JPS589446A - Analog optical transmission device - Google Patents
Analog optical transmission deviceInfo
- Publication number
- JPS589446A JPS589446A JP56108746A JP10874681A JPS589446A JP S589446 A JPS589446 A JP S589446A JP 56108746 A JP56108746 A JP 56108746A JP 10874681 A JP10874681 A JP 10874681A JP S589446 A JPS589446 A JP S589446A
- Authority
- JP
- Japan
- Prior art keywords
- signal
- transmitted
- triangular wave
- frequency
- emitting element
- 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
- H04B10/501—Structural aspects
- H04B10/503—Laser transmitters
- H04B10/505—Laser transmitters using external modulation
- H04B10/5057—Laser transmitters using external modulation using a feedback signal generated by analysing the optical output
- H04B10/50572—Laser transmitters using external modulation using a feedback signal generated by analysing the optical output to control the modulating signal amplitude including amplitude distortion
-
- 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
- H04B10/501—Structural aspects
- H04B10/502—LED transmitters
-
- 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
- H04B10/501—Structural aspects
- H04B10/503—Laser transmitters
- H04B10/505—Laser transmitters using external modulation
-
- 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
- H04B10/58—Compensation for non-linear transmitter output
Landscapes
- Physics & Mathematics (AREA)
- Electromagnetism (AREA)
- Engineering & Computer Science (AREA)
- Computer Networks & Wireless Communication (AREA)
- Signal Processing (AREA)
- Optics & Photonics (AREA)
- Nonlinear Science (AREA)
- Optical Communication System (AREA)
Abstract
Description
【発明の詳細な説明】
この発明は、直接強度変調方式のアナログ光送信変換器
において、その精度、直接性を改良するものに関する。DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a direct intensity modulation type analog optical transmission converter that improves its accuracy and directness.
第１図に従来のアナログ光通信装置に用いられているア
ナログ光送信変換器の例を示す。＋ｌ＋は入力端子、（
２）は増巾器、１３）は発光素子、（４）は発光素子＋
３１の出力光、（６）は光分配器、（６）は（４）の一
部で変換器の出力光、（７）は（４）の一部で負帰還に
使用するために分妃された光、（８１は光検出器、（９
）は増巾器を示す。FIG. 1 shows an example of an analog optical transmission converter used in a conventional analog optical communication device. +l+ is the input terminal, (
2) is a amplifier, 13) is a light emitting element, (4) is a light emitting element +
31 output light, (6) is a light splitter, (6) is a part of (4) and is the output light of the converter, (7) is a part of (4) and is a splitter for use in negative feedback. (81 is a photodetector, (9
) indicates an amplifier.
入力端子ｆｉｌ ｌ／１１ｍは、送信しようとするアナ
ログ電気信号≠１加えられる。増巾器（２）は、これを
増巾して発光素子（３）に供給する。発光素子は、増巾
器の出力電気信号を光に変換するが、良く知られている
様に、出力光量と電気入力との比例性は十分でなく、光
信号は入力電気信号に対して歪を持っている。この現象
は、発光素子がレーザダイオードである場合に特に著し
い。この現象はディジタル信号の伝送にはあまり障害に
ならないガ、アナログ信号の伝送には、大きな障害とな
る。＋５１ 、 （７１、＋８１ 、 ＋９１は、この
発光素子の非直線性による光信号の歪を減小させるため
の負帰還路を形成している。光分配器＋５１ ｔｒｉ光
信号（４）の一部（７）を光検出器（８）に分配し、光
検出器に検出された光信号は増巾器（９１で増巾され、
増巾器（２１の入力端で入力信号から差し引かれる。The analog electrical signal to be transmitted≠1 is applied to the input terminal fil/11m. The amplifier (2) amplifies this and supplies it to the light emitting element (3). The light emitting element converts the output electrical signal of the amplifier into light, but as is well known, the proportionality between the amount of output light and the electrical input is insufficient, and the optical signal is distorted with respect to the input electrical signal. have. This phenomenon is particularly remarkable when the light emitting element is a laser diode. Although this phenomenon does not pose much of an obstacle to the transmission of digital signals, it becomes a major obstacle to the transmission of analog signals. +51, (71, +81, +91 form a negative feedback path to reduce the distortion of the optical signal due to the nonlinearity of this light emitting element. Part of the optical splitter +51 tri optical signal (4) (7) is distributed to a photodetector (8), and the optical signal detected by the photodetector is amplified by an amplifier (91).
It is subtracted from the input signal at the input of the amplifier (21).
ここで増巾器１２）または（９）の利得が十分に大きけ
れば、増巾器（９）の出力信号は入力信号とほぼ等しく
なる。光検出器（８１および増巾器（９）の直線性が良
く光分配器（５）の分配率が一定であれば、出力光（６
）は入力信号に比例したものとなり、前述の非直線性が
改善される。しかし、この負帰還′による非直線歪の改
善の程度は十分ではなく、特に、大きな負帰還量を与え
られない１゛高周波信号の変換器に於ては□、更に改良
する必要があった１゜
第２図は、第１図のものよりも改良された従来例を示し
ている。第１図の従来例と異るところは、高周波発振器
（１０１を付加したことである。Here, if the gain of the amplifier 12) or (9) is sufficiently large, the output signal of the amplifier (9) will be approximately equal to the input signal. If the photodetector (81) and amplifier (9) have good linearity and the distribution ratio of the optical distributor (5) is constant, the output light (6
) becomes proportional to the input signal, and the above-mentioned nonlinearity is improved. However, the degree of improvement in nonlinear distortion caused by this negative feedback was not sufficient, and in particular, in converters for high-frequency signals that cannot provide a large amount of negative feedback, further improvements were needed. 2 shows a conventional example which is improved over that shown in FIG. The difference from the conventional example shown in FIG. 1 is that a high frequency oscillator (101) is added.
高周波発振器は、被伝送信号の周波数上限より高い周波
数の正弦波を発生し、これを増巾器（２）゛の出力信号
に重畳させて発光素子（３）に与える。The high frequency oscillator generates a sine wave with a frequency higher than the upper limit of the frequency of the transmitted signal, superimposes this on the output signal of the amplifier (2), and supplies it to the light emitting element (3).
この高周波信号は、発光素子の入出力特性が線高間波信
号を除去すれば、被伝送信号のみが復元される。If the input/output characteristics of the light emitting element eliminate the line high frequency signal, only the transmitted signal will be restored.
ここで、発光素子に非線形性が有る場合の作用を考える
と、発光素子の入出力特性上の非線形となる動作点の悪
影響が高周波信号の重畳によって分散され、後に高周波
信号を除去すれば、鋭いキンクやジャンプの緩和された
信号が得られ、負帰還ループによる信号の修正がしやす
くなる。ただし、負帰還ループの応答周波数は、重畳さ
れた高周波信号に追従するほど高い必要はなく、被伝送
信号の帯域をカバーできれば良い。この第２の従来例は
、オｌのものに比べ１て改良されてはいるが、重畳する
高周波信号が正弦波であれために、重畳波形の電圧対滞
在時間率分布が、包絡線の上限と下限に集中しており、
前述の分散効果があまり大きくない。そのため、この方
法によっても、従来は高精度、高品位なアナログ信号の
伝送は困難とされ高精度伝送には、他のもつと複雑な回
路を必要とする変調方式、例えばＰ Ｆ Ｍ （ｐｕｌ
ｓｅ ｆｒｅｑｕｅｎｃｙ ｍｏｄｕｌａｔｉｏｎ１方
式等が必要とされていた。Here, considering the effect when the light emitting element has nonlinearity, the adverse effect of the nonlinear operating point on the input/output characteristics of the light emitting element is dispersed by the superposition of a high frequency signal, and if the high frequency signal is removed later, the effect becomes sharp. A signal with reduced kinks and jumps can be obtained, making it easier to modify the signal using a negative feedback loop. However, the response frequency of the negative feedback loop does not need to be high enough to follow the superimposed high-frequency signal, but only needs to cover the band of the transmitted signal. Although this second conventional example is improved over the first one, since the high-frequency signal to be superimposed is a sine wave, the voltage versus residence time ratio distribution of the superimposed waveform is at the upper limit of the envelope. and are concentrated at the lower limit,
The aforementioned dispersion effect is not very large. Therefore, even with this method, it has traditionally been difficult to transmit high-precision, high-quality analog signals, and for high-precision transmission, other modulation methods that require complex circuits, such as PFM (pulver
A se frequency modulation 1 method was required.
この発明は、従来技術の前述の欠点を改良し、回路が簡
単で信頼性の高い直接強度変調方式に高い精度を与え、
すぐれたアナログ光通信装置を提供しようとするもので
ある。The present invention improves the above-mentioned drawbacks of the prior art, provides a simple circuit, reliable direct intensity modulation method with high accuracy,
The aim is to provide an excellent analog optical communication device.
第８図に、本発明による光送信変換器の一実施例の構成
図を示す。ｆｉ＋は入力端子、（２）は増巾器、（３）
は発光素子、（４）け発光素子（３）の出力光、（５）
は光分配器、（６）は（４］の一部で変換器の出力光、
（７）は（４）の一部で、９帰に使用するだめに分配し
た光、（８１け光検出器、（９）は増巾器、 ＋１αは
三角波発振器、’ Ｑｔ）は変調器である。FIG. 8 shows a configuration diagram of an embodiment of an optical transmission converter according to the present invention. fi+ is the input terminal, (2) is the amplifier, (3)
is the light emitting element, (4) is the output light of the light emitting element (3), (5)
is a light splitter, (6) is a part of (4) and is the output light of the converter,
(7) is a part of (4), and the light distributed to the 9th wave, (81 photodetectors, (9) is an amplifier, +1α is a triangular wave oscillator, and 'Qt) is a modulator. be.
被伝送信号は、入力端子ｆｉｌ Ｋ与えられ、増巾器（
２）で増巾され、変調器（ＩＩ）に与えられる°。三角
波発生器（１αけ、被伝送信号の周波数上限より高い周
波数の三角波を、変調信号として変調器（＋１に与える
１゜変調器は、被伝送信号に、被伝送信号と三角波の積
を加えて出力する。牙４図に、変調器の入出力関係を示
す。第４図（ａ、）は被伝送信号Ｃ被変調信号）、ｔｂ
ｌは変調信号Ｃ三角波）、回は変調出力信号を示す。被
伝送信号にこの様な変調を加えると、変調信号波形が三
角波であるため、変調出力信号の電圧対滞在時間率分布
が変調振巾区間内で一様となり、第２の従来例にくらべ
て、発光素子の非直線性の分散効果が大きい。そのため
、負帰還ループによる信号の修正が著るしく容易になり
、精度の高い電気−光信号変換が可能になっている。The signal to be transmitted is given to the input terminal fil K, and is passed through the amplifier (
2) and fed to the modulator (II). A triangular wave generator (by 1α, a triangular wave with a frequency higher than the upper limit of the frequency of the transmitted signal is applied to the modulator (+1) as a modulation signal.The 1° modulator adds the product of the transmitted signal and the triangular wave to the transmitted signal. Figure 4 shows the input/output relationship of the modulator. Figure 4 (a) shows the transmitted signal (C modulated signal), tb
1 is the modulation signal C triangular wave), and times are the modulation output signal. When such modulation is applied to the transmitted signal, since the modulation signal waveform is a triangular wave, the voltage vs. residence time ratio distribution of the modulated output signal becomes uniform within the modulation amplitude section, and compared to the second conventional example. , the nonlinear dispersion effect of the light emitting element is large. Therefore, signal correction by the negative feedback loop becomes significantly easier, and highly accurate electrical-to-optical signal conversion becomes possible.
また、この実施例では第２の実施例と異り、被伝送信号
に対して三角波を加えるのではなく、被伝送信号と三角
波の積を加える形の変調を行っているので、被伝送信号
の振巾に関係なく一定の変調率が得られる。この性質は
、被伝送信号のダイナミックレンジが大きい場合に、そ
れに対処するための調整が不要であわ、受信時の復調に
於て、変開波の除去の負担が自動的に最小となる利点か
ある。Also, unlike the second embodiment, this embodiment modulates the transmitted signal by adding the product of the transmitted signal and the triangular wave, rather than adding a triangular wave to the transmitted signal. A constant modulation rate can be obtained regardless of amplitude. This property has the advantage that when the dynamic range of the transmitted signal is large, there is no need to make adjustments to deal with it, and the burden of removing the spread wave during reception is automatically minimized. be.
第５図は、第８図に示した実施例を、より具体的に示し
たものである。この実施例では、変調器（１１）として
、トランジスタによるエミッタ結合電流分配器を用いて
いる゛。増巾器（２）は電流出力型であるか、または電
圧出力型増巾器の出力端に直列に抵抗器を挿入したもの
である。市浦分配器の動作は、第５図（１１）に示した
符号を用いて次の様に表わせる。FIG. 5 shows the embodiment shown in FIG. 8 in more detail. In this embodiment, an emitter-coupled current divider using a transistor is used as the modulator (11). The amplifier (2) is of a current output type or a voltage output type amplifier with a resistor inserted in series at the output end. The operation of the Ichiura distributor can be expressed as follows using the symbols shown in FIG. 5 (11).
Ｉｌ 中 Ｔｓ Ｃ１＋ ｋ Ｖ ）工雪中Ｉ
Ｂ（１−ｋｖ）
上の式から判る様に、変調信号ｌ１は被変調信号工。に
、■。と変調信号■との積を加えたものとなっている。Il middle Ts C1+ k V) Snow construction middle I
B(1-kv) As can be seen from the above equation, the modulated signal l1 is a modulated signal. To, ■. and the modulation signal ■.
（■け交番信号なので、ここでは極性は無視している。(Since it is a police box signal, the polarity is ignored here.
）
ｆ調強度け、ｆ調信号Ｖの振巾によって任意に調節でき
る。定数にの値は通常の宕稲では約１９（Ｖ−１１であ
るから、変調信号の振巾が±１０ｍｖのとき、変調率が
±１９％となる。変調率が大きい場合は前出の式の近似
誤差が大きくなり、変調出力信号の波形も好ましくない
変形を示すので、変調率は、±５０％以内に設定するこ
とが望ましい。) It can be arbitrarily adjusted by adjusting the f-key strength and the amplitude of the f-key signal V. The value of the constant is approximately 19 (V-11) for normal Miyama rice, so when the amplitude of the modulation signal is ±10mV, the modulation rate is ±19%.If the modulation rate is large, the above formula The approximation error becomes large and the waveform of the modulated output signal also exhibits undesirable deformation, so it is desirable to set the modulation rate within ±50%.
この実施例に用いている変調器は、構造が簡単で、応答
速度が早く、１００ＭＨ，以上まで使用でき、変調信号
が小さくてすむ等利点が多い。The modulator used in this embodiment has many advantages such as simple structure, fast response speed, can be used up to 100 MHz or more, and only requires a small modulation signal.
以上の説明で明らかな様に、この発明の方式によれば、
簡単な装置で従来例の欠点を大巾に改良した高精度、旨
品位のアナログ光通信装置を１是供することができる。As is clear from the above explanation, according to the method of this invention,
With a simple device, it is possible to provide a high-precision, high-quality analog optical communication device that greatly improves the drawbacks of the conventional example.
また、実施例に於てけ変調器を用いているが、単に三角
波を重畳するだけでも、正弦波と三角波の波形の遠いに
もとすく改良効果は得られ乙ので、被伝送信号のダイナ
ミックレンジが小さい場合は、変調器を用いないでも良
い。In addition, although a modulator is used in the embodiment, simply superimposing a triangular wave can quickly improve the distance between the sine wave and triangular waveforms, so the dynamic range of the transmitted signal can be improved. If it is small, no modulator may be used.
オ１図、第２図は従来のアナログ光通信装置に用いられ
るアナログ光送信変換器の構成図、牙８図はこの発明の
アナログ光通信装置に用いられるアナログ光送信変換器
の一実施例を示す構成図、牙４図は変調器の入出力関係
を示す図、第５図は牙８図に示した実施例をより具体的
に示した構成図である。
図中、（１）は入力端子、＋２１は増巾器、１３）け発
光素子、（５）は光分配器、（８１け光検出器、（９）
は増巾器、（１αは三角波発振器、 （ＩＩ）は変調器
、である。
なお、図中同一符号は同−又は相当部分を示す゛。
代理人 葛 野 信 −
第１図
第２図Figures 1 and 2 are block diagrams of an analog optical transmission converter used in a conventional analog optical communication device, and Figure 8 shows an embodiment of an analog optical transmission converter used in the analog optical communication device of the present invention. FIG. 5 is a block diagram showing the embodiment shown in FIG. 8 in more detail. In the figure, (1) is the input terminal, +21 is the amplifier, 13) is the light emitting element, (5) is the optical distributor, (81 is the photodetector, (9)
is an amplifier, (1α is a triangular wave oscillator, and (II) is a modulator. In addition, the same reference numerals in the figures indicate the same or corresponding parts. Agent Shin Kuzuno - Figure 1 Figure 2
Claims (2)
備え、その発光素子の入力電流を、伝送する信号の周波
数より高い周波数を有する三角波でｆ調したことを特徴
とするアナログ光通信装置。(1) An analog optical communication device comprising a direct intensity modulation type analog optical transmission converter, wherein the input current of the light emitting element is f-tuned by a triangular wave having a frequency higher than the frequency of the signal to be transmitted.
数より高い周波数を有する三角波を重畳したことを特徴
とする特許請求の範囲牙１項記載のアナログ光通信装置
。 １３１ ’！１Ｈｉｉｌ装置としてエミッタ結合型電
流分配回路を用いたことを特徴とする特許請求の範囲牙
１項記載のアナログ光通信装置。(2) The analog optical communication device according to claim 1, wherein a triangular wave having a frequency higher than the frequency of the signal to be transmitted is superimposed on the input current of the light emitting element. 131'! 2. The analog optical communication device according to claim 1, wherein an emitter-coupled current distribution circuit is used as the 1Hil device.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP56108746A JPS589446A (en) | 1981-07-09 | 1981-07-09 | Analog optical transmission device |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP56108746A JPS589446A (en) | 1981-07-09 | 1981-07-09 | Analog optical transmission device |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JPS589446A true JPS589446A (en) | 1983-01-19 |
| JPS624900B2 JPS624900B2 (en) | 1987-02-02 |
Family
ID=14492456
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP56108746A Granted JPS589446A (en) | 1981-07-09 | 1981-07-09 | Analog optical transmission device |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JPS589446A (en) |
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US5046138A (en) * | 1989-06-26 | 1991-09-03 | General Instrument Corporation | Self-aligning analog laser transmitter |
| US5430569A (en) * | 1992-05-22 | 1995-07-04 | Ortel Corporation | Suppression of noise and distortion in fiber-optic systems |
Families Citing this family (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPH0165000U (en) * | 1987-10-16 | 1989-04-26 |
Citations (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS54144104A (en) * | 1978-04-28 | 1979-11-10 | Toshihiko Kotsukawa | Optical information transmission system |
-
1981
- 1981-07-09 JP JP56108746A patent/JPS589446A/en active Granted
Patent Citations (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS54144104A (en) * | 1978-04-28 | 1979-11-10 | Toshihiko Kotsukawa | Optical information transmission system |
Cited By (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US5046138A (en) * | 1989-06-26 | 1991-09-03 | General Instrument Corporation | Self-aligning analog laser transmitter |
| US5430569A (en) * | 1992-05-22 | 1995-07-04 | Ortel Corporation | Suppression of noise and distortion in fiber-optic systems |
| US5453868A (en) * | 1992-05-22 | 1995-09-26 | Ortel Corporation | Suppression of noise and distortion in fiber-optic systems |
Also Published As
| Publication number | Publication date |
|---|---|
| JPS624900B2 (en) | 1987-02-02 |
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