JPH01214081A - Laser diode driving circuit - Google Patents

Laser diode driving circuit

Info

Publication number
JPH01214081A
JPH01214081A JP63039281A JP3928188A JPH01214081A JP H01214081 A JPH01214081 A JP H01214081A JP 63039281 A JP63039281 A JP 63039281A JP 3928188 A JP3928188 A JP 3928188A JP H01214081 A JPH01214081 A JP H01214081A
Authority
JP
Japan
Prior art keywords
laser diode
resistor
output
matching
circuit
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
Application number
JP63039281A
Other languages
Japanese (ja)
Inventor
Kazuo Yamane
一雄 山根
Masanori Shimasue
政憲 嶌末
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Fujitsu Ltd
Original Assignee
Fujitsu Ltd
Priority date (The priority date 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 date listed.)
Filing date
Publication date
Application filed by Fujitsu Ltd filed Critical Fujitsu Ltd
Priority to JP63039281A priority Critical patent/JPH01214081A/en
Publication of JPH01214081A publication Critical patent/JPH01214081A/en
Pending legal-status Critical Current

Links

Classifications

    • HELECTRICITY
    • H01ELECTRIC ELEMENTS
    • H01SDEVICES USING THE PROCESS OF LIGHT AMPLIFICATION BY STIMULATED EMISSION OF RADIATION [LASER] TO AMPLIFY OR GENERATE LIGHT; DEVICES USING STIMULATED EMISSION OF ELECTROMAGNETIC RADIATION IN WAVE RANGES OTHER THAN OPTICAL
    • H01S5/00Semiconductor lasers
    • H01S5/04Processes or apparatus for excitation, e.g. pumping, e.g. by electron beams
    • H01S5/042Electrical excitation ; Circuits therefor

Landscapes

  • Physics & Mathematics (AREA)
  • Condensed Matter Physics & Semiconductors (AREA)
  • General Physics & Mathematics (AREA)
  • Electromagnetism (AREA)
  • Optics & Photonics (AREA)
  • Semiconductor Lasers (AREA)
  • Optical Communication System (AREA)

Abstract

PURPOSE:To facilitate connection between an LD and a driving device with a free distance by a method wherein a matching circuit composed of a capacitor and a resistor is provided at the output end of a driving part and the input end of the LD is connected to the LD through a series matching resistor and the output end of the driving part is connected to the input end of the LD with a transmission line having a characteristic impedance. CONSTITUTION:In a circuit which drives a laser diode (LD) 13 by the output of a driving part 10, a matching circuit 11 composed of a capacitor and a resistor is provided at the output end 100 of the driving part and the input end 130 of the LD 13 is connected to the LD 13 through a series matching resistor 14 and the output end 100 of the driving part 10 is connected to the input end 130 of the LD 13 with a transmission line 12 such as a coaxial cable and a microstrip line which has a characteristic impedance. For instance, an input signal is supplied to the base of a transistor 20 and a driving force is outputted from the collector of a transistor 21. The matching of the output is provided by a resistor 22 and a capacitor 23 and transmitted to the side of an LD 26 through a coaxial cable 27 and drives the LD 26 through a series matching resistor 25.

Description

【発明の詳細な説明】 [4既要コ 光通信の送信機等に用いられるレーザ・ダイオード駆動
回路に関し、 レーザ・ダイオードと駆動素子の間を自由な距離にして
接続を可能にするレーザ・ダイオード駆動回路を提供す
ることを目的とし、 駆動部の出力によりレーザ・ダイオードを駆動する回路
において、駆動部の出力端にコンデンサと抵抗から成る
整合回路を設け、レーザ・ダイオードの入力端とレーザ
・ダイオードとを直列の整合用抵抗を介して接続し、該
駆動部の出力端とレーザ・ダイオードの入力端の間を同
軸ケーブル、マイクロストリップライン等の特性インピ
ーダンスを有する伝送線路により接続するよう構成する
[Detailed Description of the Invention] [4]Regarding a laser diode drive circuit used in an optical communication transmitter, etc., a laser diode that enables connection with a free distance between the laser diode and the drive element. In a circuit that drives a laser diode using the output of the driver, a matching circuit consisting of a capacitor and a resistor is provided at the output end of the driver, and the input end of the laser diode and the laser diode are connected to each other. are connected through a series matching resistor, and the output end of the drive section and the input end of the laser diode are connected by a transmission line having a characteristic impedance such as a coaxial cable or a microstrip line.

[産業上の利用分野] 本発明は光通信の送信機等に用いられるレーザ・ダイオ
ード駆動回路に関する。
[Industrial Application Field] The present invention relates to a laser diode drive circuit used in optical communication transmitters and the like.

近年、光通信の伝送量の大容量化、伝送速度の高速化が
進み、速度としてはギガビット/秒のオーダーでレーザ
・ダイオードをオン・オフすることが行われるようにな
った。
In recent years, the transmission capacity and transmission speed of optical communications have increased, and laser diodes can now be turned on and off at speeds on the order of gigabits/second.

このような速度では、各素子間を接続する線路長が重大
な影響を与え、特にレーザ・ダイオードを駆動する素子
とこの駆動出力を受は取るレーザ・ダイオードの間を短
かくする必要があるのに対し、レーザ・ダイオードの特
性の向上や安定化のための回路素子を近接して設けなけ
ればならない等の事情により、距離を短(することが困
難となっており、その改善が望まれている。
At such speeds, the length of the line connecting each element has a significant effect, and in particular the distance between the element that drives the laser diode and the laser diode that receives this drive output must be kept short. However, due to circumstances such as improving the characteristics of laser diodes and the need to place circuit elements close together for stabilization, it has become difficult to shorten the distance, and improvements are desired. There is.

[従来の技術] 第3図に従来例の構成図を示す。[Conventional technology] FIG. 3 shows a configuration diagram of a conventional example.

第3図において、駆動素子(トランジスタ)からの出力
は出力端子31から接続&iLを介して入力端子32に
供給され、その入力を電流源としてレーザ・ダイオード
33が駆動される。
In FIG. 3, the output from the driving element (transistor) is supplied from an output terminal 31 to an input terminal 32 via a connection &iL, and a laser diode 33 is driven using the input as a current source.

この第3図の構成を実際に搭載した装置では、トランジ
スタにより構成された駆動素子30の出力はプリン)1
機上のラウンドに接続され、プリント配線である長さl
の線mLを通ってレーザ・ダイオードの駆動端子に接続
される。
In a device actually equipped with the configuration shown in FIG. 3, the output of the drive element 30 composed of transistors is 1)
Length l which is connected to the round on the machine and is a printed wiring
is connected to the drive terminal of the laser diode through the line mL.

上記の駆動素子30の出力端子31とレーザ・ダイオー
ド33の駆動端子32の距離は、伝送速度が上がるにつ
れて短くする必要があり、可能であれば駆動素子30の
出力を直接レーザ・ダイオードの駆動端子に接続したい
が、プリント基板に搭載する必要上、プリント配線によ
る接続線りを介して両者は接続される。
The distance between the output terminal 31 of the drive element 30 and the drive terminal 32 of the laser diode 33 needs to be shortened as the transmission speed increases, and if possible, the output of the drive element 30 can be directly connected to the drive terminal of the laser diode. However, since it needs to be mounted on a printed circuit board, the two are connected via printed wiring.

[発明が解決しようとする課題] 従来の構成によれば、伝送速度が低い場合は駆動素子と
レーザ・ダイオードの距離があまり問題にならなかった
が、近年は伝送速度が高速化し、GHz  (ギガヘル
ツ)の速度が用いられる。
[Problem to be solved by the invention] According to the conventional configuration, the distance between the drive element and the laser diode did not matter much when the transmission speed was low, but in recent years, the transmission speed has increased to GHz (gigahertz). ) is used.

この場合、上記の駆動素子とレーザ・ダイオード間を結
ぶ線路りの長さ2は極めて短くする必要があり、具体例
を挙げると、伝送速度IGHz(ギガヘルツ)の場合で
は約8mm(ミリメートル)であり、2GHzでは約4
mmとなる。
In this case, the length 2 of the line connecting the drive element and the laser diode described above needs to be extremely short; for example, in the case of a transmission speed of IGHz (gigahertz), it is approximately 8 mm (millimeters). , about 4 at 2GHz
It becomes mm.

ところが、このようにレーザ・ダイオードの変調速度限
界に近い高速度の変調を行う場合には、種々の補償回路
や、レーザ・ダイオードの温度制御回路などを設けるこ
とが必要になったが、それらの回路はレーザ・ダイオー
ドの近傍に設けなければならないので、配線が輻較し関
連する全回路を上記具体例で挙げたような、短距離り内
に接続することが困難となってきた。
However, when performing high-speed modulation close to the laser diode's modulation speed limit, it has become necessary to provide various compensation circuits and laser diode temperature control circuits, but these Since the circuit must be placed in the vicinity of the laser diode, the wiring becomes congested, making it difficult to connect all the related circuits within a short distance as in the specific example above.

本発明は、レーザ・ダイオードと駆動素子の間を自由な
距離にして接続を可能にするレーザ・ダイオード駆動回
路を提供することを目的とする。
SUMMARY OF THE INVENTION An object of the present invention is to provide a laser diode drive circuit that allows connection between a laser diode and a drive element at a free distance.

[課題を解決するための手段] 本発明の基本的構成図を第1図に示す。[Means to solve the problem] A basic configuration diagram of the present invention is shown in FIG.

第1図において、10は駆動部、11は整合回路、12
は伝送線路、13はレーザ・ダイオード、14は整合用
抵抗を表す。
In FIG. 1, 10 is a drive section, 11 is a matching circuit, and 12
13 represents a transmission line, 13 represents a laser diode, and 14 represents a matching resistor.

本発明は、普通のレーザ・ダイオードの交流インピーダ
ンスが数オームであるからそのままでは通常の伝送線路
(特性インピーダンス50Ωまたは75Ω)と整合をと
ることができないので、レーザ・ダイオード13と直列
の整合用抵抗14を挿入し、その値を調整して伝送線路
との整合をとり、駆動側と伝送線路とはコンデンサと抵
抗による整合回路11により整合をとる。
Since the alternating current impedance of a normal laser diode is several ohms, it cannot be matched with a normal transmission line (characteristic impedance 50Ω or 75Ω), so a matching resistor in series with the laser diode 13 is used. 14 is inserted and its value is adjusted to achieve matching with the transmission line, and the driving side and the transmission line are matched by a matching circuit 11 consisting of a capacitor and a resistor.

また、伝送線路12としては同軸ケーブルやマイクロス
トリップ等の特性インピーダンスを有する線路を用いる
Further, as the transmission line 12, a line having characteristic impedance such as a coaxial cable or a microstrip is used.

[作用] 駆動部10において高速度の送信信号を増幅して出力さ
れ、その出力は整合回路11において伝送線路12の特
性インピーダンスと整合され、伝送線路12を介してレ
ーザ・ダイオード側に達し、その抵抗14とレーザ・ダ
イオード13のインピーダンスが伝送線路12の特性イ
ンピーダンスと整合がとられて、レーザ・ダイオードを
駆動する。
[Function] A high-speed transmission signal is amplified and outputted in the drive unit 10, and the output is matched with the characteristic impedance of the transmission line 12 in the matching circuit 11, reaches the laser diode side via the transmission line 12, and its output is The impedance of resistor 14 and laser diode 13 is matched to the characteristic impedance of transmission line 12 to drive the laser diode.

[実施例] 第2図fa)に本発明の実施例1の構成図が示されてい
る。
[Embodiment] FIG. 2fa) shows a configuration diagram of a first embodiment of the present invention.

図において、20,21はバイポーラ型のトランジスタ
、22.23は整合回路を構成する抵抗とコンデンサ、
25は整合用抵抗、26はレーザ・ダイオード、27は
同軸ケーブルを表す。
In the figure, 20 and 21 are bipolar transistors, 22 and 23 are resistors and capacitors that constitute a matching circuit,
25 is a matching resistor, 26 is a laser diode, and 27 is a coaxial cable.

入力信号がトランジスタ20のベースに供給され、トラ
ンジスタ21のコレクタから駆動出力が発生する。その
出力は抵抗22とコンデンサ23により整合がとられ、
同軸ケーブル27を介してレーザ・ダイオード側に伝送
され、直列の整合用抵抗25を介してレーザ・ダイオー
ド26を駆動する。 同軸ケーブルの特性インピーダン
スを50オームとすると、レーザ・ダイオードの抵抗は
小さく数オームであるから整合用抵抗25は40数オ一
ム程度の値となる。また、整合回路のコンデンサ23は
IGHzの速度の特約18000pFのものを使用する
An input signal is applied to the base of transistor 20, and a drive output is generated from the collector of transistor 21. The output is matched by a resistor 22 and a capacitor 23,
The signal is transmitted to the laser diode side via the coaxial cable 27 and drives the laser diode 26 via the matching resistor 25 in series. If the characteristic impedance of the coaxial cable is 50 ohms, the resistance of the laser diode is small and is several ohms, so the matching resistor 25 has a value of about 40 ohms. Further, as the capacitor 23 of the matching circuit, a capacitor having a speed of about 18,000 pF is used.

次に本発明の実施例2の構成図を第2図山)に示す。Next, a configuration diagram of a second embodiment of the present invention is shown in FIG.

図において、40はFE”11ランジスタ、41.42
は整合回路を構成する抵抗とコンデンサ、43は整合用
抵抗、44はレーザ・ダイオード、45は同軸ケーブル
を表す。
In the figure, 40 is an FE"11 transistor, 41.42
43 represents a matching resistor, 44 represents a laser diode, and 45 represents a coaxial cable.

この実施例2の構成は駆動部のトランジスタがFET)
ランジスタを使用する点で実施例1と相違するが、その
動作は第2図(alの場合と同様である。
In the configuration of Example 2, the transistor in the drive section is an FET)
Although this embodiment differs from the first embodiment in that transistors are used, its operation is similar to that in FIG. 2 (al).

本発明をプリント基板(PTで表示)上の回路に適用し
た例を第2図(C1に示す。
An example in which the present invention is applied to a circuit on a printed circuit board (indicated by PT) is shown in FIG. 2 (C1).

図の50はレーザ・ダイオードの回路(LDで表示)、
51は駆動部のトランジスタ回路(TRで表示)を表し
、TRの出力端子53とLDの入力端子52にはコネク
タが設けられ、そのコネクタにより同軸ケーブル54が
接続され、両者の距離を離すことができる。従って、L
D50とTR51に関係する他の回路55〜57を互い
に離れた位置に設けることができる。
50 in the figure is a laser diode circuit (represented by LD),
Reference numeral 51 represents a transistor circuit (indicated by TR) of the drive section, and a connector is provided at the output terminal 53 of the TR and the input terminal 52 of the LD, and a coaxial cable 54 is connected by the connector, so that it is possible to separate the two. can. Therefore, L
Other circuits 55-57 related to D50 and TR51 can be provided at locations separated from each other.

[発明の効果〕 本発明によれば伝送線路を用いて駆動部の回路とレーザ
・ダイオードとの間を接続することにより、両者を任意
の距離で接続することができ、短かい距離内に多数の回
路を接続する必要がな(なり、実装が容易になる。
[Effects of the Invention] According to the present invention, by connecting the driver circuit and the laser diode using a transmission line, it is possible to connect the two at any distance, and a large number of laser diodes can be connected within a short distance. There is no need to connect the other circuits (this makes implementation easier.

【図面の簡単な説明】[Brief explanation of the drawing]

第1図は本発明の基本的構成図、第2図(alは本発明
の実施例1の構成図、第2図(blは本発明の実施例2
の構成図、第2図FC+は本発明の具体的な適用例の構
成図、第3図は従来例の構成図を示す。 第1図中、 10:駆動部 11:整合回路 12:伝送線路 13:レーザ・ダイオード 14:整合用抵抗 本発明の基本的構成図 菓1図 一■ 本発明の実施例1の構成図 第2図(G) ■S 本発明の実施例2の襦Ffi図 第 2 図化) 本発明の通用例の構成図 第 2 図 (0 従来例のl!構成 図3図
Figure 1 is a basic configuration diagram of the present invention, Figure 2 (al is a configuration diagram of Embodiment 1 of the present invention, and Figure 2 (bl is Embodiment 2 of the invention
FIG. 2 FC+ is a block diagram of a specific application example of the present invention, and FIG. 3 is a block diagram of a conventional example. In Figure 1, 10: Drive unit 11: Matching circuit 12: Transmission line 13: Laser diode 14: Matching resistor Basic configuration diagram of the present invention Figure 1 Figure 1 ■ Configuration diagram of Embodiment 1 of the present invention 2 Figure (G) ■S Ffi diagram of Embodiment 2 of the present invention (2nd diagram) Configuration diagram of a common example of the present invention Figure 2 (0 1! Configuration diagram of conventional example 3)

Claims (1)

【特許請求の範囲】 駆動部(10)の出力によりレーザ・ダイオード(13
)を駆動する回路において、 駆動部の出力端(100)にコンデンサと抵抗から成る
整合回路(11)を設け、 レーザ・ダイオードの入力端(130)とレーザ・ダイ
オード(13)とを直列の整合用抵抗(14)を介して
接続し、 該駆動部(10)の出力端(100)とレーザ・ダイオ
ードの入力端(130)の間を同軸ケーブル、マイクロ
ストリップライン等の特性インピーダンスを有する伝送
線路(12)により接続することを特徴とするレーザ・
ダイオード駆動回路。
[Claims] The output of the driver (10) causes the laser diode (13
), a matching circuit (11) consisting of a capacitor and a resistor is provided at the output end (100) of the drive section, and the input end (130) of the laser diode and the laser diode (13) are matched in series. A transmission line having a characteristic impedance, such as a coaxial cable or a microstrip line, is connected between the output end (100) of the drive section (10) and the input end (130) of the laser diode through a resistor (14). (12) A laser device characterized by being connected by
Diode drive circuit.
JP63039281A 1988-02-22 1988-02-22 Laser diode driving circuit Pending JPH01214081A (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
JP63039281A JPH01214081A (en) 1988-02-22 1988-02-22 Laser diode driving circuit

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
JP63039281A JPH01214081A (en) 1988-02-22 1988-02-22 Laser diode driving circuit

Publications (1)

Publication Number Publication Date
JPH01214081A true JPH01214081A (en) 1989-08-28

Family

ID=12548781

Family Applications (1)

Application Number Title Priority Date Filing Date
JP63039281A Pending JPH01214081A (en) 1988-02-22 1988-02-22 Laser diode driving circuit

Country Status (1)

Country Link
JP (1) JPH01214081A (en)

Cited By (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPH0427172A (en) * 1990-05-22 1992-01-30 Nec Corp Driving circuit for light emitting element
US5268917A (en) * 1991-08-15 1993-12-07 Northern Telecom Limited Injection laser modulation
JP2006135396A (en) * 2004-11-02 2006-05-25 Macnica Inc Circuit for driving load resistor with small dynamic resistance
JP2009289836A (en) * 2008-05-27 2009-12-10 Oki Data Corp Light emitting element array, drive control device, recording head, and image forming device

Cited By (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPH0427172A (en) * 1990-05-22 1992-01-30 Nec Corp Driving circuit for light emitting element
US5268917A (en) * 1991-08-15 1993-12-07 Northern Telecom Limited Injection laser modulation
JP2006135396A (en) * 2004-11-02 2006-05-25 Macnica Inc Circuit for driving load resistor with small dynamic resistance
JP2009289836A (en) * 2008-05-27 2009-12-10 Oki Data Corp Light emitting element array, drive control device, recording head, and image forming device
US7924304B2 (en) 2008-05-27 2011-04-12 Oki Data Corporation Light-emitting element array, drive controlling device, recording head, and image forming device

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