JPS6364418A - Light transmission system - Google Patents
Light transmission systemInfo
- Publication number
- JPS6364418A JPS6364418A JP61207710A JP20771086A JPS6364418A JP S6364418 A JPS6364418 A JP S6364418A JP 61207710 A JP61207710 A JP 61207710A JP 20771086 A JP20771086 A JP 20771086A JP S6364418 A JPS6364418 A JP S6364418A
- Authority
- JP
- Japan
- Prior art keywords
- frequency
- modulator
- phase
- code
- amplitude
- 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
- 230000005540 biological transmission Effects 0.000 title claims abstract description 51
- 230000010287 polarization Effects 0.000 claims abstract description 34
- 230000004907 flux Effects 0.000 claims abstract description 10
- 230000003287 optical effect Effects 0.000 claims description 14
- 230000002452 interceptive effect Effects 0.000 abstract description 3
- 238000001514 detection method Methods 0.000 abstract description 2
- 238000010586 diagram Methods 0.000 description 8
- 238000000034 method Methods 0.000 description 8
- 230000000694 effects Effects 0.000 description 4
- 230000001427 coherent effect Effects 0.000 description 3
- 239000000835 fiber Substances 0.000 description 2
- 239000013307 optical fiber Substances 0.000 description 2
- 230000000644 propagated effect Effects 0.000 description 1
- 230000001172 regenerating effect Effects 0.000 description 1
- 239000004065 semiconductor 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、情報を光信号として光ファイバを伝送させる
方式に関するものである。DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a system for transmitting information as an optical signal through an optical fiber.
光ファイバを用いた情報の伝送方式として、従来、光強
度を変調する強度変調方式と二光束の干渉を利用したコ
ヒーレント伝送方式とがあり、後者の方式には、光波の
振幅、周波数、位相を変調する方式があった。Conventional information transmission methods using optical fibers include an intensity modulation method that modulates the light intensity and a coherent transmission method that uses interference between two beams of light.The latter method involves modulating the amplitude, frequency, and phase of light waves. There was a method to modulate it.
しかし、このような従来の光伝送方式は、各々の変調方
式を単独で使用する方式であるため、たとえ、変調に用
いる強度、振幅、周波数、位相を多値化しても、各変調
方式を単独に用いる限りそれ以上には情報伝送速度を向
上し得ないという欠点があった。However, such conventional optical transmission systems use each modulation method independently, so even if the intensity, amplitude, frequency, and phase used for modulation are multivalued, each modulation method is used independently. The drawback is that the information transmission speed cannot be improved any further if used for this purpose.
本発明は、光束の性質である偏光状態、周波数、位相を
個別の情報として利用し、光束の干渉性を利用して、信
号対雑音比が高く大きな情報伝送速度を有する大容量の
光伝送方式を提供することを目的としている。The present invention utilizes the polarization state, frequency, and phase, which are the properties of a light flux, as individual information, and utilizes the coherence of the light flux to create a large-capacity optical transmission system that has a high signal-to-noise ratio and a high information transmission rate. is intended to provide.
本発明によれば、上述の目的は、前記特許請求の範囲に
記載したとおり、光束を振幅と周波数および位相が同一
で互いに直交する偏光波に変換する手段と、光束を振幅
と偏光状態および位相が同一で周波数が二種類あるいは
それ以上の異なる偏光波に変換する手段と、光束を振幅
と偏光状態および周波数が同一で二種類あるいはそれ以
上の異なる位相の偏光波に変換する手段と、光束を偏光
状態と周波数および位相が同一で二種類あるいはそれ以
上の異なる振幅の偏光波に変換する手段と、これらの偏
光波のうちの二種類あるいはそれ以上の偏光波を人為的
に形成した符号列に対応付ける手段と、これらの偏光波
の一つを選択し時系列的に並んだ偏光波の列として伝送
媒体に入射する手段と、該伝送媒体から出射した時系列
的に並んだ偏光波の列に局発光源から出射した光束を合
波して干渉波を形成する手段と、一つの偏光波を選択し
選択した偏光波を人為的に形成された情報として再現す
る手段とを具備する系によって、空間的に隔たった場所
に情報を伝送することを特徴とする光伝送方式により達
成される。According to the present invention, the above object is to provide means for converting a light beam into polarized waves having the same amplitude, frequency and phase and orthogonal to each other; a means for converting a light beam into two or more different polarized waves having the same frequency and two or more different frequencies; a means for converting a light beam into two or more different phases having the same amplitude, polarization state, and frequency; means for converting into two or more types of polarized waves with the same polarization state, frequency, and phase but different amplitudes, and a code string that artificially forms two or more types of polarized waves among these polarized waves. a means for associating one of the polarized waves, a means for selecting one of these polarized waves and inputting it into a transmission medium as a chronologically arranged sequence of polarized waves; By a system comprising means for combining light beams emitted from a local light source to form an interference wave, and means for selecting one polarized wave and reproducing the selected polarized wave as artificially formed information, This is achieved using an optical transmission system that is characterized by transmitting information to spatially separated locations.
本発明による光伝送方式は」二連の手段によって、光波
の偏光状態、周波数、位相を個々の符号状態として利用
し、その内の一つを選択して、伝送媒体を介して離れた
場所に符号列として伝送し、伝送した符号列ともう一つ
の光波を用いて干渉させて情報を再生さすることにより
、情報伝送速度と信号対雑音比を高めた大容量の光伝送
方式を得るものである。The optical transmission system according to the present invention utilizes the polarization state, frequency, and phase of a light wave as individual code states by two means, selects one of them, and transmits it to a remote location via a transmission medium. By transmitting the code as a code string and regenerating the information by interfering with the transmitted code string using another light wave, a large-capacity optical transmission system with high information transmission speed and signal-to-noise ratio can be obtained. be.
第１図は本発明の第一の実施例の光伝送シス°−３シ テムの構成を示すブロック図である。 FIG. 1 shows an optical transmission system °-3 system according to the first embodiment of the present invention. FIG. 2 is a block diagram showing the configuration of the system.
第１図において、光源１は可干渉性の光束を出力する。In FIG. 1, a light source 1 outputs a coherent light beam.
−例として半導体レーザがある。- An example is a semiconductor laser.
この光束は、例えば磁気光学効果を利用した７アラデイ
回転子等で構成された偏光状態変調器２により偏光状態
変調が施される。偏光状態変調が施された光束は、例え
ば電気光学効果を利用した周波数変調器３で周波数変調
を施される。This light flux is subjected to polarization state modulation by a polarization state modulator 2 composed of, for example, a 7 Alladay rotator utilizing the magneto-optic effect. The light flux subjected to polarization state modulation is subjected to frequency modulation by a frequency modulator 3 that utilizes, for example, an electro-optic effect.
周波数変調器３で周波数置ｍされた光束は、例えば電気
光学効果を利用した位相変調器４で位相変調される。位
相変調器４で位相変調された光束は例えば減實器等で構
成された振幅変調器５で振幅変調される。送信すべき情
報は符号発生器６により例えば振幅値で区別された多値
符号に変換される。信号制御器７は符号発生器６の多値
符号出力に応じて、偏光波を送出で島るように偏光状態
変調器２、周波数変調器３、位相変調器４、および振幅
変調器５を制御する。The light flux modulated by the frequency modulator 3 is phase-modulated by a phase modulator 4 that utilizes, for example, an electro-optic effect. The light beam phase-modulated by the phase modulator 4 is amplitude-modulated by an amplitude modulator 5, which includes, for example, an attenuator. The information to be transmitted is converted by the code generator 6 into a multilevel code differentiated by amplitude value, for example. The signal controller 7 controls the polarization state modulator 2 , the frequency modulator 3 , the phase modulator 4 , and the amplitude modulator 5 in accordance with the multilevel code output of the code generator 6 so as to transmit polarized waves at different angles. do.
変調を施された光束は、伝送媒体８を伝搬す°−４−′
る。伝搬した光束は偏光状態判定器９で偏光状態を検出
される。The modulated light beam propagates through the transmission medium 8. The polarization state of the propagated light beam is detected by a polarization state determiner 9.
局発光源１０は、可干渉性の光束を出力する。The local light source 10 outputs a coherent light beam.
偏光状態判定器９を通過した光束は干渉器１１においで
局発光源１０を出射した光束と干渉する。干渉した光束
は光検出器１２で電気信号に変換される。電気信号は周
波数判定器１３で周波数判定される。周波数判定器１３
を通過した電気信号は位相判定器１４で位相判定される
。The light beam that has passed through the polarization state determiner 9 interferes with the light beam emitted from the local light source 10 in an interferometer 11 . The interfering light beams are converted into electrical signals by the photodetector 12. The frequency of the electrical signal is determined by a frequency determiner 13. Frequency determiner 13
The phase of the electrical signal that has passed is determined by a phase determiner 14.
位相判定器１４の出力は振幅判定器１５で振幅判定され
る。符号判定器１６は偏光状態判定器９、周波数判定器
１３、位相判定器１４および振幅判定器１５の出力をも
とに符号判定する。The amplitude of the output of the phase determiner 14 is determined by an amplitude determiner 15. The sign determiner 16 determines the sign based on the outputs of the polarization state determiner 9, the frequency determiner 13, the phase determiner 14, and the amplitude determiner 15.
符号再生器１７は符号判定器１６の出力を用いて符号列
を再生する。The code regenerator 17 uses the output of the code determiner 16 to reproduce the code string.
本実施例は、伝送しようとする情報に対応して、光源１
を出射した光束を信号制御器７の出力に従って偏光状態
変調器２、周波数変調器３、位相変調器４および振幅変
調器５を用いて、偏光状態変調、周波数変調、位相変調
および振幅変調し、伝送媒体８を介して遠隔地に伝送し
、この伝送された光束を偏光状態判定器９を用いて偏光
状態を判定し、偏光状態判定器９を通過した光束と局発
光源１０がらの光束とを干渉させ、さらに、周波数判定
器１３、位相判定器１４および振幅変調器１５を用いて
周波数、位相および振幅を判定し、符号再生器１７を用
いて符号列を再生している。In this embodiment, the light source 1
The emitted light flux is subjected to polarization state modulation, frequency modulation, phase modulation and amplitude modulation using the polarization state modulator 2, frequency modulator 3, phase modulator 4 and amplitude modulator 5 according to the output of the signal controller 7, The transmitted light beam is transmitted to a remote location via a transmission medium 8, and the polarization state of the transmitted light beam is determined using a polarization state determiner 9, and the light beam that has passed through the polarization state determiner 9 and the light beam from the local light source 10 are separated. Further, the frequency, phase, and amplitude are determined using the frequency determiner 13, phase determiner 14, and amplitude modulator 15, and the code string is regenerated using the code regenerator 17.
そして、ヘテロゲイン検波を利用しているために伝送に
関与する周波数以外の周波数成分は雑音として除外され
ること、０．１の符号を用いた二値伝送に比べて偏光状
態、周波数、位相および振幅を符号要素として利用する
ため多値伝送が可能となり見かけの伝送速度以上に大き
な伝送速度で情報を伝送できること、また、偏光状態、
周波数、位相および振幅を符号要素として利用して多数
の符号を形成でき、これを用いて誤り訂正符号をも形成
できるため符号誤り率を減少せしめることができるなど
の特徴を有している。Furthermore, because heterogain detection is used, frequency components other than frequencies involved in transmission are excluded as noise, and compared to binary transmission using a code of 0.1, polarization state, frequency, phase, and amplitude are As a code element, multilevel transmission is possible, and information can be transmitted at a higher transmission speed than the apparent transmission speed.
It has the characteristics that a large number of codes can be formed using frequency, phase, and amplitude as code elements, and that it can also be used to form an error correction code, so that the code error rate can be reduced.
従って、大きな情報伝送速度で高品質の光伝送方式を得
ることができる。Therefore, it is possible to obtain a high quality optical transmission system with a high information transmission rate.
すなわち、伝送媒体として偏波保持ファイバを用いた場
合、その偏波保持ファイバの進相軸、遅相軸に一致した
互い直交する２つの直線偏光波を用い、周波数としてＦ
ＩｔＦ２ｆ・・・・・・Ｆｌｓ位相としてφ１．φ２．
・・・・・・ φ」、振幅Ａｌ１Ａ２・・・・・・ Ａ
ｍを用いれば、各々異なる符号を対応させることができ
、使用できる符号の種類２＋＋＋Ｊ＋ｍ
は２ 個となるため、伝送速度なｆ。とすると、
情報伝送速度■は次式で表わせる。In other words, when a polarization-maintaining fiber is used as a transmission medium, two mutually orthogonal linearly polarized waves that coincide with the fast and slow axes of the polarization-maintaining fiber are used, and the frequency is F.
ItF2f... φ1. as Fls phase. φ2.
...... φ", amplitude Al1A2...A
If m is used, different codes can be made to correspond to each other, and the number of usable code types 2+++J+m is two, so the transmission speed is f. Then,
The information transmission speed ■ can be expressed by the following equation.
Ｉ ＝ｆｏ Ｌｏｇ２（２＋ｉ＋ｊ＋ｍ） ・・・
・・・・・・・−（１，）偏光状態、周波数、位相ある
いは振幅のいずれか一つを用いて二値伝送する場合、式
（１）より、Ｉ＝ｆ、となり、本発明の方式の等測的情
報伝送速度の方が二値伝送の等測的情報伝送速度よりも
大きいことが明らかである。I =fo Log2(2+i+j+m)...
......-(1,) When performing binary transmission using any one of the polarization state, frequency, phase, or amplitude, from equation (1), I=f, and the method of the present invention It is clear that the isometric information transmission rate of is greater than that of binary transmission.
２＋＋＋ｊ＋ｍ
また、２ 個の符号のうち重複を許して符号を形
成することにより誤り訂正ＰＩｉ能を有する符号を形成
できる。2+++j+m Furthermore, by forming a code by allowing duplication among two codes, a code having error correction PIi capability can be formed.
−７−。-7-.
第２図は、本発明の本発明の第二の実施例の光伝送シス
テムの構成を示すブロック図である。FIG. 2 is a block diagram showing the configuration of an optical transmission system according to a second embodiment of the present invention.
第１図と異なるところは伝送媒体８がらの偏光波が干渉
器１１に入射すること、干渉器１１で形成された干渉波
が偏光状態判定器９に入射すること、偏光状態判定器９
の出力成分は光検出器１２に入射することである。The differences from FIG. 1 are that the polarized wave from the transmission medium 8 enters the interferometer 11, the interference wave formed by the interferometer 11 enters the polarization state determiner 9, and the polarization state determiner 9.
The output component of is incident on the photodetector 12.
第３図は本発明の第３の実施例の光伝送システムの構成
を示すブロック図である。FIG. 3 is a block diagram showing the configuration of an optical transmission system according to a third embodiment of the present invention.
ｆｔ５２図と異なるところは、局発光源１０を出射した
光束に偏光状態変調器１８により偏光状態を変調し変調
波を干渉器１１に入力すること、符号判定器１６は偏光
状態変調器１８を偏光状態判定器９と連動して制御する
ことである。The difference from the ft52 diagram is that the polarization state modulator 18 modulates the polarization state of the light beam emitted from the local light source 10 and the modulated wave is input to the interferometer 11, and the sign determiner 16 modulates the polarization state of the light beam emitted from the local light source 10 The control is performed in conjunction with the state determiner 9.
なお、偏光状態変調器２、周波数変調器３、位相変調器
４、振幅変調器５の光源からの順序は任意に変更して構
成してもよい。同様に、周波数判定器１３、位相判定器
１４、振幅判定器１５の伝送媒体８からの順序について
も任意に変更して構成しても良い。Note that the order of the polarization state modulator 2, frequency modulator 3, phase modulator 4, and amplitude modulator 5 from the light source may be changed arbitrarily. Similarly, the order of the frequency determiner 13, phase determiner 14, and amplitude determiner 15 from the transmission medium 8 may be changed arbitrarily.
’−８＝
さらに、光検出器１２から並列に周波数Ｎ定器１３、位
相判定器１４、振幅判定器１５を接続して構成してもよ
い。'-8= Furthermore, a frequency N determiner 13, a phase determiner 14, and an amplitude determiner 15 may be connected in parallel from the photodetector 12.
また、偏光状態変調器２、周波数変調器３、位相変調器
４、振幅変調器５のうち少なくとも二種類の変調器を用
いて構成し、それに対応して偏光状態判定器９、周波数
判定器１３、位相判定器１４、振幅判定器１５のうちか
ら必要な判定器を選択して構成することも、可能である
。Further, it is configured using at least two types of modulators among a polarization state modulator 2, a frequency modulator 3, a phase modulator 4, and an amplitude modulator 5, and a polarization state determiner 9 and a frequency determiner 13 correspondingly. , the phase determiner 14, and the amplitude determiner 15.
以上説明したように、本発明により情報伝送速度を大き
くし、高い符号誤り率を保持した大容量高品質の伝送方
式を実現できる。As explained above, according to the present invention, it is possible to realize a high-capacity, high-quality transmission system that increases the information transmission rate and maintains a high bit error rate.
本発明は、多値符号伝送が可能なので、基幹伝送方式の
みならず大容量伝送が要求される画像伝送、知能情報伝
送に大きな効果がある。Since the present invention enables multilevel code transmission, it is highly effective not only in basic transmission systems but also in image transmission and intelligent information transmission that require large-capacity transmission.
第１図は本発明の第一の実施例の光伝送システムのｍ戒
を示すブロック図、第２図は本発明の第二の実施例の光
伝送システムの構成を示すブロック図、ｆＩＳ３図は本
発明の第三の実施例の光伝送システムの構成を示すブロ
ック図である。
１ ・・・・・・光源、 ２．１８ ・・・・・・偏光
状態変調器、 ３ ・・・・・・周波数変調器、 ４
・・・・・・位相変調器、 ５ ・・・・・・ 振幅変
調器、 ６ ・・・・・・符号発生器、 ７ ・・・・
・・符号制御器、 ８・・・・・・伝送媒体、 ９ ・
・・・・・偏光状態判定器、１０ ・・・・・・局発光
源、 １１ ・・・・・・干渉器、１２ ・・・・・・
光検出器、 １３ ・・・・・・ 周波数判定器、
１４ ・・・・・・位相判定器、 １５ ・・・・
・・振幅判定器、 １６ ・・・・・・符号判定器、
１７・・・・・・符号再生器FIG. 1 is a block diagram showing the configuration of the optical transmission system according to the first embodiment of the present invention, FIG. 2 is a block diagram showing the configuration of the optical transmission system according to the second embodiment of the present invention, and the fIS3 diagram is FIG. 3 is a block diagram showing the configuration of an optical transmission system according to a third embodiment of the present invention. 1...Light source, 2.18...Polarization state modulator, 3...Frequency modulator, 4
...Phase modulator, 5 ...Amplitude modulator, 6 ...Code generator, 7 ...
... code controller, 8 ... transmission medium, 9.
...Polarization state determiner, 10 ...Local light source, 11 ...Interferometer, 12 ......
Photodetector, 13... Frequency determiner,
14... Phase determiner, 15...
...amplitude determiner, 16... sign determiner,
17... Code regenerator
Claims (1)
偏光波に変換する手段と、光束を振幅と偏光状態および
位相が同一で周波数が二種類あるいはそれ以上の異なる
偏光波に変換する手段と、光束を振幅と偏光状態および
周波数が同一で二種類あるいはそれ以上の異なる位相の
偏光波に変換する手段と、光束を偏光状態と周波数およ
び位相が同一で二種類あるいはそれ以上の異なる振幅の
偏光波に変換する手段と、これらの偏光波のうちの二種
類あるいはそれ以上の偏光波を人為的に形成した符号列
に対応付ける手段と、これらの偏光波の一つを選択し時
系列的に並んだ偏光波の列として伝送媒体に入射する手
段と、該伝送媒体から出射した時系列的に並んだ偏光波
の列に局発光源から出射した光束を合波して干渉波を形
成する手段と、一つの偏光波を選択し選択した偏光波を
人為的に形成された情報として再現する手段とを具備す
る系によって、空間的に隔たった場所に情報を伝送する
ことを特徴とする光伝送方式。means for converting a luminous flux into polarized waves having the same amplitude, frequency, and phase and orthogonal to each other; means for converting the luminous flux into polarized waves having the same amplitude, polarization state, and phase, and two or more different frequencies; into two or more different phases of polarized waves with the same amplitude, polarization state, and frequency; means for converting, means for associating two or more of these polarized waves with an artificially formed code string, and selecting one of these polarized waves and chronologically arranging the polarized waves. means for inputting a wave train into a transmission medium; and means for combining a light beam emitted from a local light source with a time-series sequence of polarized waves emitted from the transmission medium to form an interference wave. An optical transmission system characterized by transmitting information to a spatially separated location using a system comprising means for selecting one polarized light wave and reproducing the selected polarized light wave as artificially formed information.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP61207710A JPS6364418A (en) | 1986-09-05 | 1986-09-05 | Light transmission system |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP61207710A JPS6364418A (en) | 1986-09-05 | 1986-09-05 | Light transmission system |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| JPS6364418A true JPS6364418A (en) | 1988-03-22 |
Family
ID=16544279
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP61207710A Pending JPS6364418A (en) | 1986-09-05 | 1986-09-05 | Light transmission system |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JPS6364418A (en) |
Cited By (8)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPH03263933A (en) * | 1990-03-14 | 1991-11-25 | Matsushita Electric Ind Co Ltd | Coherent optical transmission equipment |
| US5526162A (en) * | 1994-09-27 | 1996-06-11 | At&T Corp. | Synchronous polarization and phase modulation for improved performance of optical transmission systems |
| US5663824A (en) * | 1993-11-02 | 1997-09-02 | Lucent Technologies Inc. | Optical modulators as monolithically integrated optical isolators |
| US5946119A (en) * | 1997-02-12 | 1999-08-31 | Tyco Submarine Systems Ltd. | Wavelength division multiplexed system employing optimal channel modulation |
| US6421155B1 (en) | 1997-05-28 | 2002-07-16 | Nec Corporation | Optical data transmitting apparatus and method |
| JP2011223258A (en) * | 2010-04-08 | 2011-11-04 | Nippon Telegr & Teleph Corp <Ntt> | Optical transmission method, optical transmission system, optical transmitter, and optical receiver |
| JP2013081139A (en) * | 2011-10-05 | 2013-05-02 | Kddi Corp | Optical transmission system and transmission method, using a combination of polarization modulation and frequency modulation |
| JP2014171194A (en) * | 2013-03-05 | 2014-09-18 | Nippon Telegr & Teleph Corp <Ntt> | Optical transmission system using wavelength variable light source |
-
1986
- 1986-09-05 JP JP61207710A patent/JPS6364418A/en active Pending
Cited By (9)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPH03263933A (en) * | 1990-03-14 | 1991-11-25 | Matsushita Electric Ind Co Ltd | Coherent optical transmission equipment |
| US5663824A (en) * | 1993-11-02 | 1997-09-02 | Lucent Technologies Inc. | Optical modulators as monolithically integrated optical isolators |
| US5526162A (en) * | 1994-09-27 | 1996-06-11 | At&T Corp. | Synchronous polarization and phase modulation for improved performance of optical transmission systems |
| US5912755A (en) * | 1994-09-27 | 1999-06-15 | Tyco Submarine Systems Ltd. | Synchronous polarization and phase modulation for improved performance of optical transmission systems |
| US5946119A (en) * | 1997-02-12 | 1999-08-31 | Tyco Submarine Systems Ltd. | Wavelength division multiplexed system employing optimal channel modulation |
| US6421155B1 (en) | 1997-05-28 | 2002-07-16 | Nec Corporation | Optical data transmitting apparatus and method |
| JP2011223258A (en) * | 2010-04-08 | 2011-11-04 | Nippon Telegr & Teleph Corp <Ntt> | Optical transmission method, optical transmission system, optical transmitter, and optical receiver |
| JP2013081139A (en) * | 2011-10-05 | 2013-05-02 | Kddi Corp | Optical transmission system and transmission method, using a combination of polarization modulation and frequency modulation |
| JP2014171194A (en) * | 2013-03-05 | 2014-09-18 | Nippon Telegr & Teleph Corp <Ntt> | Optical transmission system using wavelength variable light source |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| US5136666A (en) | Fiber optic communication method and apparatus providing mode multiplexing and holographic demultiplexing | |
| US4831663A (en) | Digital signal transmission/reception using differential polarization modulation/demondulation | |
| CA2193754C (en) | Synchronous polarization and phase modulation using a periodic waveform with complex harmonics for improved performance of optical transmission systems | |
| JP3094950B2 (en) | Optical transmission device and optical transmission method | |
| JPH03210841A (en) | Optical fiber communication system | |
| JPH02275411A (en) | High-speed modulator for changing the polarization state of optical carriers | |
| CN208797952U (en) | Polarization encoding device for optical communication | |
| JP2001147411A (en) | Light modulator | |
| JPH09236835A (en) | Adjustable optical amplitude phase modulator and soliton regenerator containing such modulator | |
| US5010586A (en) | Optical two-way transmission system with loop reflector modulator | |
| JPS6364418A (en) | Light transmission system | |
| JPS6313017A (en) | Optical amplitude and phase modulator | |
| US6535316B1 (en) | Generation of high-speed digital optical signals | |
| JPS6135032A (en) | Optical wave transmitting system using homodyne detection | |
| CN210839600U (en) | Quantum key distribution device and system | |
| US3743376A (en) | Holographic beam coupler | |
| JP2677289B2 (en) | Optical communication system | |
| US20070047668A1 (en) | Single side band modulator module and single side band modulator device using the same | |
| CN112804057B (en) | Continuous variable quantum key distribution Gaussian modulation implementation device and method | |
| JP4713142B2 (en) | Apparatus for reproducing optical signal, method of using the apparatus, and equipment equipped with the apparatus | |
| CN115225155A (en) | A system and method for realizing multi-channel co-carrier frequency phase encoding based on array structure | |
| JP3230522B2 (en) | Signal communication method | |
| JPS62247639A (en) | Optical signal transmission system | |
| JPH0661942A (en) | Optical transmission system | |
| US20060210283A1 (en) | Transmitters for inversely dispersed optical signals |