
- Authority
- JP
- Japan
- Prior art keywords
- signal
- optical
- analog signal
- electric signal
- high frequency
- 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.)
- Granted
Links
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
- H04B10/50—Transmitters
Landscapes
- Physics & Mathematics (AREA)
- Electromagnetism (AREA)
- Engineering & Computer Science (AREA)
- Computer Networks & Wireless Communication (AREA)
- Signal Processing (AREA)
- Optical Communication System (AREA)
Abstract
Description
【発明の詳細な説明】
本発明はビデオ信号のようなアナログ信号をレーザダイ
オードを用いて光ファイバを伝送する光送受信装置に関
するものである。DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an optical transmitter/receiver that transmits an analog signal such as a video signal through an optical fiber using a laser diode.
従来のこの種の光送受信装置は、あとに図面を用いて説
明するが、入力したアナログ信号を増幅し、増幅した信
号を変調信号としてし゛−ザダイオードを駆動して光信
号を出射する送信部と、出射した光信号を光ファイバで
伝送する光線路部と、光フアイバ出射光゛を光電素子で
電気信号に変換し、この電気信号を増幅してアナログ信
号を再生して出力する光受信部とから成っていた。This type of conventional optical transmitter/receiver, which will be explained later using drawings, has a transmitter that amplifies an input analog signal, uses the amplified signal as a modulation signal, drives a diode, and outputs an optical signal. , an optical line section that transmits the emitted optical signal through an optical fiber, and an optical receiver section that converts the emitted light from the optical fiber into an electrical signal using a photoelectric element, amplifies this electrical signal, regenerates an analog signal, and outputs it. It consisted of.
しかし乍ら上記のような装置においては、これ又あとに
詳しく説明するが、レーザダイオードの電流−光出力特
性（Ｉ−Ｌ特性）で示されるキンク或いは曲シなどの非
直線性によりアナログ信号に波形歪が生じるという欠点
があった。又、レーザダイオードのコヒーレント々出力
光は光フアイバ伝播中に各モード間での伝播時間差がレ
ーデダイオードのコヒーレント長よりも短い場合にモー
ド間干渉が起き÷啼このモード間干渉に起因して光器で
その１ま光検波される。従って、再生されたアナログ信
号は非直線性歪が劣化し１例えばビデオ信号のＤＧ −
ＤＰ特性に劣化が生じるという欠点があった。However, in the above-mentioned device, as will be explained in detail later, non-linearities such as kinks or curvatures shown in the current-light output characteristics (IL characteristics) of the laser diode cause the analog signal to be distorted. There was a drawback that waveform distortion occurred. In addition, when the coherent output light of a laser diode is propagated through an optical fiber, if the propagation time difference between each mode is shorter than the coherent length of the laser diode, inter-mode interference occurs. The first one is optically detected by the detector. Therefore, the reproduced analog signal has degraded non-linear distortion.For example, DG - of a video signal.
There was a drawback that the DP characteristics deteriorated.
上記の従来装置の欠点の説明において、前者の波形歪み
は広く知られていることであり、これに対しレーザダイ
オードの改良がなされているが。In explaining the drawbacks of the conventional devices above, the former waveform distortion is widely known, and improvements have been made to laser diodes to address this problem.
壕だ満足すべきものは得られて−いない。１だ後者の波
形歪みはＲ，Ｅ、 Ｅｐｗｏｒｔｈが１９７８年９月の
Ｐｒｏｅ、 ４ ｔｈＥｕｒｏｐｅａｎ Ｃｏｎｆｅｒ
ｅｎｃｅ ｏｎ ０ｐｔｉｃａｌＦｉｂｅｒ Ｃｏｍｍ
ｕｎｉｃａｔｉｏｎにおいて６アナログ・ディジタル光
フアイバシステムにおけるモード雑音現象”と題する論
文において指摘したも゛ので、併せてその対策について
も説明を行っているが、実際の装装置においてモード雑
音を無視できるところまで小さくすることは容易ではな
いように思われる。Unfortunately, I haven't gotten anything satisfying. 1. The latter waveform distortion is R, E, Epworth is Proe of September 1978, 4th European Conference
ence on OpticalFiber Comm
This was pointed out in a paper entitled ``Modal Noise Phenomenon in Analog/Digital Optical Fiber Systems'' in the 6th International Conference on Analog/Digital Optical Fiber Systems, and we also explain countermeasures for this problem. It seems that it is not easy to do.
従って本発明の目的は、前述のようなアナログ信号を光
フアイバ信号を光フアイバ伝送する光送受信装置におい
て、し〜ザダイオードおよび光フアイバ伝送路自身の特
性の改良とは別の形でレーザダイオードのＩ−Ｌ特性の
非直線性および光フアイバ伝送の非直性の影響を緩和さ
せて、非直線性による波形の劣化を軽減させた光送受信
装置を提供しようとするものである。Therefore, an object of the present invention is to improve the characteristics of the laser diode and the optical fiber transmission line in addition to improving the characteristics of the diode and the optical fiber transmission line itself in an optical transmitting/receiving apparatus that transmits an analog signal through an optical fiber as described above. It is an object of the present invention to provide an optical transmitting/receiving device in which the effects of nonlinearity of IL characteristics and nonlinearity of optical fiber transmission are alleviated, and deterioration of waveforms due to nonlinearity is reduced.
本発明は上記の目的を達成するために、アナログ信号に
高周波信号を混合して波高値を平均化することにより波
形歪を除去するようにしたものである。In order to achieve the above object, the present invention removes waveform distortion by mixing a high frequency signal with an analog signal and averaging the peak values.
すなわち本発明によれば、入力アナログ信号に基づく変
調信号にょシレーデダイオードを駆動して光信号を出射
する光送信部と、前記出射された光信号を伝送する光線
路部と、この光線路部からの光信号を光電素子にょ）電
気信号に変換しこの電気信号から前記入力アナログ信号
に対応する出力アナログ信号を発生する光受信部とから
成る光送受信装置において、前記光送信部に、前記入力
アナログ信号の有する周波数成分より高い周波数領域に
スペクトラムを持つ高周波電気信号を発生する高周波発
生回路と、前記高周波電気信号および８’＋」記入力ア
ナログ信号を合成し１合成した信号から前記入力アナロ
グ信号に基づく変調信号が得られるように配置された合
成回路と“を設け、前記光受信部の信号線路に、前記高
周波電気信号の周波数成分を阻正する沖波器を設けて成
ることを特徴とする光送受信装置が得られる。 ・
次に図面を参照して詳細に説明する。That is, according to the present invention, an optical transmission section that outputs an optical signal by driving a modulated signal based on an input analog signal to output an optical signal, an optical line section that transmits the emitted optical signal, and this optical line section and an optical receiver that converts an optical signal from a photoelectric element into an electrical signal and generates an output analog signal corresponding to the input analog signal from the electrical signal, wherein the optical transmitter A high frequency generation circuit that generates a high frequency electric signal having a spectrum in a frequency region higher than the frequency components of the analog signal, and the high frequency electric signal and the 8'+'' input analog signal are synthesized, and the input analog signal is obtained from the combined signal. and a combining circuit arranged so as to obtain a modulated signal based on the optical receiver, and an Oki transducer for blocking frequency components of the high-frequency electrical signal is provided on the signal line of the optical receiver. An optical transceiver device is obtained.・
Next, a detailed description will be given with reference to the drawings.
第１図は従来のこの種の光送受信装置における光痛信系
の構成例を示した図である。第１図の左側の送信部（Ｉ
）において、入力端１に加えられるアナログ信号は、光
送信回路２を経てＶ−ザダイオード３を駆動し、光強度
変調された光信号に変換する。このＶ−ザダ１オード３
の光信号は光ファイバ４により図の右側の受信部（ｎ）
に光伝送される０この光フアイバ出射光は受光素子５に
より光検波されて電気信号に変換され、変換された電気
信号は光受信回路６で増幅され、出力端７にアナログ信
号が再生される。FIG. 1 is a diagram showing an example of the configuration of an optical communication system in a conventional optical transmitter/receiver of this type. The transmitter on the left side of Figure 1 (I
), an analog signal applied to an input terminal 1 passes through an optical transmission circuit 2, drives a V-the diode 3, and is converted into an optical signal modulated in optical intensity. This V-Zada 1 Ord 3
The optical signal is transmitted via optical fiber 4 to the receiving section (n) on the right side of the figure.
This optical fiber emitted light is optically transmitted to the optical fiber and is optically detected by the light receiving element 5 and converted into an electrical signal.The converted electrical signal is amplified by the optical receiving circuit 6 and an analog signal is reproduced at the output end 7. .
第２図面の簡単な説明したＶ−ザダイオードの駆動電流
Ｉと出力光りの関係の一例を示した図で、キンク或いは
曲シなどの非直線が明確にあ゛られれでおシ、アナログ
信号をこの特性のまま光強度変調すれば波形歪を生じる
ことを示している。This is a diagram showing an example of the relationship between the drive current I of the V-the diode and the output light, which was briefly explained in the second drawing. This shows that if the light intensity is modulated with this characteristic, waveform distortion will occur.
なおこの特性は最近のＶ−ザダイオードでは相当改善さ
れているが、まだそのままで使用した場合好ましくない
波形歪が残っている。また実際にＶ−ザタイドに印加す
る電流には、この波形の直線に近い部分の中央に近いＩ
６に相当するバイアス電流を附加している。Although this characteristic has been considerably improved in recent V-the diodes, undesirable waveform distortion still remains when used as is. In addition, the current actually applied to V-the tide includes I
A bias current equivalent to 6 is added.
第３図は本発明によるアナログ信号の光通信システム構
成の一実施例を示した図である。第３図においては前記
第１図を参照して説明した構成要素に共通した部分があ
るので、第３図中第１図と同一部分の構成要素について
は同一符号を付して説明を省略し、以下異なる部分につ
いて説明する。FIG. 3 is a diagram showing an embodiment of the configuration of an analog signal optical communication system according to the present invention. In Fig. 3, there are parts common to the constituent elements explained with reference to Fig. 1 above, so the constituent elements in Fig. 3 that are the same as those in Fig. 1 are given the same reference numerals and explanations are omitted. , the different parts will be explained below.
１１は高周波雑音発生回路であり、アナログ信号の有す
る周波数成分よりも高い周波数領域にスペクトラムをも
つ雑音状電気信号Ｂを発生する。Reference numeral 11 denotes a high frequency noise generation circuit, which generates a noise-like electrical signal B having a spectrum in a frequency region higher than the frequency components of the analog signal.
１２は混合器であシ、アナログ信号Ａと高周波雑音発生
回路１１の雑音状電気信号Ｂとを合成し。12 is a mixer which combines the analog signal A and the noise-like electric signal B from the high frequency noise generating circuit 11.
合成した電気信号Ｃを発する。１３は低域ｐ波器であり
、光受信回路６の出力電気信号Ｆに含まれる雑石状電気
信号を分離し、アナログ信号Ｇのみを取り出すものであ
る。A synthesized electrical signal C is emitted. Reference numeral 13 denotes a low-frequency p-wave device, which separates the gravel-like electrical signal contained in the output electrical signal F of the optical receiver circuit 6 and extracts only the analog signal G.
第４図および第５図にぼ第３図の各部に対応する信号波
形の交流成分およびスペクトラムをそれぞれ示す図であ
る。以下第３図〜第５図を併用して説明すると、入力端
１に加えられるアナログ信号Ａと高周波雑音発生回路１
１からの雑音状電気４５号Ｂとを混合器１２で合成し、
この合成した電気信号Ｃで光送信回路２によりバイアス
されたレーザダイオード３を光強度変調するＯＶ−ザダ
イオード３の出力光りは光ラアイバ４により光伝送され
る。この光ファイバ４の出射光Ｅは受光素子５によシ光
検波されて電気信号に変換される。この電気信号は光受
信回路６で増幅され、増幅された電気信号Ｆは低域沖波
器１３によシ雑音状電気信号成分を分離して、アナログ
信号Ｇが出力端７也
に可成される。FIG. 4 and FIG. 5 are diagrams showing AC components and spectra of signal waveforms corresponding to each part of FIG. 3, respectively. To explain the following using FIGS. 3 to 5, the analog signal A applied to the input terminal 1 and the high frequency noise generation circuit 1
Noise-like electricity No. 45 B from 1 is synthesized in a mixer 12,
The output light of the OV-the diode 3, which modulates the optical intensity of the laser diode 3 biased by the optical transmission circuit 2 with this combined electrical signal C, is optically transmitted by the optical driver 4. The emitted light E from the optical fiber 4 is optically detected by the light receiving element 5 and converted into an electrical signal. This electrical signal is amplified by the optical receiving circuit 6, and the amplified electrical signal F is separated from the noise-like electrical signal component by the low-frequency wave transducer 13, and an analog signal G is generated at the output terminal 7. .
従って、伝送するアナログ信号をそのまｉｖ−ザダイオ
ードで光強度変調して光伝送中にアナログ信号が直接に
波形歪の影響を受ける第１図の従来の光送受信装置とは
異なり１本発明では伝送するアナログ信号よりももつと
周期の速い雑音状電気信号で変調した電気信号をレーザ
ダイオードで光強度変調することにより、レーザダイオ
ードのＩ−Ｌ特性の非直線性および光ファイ・々伝送の
非直線性による波形歪が平均化される。この平均化され
た光波形を受光器で電気信号に変換して低域ろ波器で炉
液されて取シ出されたアナログ信号の波形は、歪が平均
化されているので波形歪の劣化を軽減することができる
０
以上述べたように、Ｖ−ザダイオードを用いたアナログ
信号の光送受信装置による光通信システムにおいて、Ｖ
−ザダイオード及び光ファイ／々の非直線性による波形
歪劣化を軽減でき９例えばビデオ信号のｌ）Ｇ・ＤＰ特
性における改善がなされ・高品質のアナログ信号伝送を
実現することができる。Therefore, unlike the conventional optical transmitter/receiver shown in FIG. 1, in which the analog signal to be transmitted is directly modulated in optical intensity by the iv-the diode, and the analog signal is directly affected by waveform distortion during optical transmission, the present invention By using a laser diode to modulate the optical intensity of an electrical signal modulated with a noise-like electrical signal whose period is faster than that of the analog signal to be transmitted, the nonlinearity of the I-L characteristic of the laser diode and the nonlinearity of optical fiber-to-optical transmission can be reduced. Waveform distortion due to linearity is averaged out. This averaged optical waveform is converted into an electrical signal by a photoreceiver, and the waveform of the analog signal is filtered out by a low-pass filter and taken out.Since the distortion has been averaged, the waveform distortion deteriorates. 0 As mentioned above, in an optical communication system using an analog signal optical transmitter/receiver using a V-the diode, V
- Waveform distortion deterioration due to non-linearity of the diode and optical fiber can be reduced; for example, l) G/DP characteristics of video signals can be improved; and high-quality analog signal transmission can be realized.
なお、上記例においてはアナログ信号をこれより速い周
期の雑音状電気信号で変調した電気信号でＶ−ザダイオ
ードを光強度変調したが、アナログ１１号をこれより周
期の速いノ４ルス信号で変調した電気信号でレーザダイ
オードを光強度変調して。In the above example, the optical intensity of the V-the diode was modulated with an electrical signal obtained by modulating the analog signal with a noise-like electrical signal with a faster period, but analog No. 11 was modulated with a noise-like electrical signal with a faster period than this. The electrical signal is used to modulate the light intensity of a laser diode.
高品質のアナログ信号と本来歪劣化の影曽が比較的少な
いディジタル信号とを同時に伝送するノ・イｙＺＩＪノ
ド光伝送を太細することも可能である。なお、この場合
はアナログ信号のみ波形歪劣化の改善がなされる。また
受信部（１）において、混合器１２を光送信回路２の増
幅回路の途中に配置してもよく、同様な意味で受信部（
Ｉｔ）において低域Ｆ波器１３を光受信回路６の増幅器
の中段に配置してもよい。It is also possible to widen and narrow the ZIJ-node optical transmission, which simultaneously transmits a high-quality analog signal and a digital signal that is inherently relatively free from distortion degradation. Note that in this case, only the analog signal is improved in waveform distortion deterioration. Further, in the receiving section (1), the mixer 12 may be placed in the middle of the amplifier circuit of the optical transmitting circuit 2, and in the same sense, the receiving section (
In It), the low-frequency F wave amplifier 13 may be placed in the middle stage of the amplifier of the optical receiving circuit 6.
第１図は従来のアナログ価号光送受信装置を用いた光通
信システムの構成図、第２図はＶ−ザダイオードの非直
線性を示すＩ−Ｌ特性図、第３図は本発明を用いた光通
信システムの構成図、第４図は本発明各部を説明するだ
めの信号波形図、第５図は第４図の信号波形に対応する
スペクトラム図である。
記号の説明：２は光送信回路、３はレーザダイオード、
４は光ファイ・々、５は受光素子、６は光受信回路、１
１は高周波雑音発生回路、１２は混合器、１３は低域ろ
波器をそれぞれあられしている０
第１図
ＣＩ） （Ｉｔ）第２図
第３図
Δ
Ｉ
第４図
Ａ ８．ＣＤ Ｅ Ｆ Ｇ弗
５図Fig. 1 is a configuration diagram of an optical communication system using a conventional analog signal optical transmitter/receiver, Fig. 2 is an I-L characteristic diagram showing the nonlinearity of the V-the diode, and Fig. 3 is an optical communication system using the present invention. FIG. 4 is a signal waveform diagram for explaining each part of the present invention, and FIG. 5 is a spectrum diagram corresponding to the signal waveform in FIG. 4. Explanation of symbols: 2 is an optical transmitter circuit, 3 is a laser diode,
4 is an optical fiber, 5 is a light receiving element, 6 is an optical receiving circuit, 1
1 is a high frequency noise generation circuit, 12 is a mixer, and 13 is a low-pass filter. 0 Fig. 1 CI) (It) Fig. 2 Fig. 3 Δ I Fig. 4 A 8. CD E F G 弗5
Claims (1)
ダイオードを駆動して光信号を出射する光送信部と、前
記出射された光信号を伝送する光線路部と、この光線路
部からの光信号を光電素子により電気信号に変換しこの
電気信号から前記入力アナログ信号に対応する出力アナ
ログ信号を発生する光受信部とから成る光送受信装置に
おいて。 前記光送信部に、前記入力アナログ信号の有する周波数
成分より高い周波数領域にスペクトラムを持つ高周波電
気信号を発生する高周波発生回路と。 前記高周波電気信号および前記入力アナログ信号を合成
し９合成した信号から前記入力アナログ信号に基づく変
調信号が得られるように配置された合成回路とを設け、
前記光受信部の信号線路に。 前記高周波電気信号の周波数成分を阻止するＦ波器を設
けて成ることを特徴とする光送受信装置。[Claims] 1. An optical transmission section that drives a laser diode with a modulation signal based on an input analog signal to output an optical signal, an optical line section that transmits the output optical signal, and this optical beam. An optical transmitting/receiving device comprising: an optical receiving section that converts an optical signal from a path section into an electrical signal using a photoelectric element, and generates an output analog signal corresponding to the input analog signal from the electrical signal. A high frequency generation circuit that generates a high frequency electric signal having a spectrum in a frequency region higher than the frequency components of the input analog signal in the optical transmitter. a synthesis circuit arranged to synthesize the high frequency electric signal and the input analog signal and obtain a modulation signal based on the input analog signal from the synthesized signal;
to the signal line of the optical receiver. An optical transmitting/receiving device comprising an F-wave device that blocks frequency components of the high-frequency electrical signal.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP56100597A JPS583431A (en) | 1981-06-30 | 1981-06-30 | Optical transmitter and receiver |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP56100597A JPS583431A (en) | 1981-06-30 | 1981-06-30 | Optical transmitter and receiver |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JPS583431A true JPS583431A (en) | 1983-01-10 |
| JPS624899B2 JPS624899B2 (en) | 1987-02-02 |
Family
ID=14278271
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP56100597A Granted JPS583431A (en) | 1981-06-30 | 1981-06-30 | Optical transmitter and receiver |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JPS583431A (en) |
Cited By (8)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS6273675U (en) * | 1985-10-28 | 1987-05-12 | ||
| JPS6432768A (en) * | 1987-07-29 | 1989-02-02 | Nippon Chemicon | Fly-back line erasing circuit for cathode ray tube |
| JPH039627A (en) * | 1989-06-06 | 1991-01-17 | Nec Corp | Optical transmission equipment |
| FR2683401A1 (en) * | 1991-10-31 | 1993-05-07 | Alcatel Nv | OPTICAL GENERATOR, IN PARTICULAR FOR THE TRANSPORT OF A HYPERFREQUENCY SIGNAL. |
| EP0613262A1 (en) * | 1993-02-24 | 1994-08-31 | Koninklijke KPN N.V. | Optical noise source |
| US5550667A (en) * | 1992-08-22 | 1996-08-27 | Alcatel N.V. | Optical transmitter |
| US5598288A (en) * | 1995-07-31 | 1997-01-28 | Northrop Grumman Corporation | RF fiber optic transmission utilizing dither |
| GB2426398A (en) * | 2005-05-17 | 2006-11-22 | Toshiba Kk | Optical communication system which reduces stimulated Brillouin scattering by electrically multiplexing noise with the data signal to be transmitted |
Families Citing this family (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPH01107648A (en) * | 1987-07-24 | 1989-04-25 | Nippon Denso Co Ltd | Three position rotation actuator |
| JPH04133653A (en) * | 1990-09-25 | 1992-05-07 | Nippondenso Co Ltd | Actuator for multistage position control |
Citations (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS57135535A (en) * | 1981-02-13 | 1982-08-21 | Mitsubishi Electric Corp | Analog modulation system of semiconductor laser |
-
1981
- 1981-06-30 JP JP56100597A patent/JPS583431A/en active Granted
Patent Citations (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS57135535A (en) * | 1981-02-13 | 1982-08-21 | Mitsubishi Electric Corp | Analog modulation system of semiconductor laser |
Cited By (14)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS6273675U (en) * | 1985-10-28 | 1987-05-12 | ||
| JPH054369Y2 (en) * | 1985-10-28 | 1993-02-03 | ||
| JPS6432768A (en) * | 1987-07-29 | 1989-02-02 | Nippon Chemicon | Fly-back line erasing circuit for cathode ray tube |
| JPH0436629B2 (en) * | 1987-07-29 | 1992-06-16 | Nippon Chemicon | |
| JPH039627A (en) * | 1989-06-06 | 1991-01-17 | Nec Corp | Optical transmission equipment |
| US5311531A (en) * | 1991-10-31 | 1994-05-10 | Alcatel N.V. | Light generator, in particular for conveying a microwave signal |
| FR2683401A1 (en) * | 1991-10-31 | 1993-05-07 | Alcatel Nv | OPTICAL GENERATOR, IN PARTICULAR FOR THE TRANSPORT OF A HYPERFREQUENCY SIGNAL. |
| US5550667A (en) * | 1992-08-22 | 1996-08-27 | Alcatel N.V. | Optical transmitter |
| EP0613262A1 (en) * | 1993-02-24 | 1994-08-31 | Koninklijke KPN N.V. | Optical noise source |
| US5401955A (en) * | 1993-02-24 | 1995-03-28 | Koninklijke Ptt Nederland N.V. | Optical noise source having three input signals |
| US5598288A (en) * | 1995-07-31 | 1997-01-28 | Northrop Grumman Corporation | RF fiber optic transmission utilizing dither |
| GB2426398A (en) * | 2005-05-17 | 2006-11-22 | Toshiba Kk | Optical communication system which reduces stimulated Brillouin scattering by electrically multiplexing noise with the data signal to be transmitted |
| GB2426398B (en) * | 2005-05-17 | 2008-05-07 | Toshiba Kk | Optical communication system and optical transmitting apparatus for the same |
| US7634199B2 (en) | 2005-05-17 | 2009-12-15 | Kabushiki Kaisha Toshiba | Optical communication system and optical transmitting apparatus for the same |
Also Published As
| Publication number | Publication date |
|---|---|
| JPS624899B2 (en) | 1987-02-02 |
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