JP2710974B2 - Optical transmitter - Google Patents

Optical transmitter

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Publication number
JP2710974B2
JP2710974B2 JP1011715A JP1171589A JP2710974B2 JP 2710974 B2 JP2710974 B2 JP 2710974B2 JP 1011715 A JP1011715 A JP 1011715A JP 1171589 A JP1171589 A JP 1171589A JP 2710974 B2 JP2710974 B2 JP 2710974B2
Authority
JP
Japan
Prior art keywords
current
emitting element
light emitting
light
binary
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 - Fee Related
Application number
JP1011715A
Other languages
Japanese (ja)
Other versions
JPH02192332A (en
Inventor
邦明 本島
実百紀 周治
忠義 北山
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.)
Mitsubishi Electric Corp
Original Assignee
Mitsubishi Electric Corp
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 Mitsubishi Electric Corp filed Critical Mitsubishi Electric Corp
Priority to JP1011715A priority Critical patent/JP2710974B2/en
Priority to IT67033A priority patent/IT1239537B/en
Priority to DE19904001898 priority patent/DE4001898C2/en
Priority to DE19904042407 priority patent/DE4042407C2/en
Priority to US07/469,077 priority patent/US5107362A/en
Publication of JPH02192332A publication Critical patent/JPH02192332A/en
Application granted granted Critical
Publication of JP2710974B2 publication Critical patent/JP2710974B2/en
Anticipated expiration legal-status Critical
Expired - Fee Related legal-status Critical Current

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  • Semiconductor Lasers (AREA)

Description

【発明の詳細な説明】 〔産業上の利用分野〕 この発明は、発光素子としてレーザダイオード(以下
LDと略す)を用いた光送信装置の動作温度範囲を拡大す
ることのできる光送信装置に関する。
DETAILED DESCRIPTION OF THE INVENTION [Industrial Application Field] The present invention relates to a laser diode (hereinafter, referred to as a light emitting element).
The present invention relates to an optical transmission device capable of expanding an operating temperature range of an optical transmission device using LD (abbreviated as LD).

〔従来の技術〕[Conventional technology]

第4図は、例えば昭和58年度電子通信学会総合全国大
会2246「キャリア検出回路付100Mb/sレーザダイオード
光送信器」に示された従来の光送信装置を示す回路構成
図であり、同図において(1)は送信データを入力する
送信データ入力端子、(2)は該送信データ入力端子
(1)にて入力された送信データに基づき2値化電流を
変調制御する変調器、(3)は該変調器(2)の2値化
電流に基づいて発光する発光素子としてのレーザダイオ
ード(以下LD)、(4)は該LD(3)の出力光の一部を
受光して光電変換する受光素子、(5)は該受光素子
(4)が受光した出力光の基準値となる基準電流を出力
する基準電流源、(6)は該基準電流源(5)の基準電
流と受光素子(4)にて変換された信号電流との差電流
に比例した駆動電流を供給する電流増幅器、(7)は上
記受光素子(4)のバイアス電源、(8)は上記受光素
子(4)に並列接続されたコンデンサである。
FIG. 4 is a circuit configuration diagram showing a conventional optical transmission device shown in, for example, the 1979 IEEJ General Conference 2246 "100Mb / s Laser Diode Optical Transmitter with Carrier Detection Circuit". (1) is a transmission data input terminal for inputting transmission data, (2) is a modulator that modulates and controls a binary current based on the transmission data input at the transmission data input terminal (1), and (3) is a modulator. A laser diode (hereinafter referred to as an LD) as a light emitting element that emits light based on the binarized current of the modulator (2), and a light receiving element (4) that receives a part of the output light of the LD (3) and performs photoelectric conversion An element, (5) a reference current source for outputting a reference current serving as a reference value of the output light received by the light receiving element (4), and (6) a reference current of the reference current source (5) and the light receiving element (4). ) To supply a drive current proportional to the difference current from the signal current converted Flow amplifier, a bias power supply, capacitor connected in parallel to (8) above the light receiving element (4) in (7) above the light receiving element (4).

第5図はLDの駆動電流対光出力特性を示す出力特性図
であり、同図において、(13)は低温におけるP−I特
性、(14)は高温におけるP−I特性である。
FIG. 5 is an output characteristic diagram showing a drive current versus optical output characteristic of the LD. In FIG. 5, (13) shows a PI characteristic at a low temperature, and (14) shows a PI characteristic at a high temperature.

第6図は、電流増幅器(6)の構成例を示す図であ
り、(15)〜(17)はこの構成要素となるトランジスタ
である。
FIG. 6 is a diagram showing an example of the configuration of a current amplifier (6), wherein (15) to (17) denote transistors serving as this component.

次に上記従来の光送信装置の動作について説明する。
送信データ入力端子(1)に入力された送信データは、
変調器(2)に入力される。この変調器(2)は送信デ
ータに対応した電流を発生し、LD(3)に印加する。ま
た、送信データは基準電流源(5)に入力され、送信デ
ータのマーク率に比例した電流と一定電流の和電流を基
準電流I0として、電流増幅器(6)へ出力する。受光素
子(4)にはLD(3)の光出力の一部が入力されること
により受光素子電流IPDが流れ、電流増幅器(6)へ入
力される。電流増幅器(6)には基準電流I0と受光素子
電流IPDの差電流が入力され、一定倍率βだけ増幅され
た後LD(3)にバイアス電流として供給される。従っ
て、LD(3)の光出力が大きくなると、受光素子(4)
に流れる電流が大きくなり、電流増幅器(6)の出力電
流が小さくなってLD(3)の光出力は低下する。LD
(3)の光出力が低下した場合は、上記と逆の理由によ
りLD(3)の光出力は増加する。以上の負帰還動作によ
りLD(3)の光出力は一定値に保たれる。
Next, the operation of the conventional optical transmission device will be described.
The transmission data input to the transmission data input terminal (1)
The signal is input to the modulator (2). The modulator (2) generates a current corresponding to the transmission data and applies it to the LD (3). The transmission data is input to the reference current source (5), as the reference current I 0 the sum current of the constant current and current proportional to the mark ratio of the transmission data, and outputs it to the current amplifier (6). When a part of the optical output of the LD (3) is input to the light receiving element (4), the light receiving element current IPD flows and is input to the current amplifier (6). The difference current between the reference current I 0 and the light-receiving element current I PD is input to the current amplifier (6), and after being amplified by a constant magnification β, supplied to the LD (3) as a bias current. Therefore, when the light output of the LD (3) increases, the light receiving element (4)
The current flowing through the LD (3) increases, the output current of the current amplifier (6) decreases, and the optical output of the LD (3) decreases. LD
When the light output of (3) decreases, the light output of LD (3) increases for the opposite reason. By the above negative feedback operation, the light output of the LD (3) is kept at a constant value.

ディジタル信号を伝送する際の光信号のピーク値に着
目すると、LD(3)の光出力のピーク値Poutは次のよう
に表わされる。
Focusing on the peak value of the optical signal when transmitting the digital signal, the peak value P out of the optical output of the LD (3) is expressed as follows.

Pout=A(IB+IOP−Ith) (1) 但し、IB=β(IO−IPD) (2) IPD=mDLPout (3) IB:バイアス電流(電流増幅器出力電流) IOP:変調電流(変調器出力電流) Ith:LD閾値電流 β:電流増幅器増幅率 IPD:受光素子電流 IO:基準電流 m:ディジタル信号のマーク率(0<m≦1) L:光出力と受光素子電流変換率 A:LD電流・光変換効率 D:パルス占有率 第(1)式、第(2)式、第(3)式より、 となる。第(4)式において、マーク率mが変化しても
光出力Poutが一定であるためには、マーク率に応じて基
準電流IOを制御する必要がある。そこで、Pout=K(一
定)とおくと、 IO=IO1+mIO2 但し、 となる。基準電流源(5)は第(5)式に示したよう
に、一定電流IO1とマーク率に比例した電流mIO2の和電
流IOを電流増幅器(6)に供給し、LD(3)の光出力は
マーク率によらず一定となる。
P out = A (I B + I OP −I th ) (1) where I B = β (I O −I PD ) (2) I PD = mDLP out (3) I B : Bias current (current amplifier output current) ) I OP : Modulation current (modulator output current) I th : LD threshold current β: Current amplifier amplification factor I PD : Photodetector current I O : Reference current m: Mark ratio of digital signal (0 <m ≦ 1) L : Light output and light-receiving element current conversion ratio A: LD current / light conversion efficiency D: Pulse occupancy ratio From the formulas (1), (2), and (3), Becomes In the formula (4), it is necessary to control the reference current IO in accordance with the mark rate so that the light output P out is constant even if the mark rate m changes. Therefore, if P out = K (constant), I O = I O1 + mI O2 where Becomes Reference current source (5) the first (5) as indicated formula, and supplies the sum current I O the current amplifier of a current mI O2 proportional constant current I O1 and mark ratio (6), LD (3) Is constant regardless of the mark ratio.

次に温度が変動した場合の光送信装置の動作について
考える。第5図はLDの駆動電流対光出力特性を示す図で
ある。温度に対して変動するパラメータをLD閾値電流I
thのみとすると、第(4)式より 第(6)式において、1.3μm帯ファブリ・ペロー型L
Dでの値を考えると、 A=0.11〔W/A〕 L=0.14〔A/W〕 程度の値となる。温度範囲を−30℃〜+85℃、T=25
℃での光出力1mwの場合を考える。各マーク率で光出力1
dB以下とするには、第(6)式より (7)式よりβ≧17737となる。但しマーク率の最小値
は1/8とした。
Next, the operation of the optical transmitter when the temperature fluctuates will be considered. FIG. 5 is a diagram showing a drive current versus light output characteristic of an LD. LD threshold current I
If only th is given, from equation (4) In equation (6), the Fabry-Perot type L at 1.3 μm band
Considering the value at D, A = 0.11 [W / A] L = 0.14 [A / W] Value of the order. Temperature range from -30 ° C to + 85 ° C, T = 25
Consider a case where the light output at 1 ° C. is 1 mw. Light output 1 at each mark rate
In order to make it less than dB, from equation (6) From equation (7), β ≧ 17737 holds. However, the minimum value of the mark ratio was 1/8.

上述のように、電流増幅器(8)の電流増幅率βとし
ては非常に大きい値が要求され、第6図に示すようなダ
ーリントン型の回路が用いられる。トランジスタ(15)
〜(17)の電流増幅率をそれれβ、β、βとする
と、電流増幅器増幅率βは β=β・β・β (8) となる。一般にnpnトランジスタの電流増幅率は30以上
が得られるので、第6図に示した電流増幅器でβは2700
0以上の値が得られる。従ってトランジスタ(14)〜(1
6)が導通状態にあれば、第6図に示した電流増幅器は
充分大きい電流増幅率を持ち、良好なAPC(Automatic P
ower Control)特性が得られる。
As described above, a very large value is required for the current amplification factor β of the current amplifier (8), and a Darlington type circuit as shown in FIG. 6 is used. Transistor (15)
~ It Re beta 1 a current amplification factor of the (17), β 2, when the beta 3, a current amplifier gain beta becomes β = β 1 · β 2 · β 3 (8). Generally, the current amplification factor of the npn transistor is 30 or more, so that β is 2700 in the current amplifier shown in FIG.
A value of 0 or more is obtained. Therefore, transistors (14) to (1
If 6) is in the conducting state, the current amplifier shown in FIG. 6 has a sufficiently large current amplification factor and a good APC (Automatic P
(ower Control) characteristics.

〔発明が解決しようとする課題〕[Problems to be solved by the invention]

従来の光送信装置は以上のように構成されていたの
で、一般にLD(3)のバイアス電流が閾値電流以下に設
定され、第5図において高温時にはバイアス電流IB1
充分大きくしても、低温時にはバイアス電流IB2がほぼ
0となる場合がある。この場合、第6図に示した電流増
幅器トランジスタ(15)〜(17)は遮断状態となり、電
流増幅率は非常に小さくなり、マーク率、温度変動に対
して光出力のピーク値を一定値に保つのに要求される電
流増幅率を確保できなくなり、この電流増幅率の低下に
よりAPC特性が劣化するという課題があった。
Because I the conventional optical transmission apparatus configured as described above, generally set below the bias current is the threshold current of the LD (3), it is sufficiently large bias current I B1 is at a high temperature in the Figure 5, the low temperature sometimes it may become bias current I B2 substantially zero. In this case, the current amplifier transistors (15) to (17) shown in FIG. 6 are turned off, the current amplification rate becomes very small, and the peak value of the optical output becomes constant with respect to the mark rate and temperature fluctuation. The current amplification factor required to maintain the current amplification factor cannot be secured, and there is a problem that the APC characteristic is deteriorated due to the decrease in the current amplification factor.

この第1の発明は上記のような課題を解消するために
なされたもので、LD(3)P−I特性及び温度変動に依
存しないAPC特性の良好な光送信装置を得ることを目的
とする。
The first invention has been made to solve the above-described problems, and has as its object to obtain an optical transmitter having good LD (3) P-I characteristics and APC characteristics independent of temperature fluctuation. .

また、この第2の発明はAPC特性を良好にすると共
に、消光比、光出力ピーク値を一定に保つことのできる
光送信装置を得ることを目的とする。
Another object of the second invention is to provide an optical transmitter capable of improving the APC characteristic and keeping the extinction ratio and the optical output peak value constant.

〔課題を解決するための手段〕[Means for solving the problem]

この第1の発明に係る光送信装置は、2値化送信デー
タに基づき電流変調手段にて2値化電流を発光素子に供
給し、該発光素子の一部を光電変換手段にて受光して変
換し、該光電変換された信号電流と基準電流との差電流
に比例した駆動電流を電流増幅手段にて発光素子に供給
し、該駆動電流を発光素子に並列接続された抵抗素子に
て一定値以上に維持するものである。
The optical transmitter according to the first invention supplies a binary current to the light emitting element by the current modulation means based on the binary transmission data, and receives a part of the light emitting element by the photoelectric conversion means. The driving current, which is proportional to the difference current between the converted and photoelectrically converted signal current and the reference current, is supplied to the light emitting element by the current amplifying means, and the driving current is fixed by the resistance element connected in parallel to the light emitting element. Should be kept above the value.

この第2の発明に係る光送信装置は、2値化送信デー
タに基づき電流変調手段にて2値化電流を発光素子に供
給し、該電流変調手段の2値化電流を高温下で大きく
し、低温下で小さくする補償を変調電流温度補償手段に
て制御し、上記発光素子の一部を光電変換手段にて受光
して光電変換し、該光電変換された信号電流と基準電流
との差電流に比例した駆動電流を電流増幅手段にて発光
素子に供給し、該駆動電流を発光素子に並列接続された
抵抗素子にて一定値以上に維持するものである。
The optical transmitter according to the second aspect of the present invention supplies a binary current to the light emitting element by the current modulator based on the binary transmission data, and increases the binary current of the current modulator at a high temperature. The modulation current temperature compensating means controls the compensation for reducing the temperature at a low temperature, a part of the light emitting element is received by the photoelectric converting means, photoelectrically converted, and the difference between the photoelectrically converted signal current and the reference current. A drive current proportional to the current is supplied to the light emitting element by current amplification means, and the drive current is maintained at a certain value or more by a resistance element connected in parallel to the light emitting element.

〔作用〕[Action]

この第1の発明における光送信装置は、発光素子に並
列接続された抵抗素子にて、電流増幅手段の駆動電流を
いかなる温度下においても充分大きくすることができ、
APC特性を良好なものとする。
In the optical transmission device according to the first aspect, the driving current of the current amplifying means can be sufficiently increased at any temperature by the resistance element connected in parallel to the light emitting element,
APC characteristics are improved.

また第2の発明における光送信装置は、上記第1の発
明と同様にAPC特性を良好なものとすることができ、さ
らに変調電流温度補償手段の補償制御により電流変調手
段の2値化電流を補償して発光素子のバイアス点を一定
にできることとなり、消光比・光出力ピーク値を一定に
保持できることとなる。
Further, the optical transmitter according to the second invention can improve the APC characteristic similarly to the first invention, and further reduces the binarized current of the current modulation means by the compensation control of the modulation current temperature compensation means. By compensating, the bias point of the light emitting element can be kept constant, and the extinction ratio / light output peak value can be kept constant.

〔実施例〕〔Example〕

以下、この第1の発明の一実施例を第1図に基づいて
説明する。この第1図は本実施例装置の構成回路図を示
し、同図において本実施例に係る光送信装置は、2値化
送信データを入力する送信データ入力端子(1)と、2
値化送信データに対応して2値化電流を発光素子(3)
に供給する変調器(2)と、上記発光素子(3)の出力
光の一部を受光して光電変換する受光素子(4)と、該
受光素子(4)にて変換された信号電流と基準電流源
(5)から出力される予め設定された基準電流との差電
流に比例したバイアス電流を上記発光素子(4)に供給
する電流増幅器(6)と、上記発光素子(4)に並列接
続した抵抗(9)とを備える構成である。
An embodiment of the first invention will be described below with reference to FIG. FIG. 1 is a configuration circuit diagram of the apparatus of the present embodiment, in which an optical transmitter according to the present embodiment includes a transmission data input terminal (1) for inputting binarized transmission data,
A light emitting element (3) that outputs a binarized current corresponding to the binarized transmission data
(2), a light-receiving element (4) for receiving part of the output light of the light-emitting element (3) and performing photoelectric conversion, and a signal current converted by the light-receiving element (4). A current amplifier (6) for supplying a bias current proportional to a difference current from a preset reference current output from the reference current source (5) to the light emitting element (4); And a connected resistor (9).

次に、上記構成に基づく本実施例の動作について説明
する。一般にLD(3)の順方向電圧VFは1.2(V)程度
である。従って抵抗(9)の抵抗値をRBとすると、抵抗
(9)を介して電流増幅器(6)へ流れ込む電流I′
は、 I′1.2/RB (9) と表わせる。RB=300(Ω)とするとI′=4mAとな
る。電流増幅器(6)は最悪でも4mA以上の電流が流れ
ることになり決して遮断状態にならず、高い電流増幅率
βが確保できる。抵抗(9)の値としては、LD(3)の
ON時の抵抗RONに比して充分大きい値が望ましい。RON
一般に5(Ω)程度であり、RBとして100(Ω)以上の
値であれば変調器(2)から出力される変調電流はほと
んどLD(3)に流れ、変調効率の低下は無視できる。
Next, the operation of this embodiment based on the above configuration will be described. The forward voltage V F of the generally LD (3) is about 1.2 (V). Therefore, assuming that the resistance value of the resistor (9) is R B , the current I ′ B flowing into the current amplifier (6) via the resistor (9)
Can be expressed as I ′ B 1.2 / R B (9). If R B = 300 (Ω), I ′ B = 4 mA. At the worst, a current of 4 mA or more flows through the current amplifier (6), so that the current amplifier (6) never enters a cutoff state, and a high current amplification factor β can be secured. The value of the resistor (9) is
It is desirable that the value be sufficiently larger than the resistance R ON at the time of ON . R ON is generally about 5 (Ω). If R B is a value of 100 (Ω) or more, most of the modulation current output from the modulator (2) flows to the LD (3), and the modulation efficiency decreases. I can ignore it.

この第2の発明の一実施例を第2図、第3図に基づい
て説明する。この第2図は本実施例の構成回路図、第3
図は第2図記載の回路におけるLD動作原理の駆動電流対
光出力特性図を示す。上記各図において本実施例に係る
光送信装置は、前記第1の発明の一実施例の構成に、変
調器(2)の出力電流を高温下で大きくし、低温下で小
さくする補償を制御する変調電流温度補償回路を追加す
る構成である。
An embodiment of the second invention will be described with reference to FIGS. FIG. 2 is a circuit diagram showing the configuration of this embodiment, and FIG.
The figure shows a drive current vs. light output characteristic diagram of the LD operation principle in the circuit shown in FIG. In each of the drawings, the optical transmission apparatus according to the present embodiment is different from the configuration of the first embodiment in that compensation for increasing the output current of the modulator (2) at a high temperature and decreasing it at a low temperature is controlled. This is a configuration in which a modulation current temperature compensation circuit is added.

次に、上記構成に基づく第2の発明の一実施例の動作
を説明する。第3図に示すように、LD(3)の電流・光
変換効率は温度特性を有し、1.3μm帯ファブリ・ペロ
ー型LDでは、0〜70℃で0.05W/A程度変化する。変調電
流温度補償回路(10)は、LD(3)の電流・光変換効率
に応じて低温では変調電流を小さくし、高温では変調電
流を大きくする。第3図において、変調電流、バイアス
電流はそれぞれ、以下に示す表−1の通りである。
Next, the operation of the embodiment of the second invention based on the above configuration will be described. As shown in FIG. 3, the current / light conversion efficiency of the LD (3) has a temperature characteristic, and in a 1.3 μm band Fabry-Perot LD, it changes by about 0.05 W / A at 0 to 70 ° C. The modulation current temperature compensation circuit (10) decreases the modulation current at low temperatures and increases the modulation current at high temperatures according to the current-light conversion efficiency of the LD (3). In FIG. 3, the modulation current and the bias current are as shown in Table 1 below.

この変調電流温度補償回路(12)により、LD(3)の
バイアス点を温度によらず、ほぼ一定にでき、消光比、
光出力のピーク値を一定に保つことができる。
With this modulation current temperature compensation circuit (12), the bias point of the LD (3) can be made almost constant regardless of the temperature, and the extinction ratio,
The peak value of the light output can be kept constant.

また、抵抗(9)として、温度係数が正で大きな値を
有する抵抗を用いれば、高温時における消費電力の増加
を極力小さくすることができる。現在、抵抗の温度係数
としては5000PPm/℃程度のものが利用可能である。従っ
て、−30℃〜70℃の温度範囲を考えると、抵抗値は70℃
において30℃の1.5倍となり、抵抗(9)の消費電力は6
7%に低減できる。
Further, if a resistor having a positive temperature coefficient and a large value is used as the resistor (9), an increase in power consumption at a high temperature can be minimized. At present, a resistance temperature coefficient of about 5000 PPm / ° C is available. Therefore, considering the temperature range of −30 ° C. to 70 ° C., the resistance value is 70 ° C.
Is 1.5 times of 30 ° C, and the power consumption of resistor (9) is 6
Can be reduced to 7%.

〔発明の効果〕〔The invention's effect〕

以上のようにこの第1の発明によれば発光素子に並列
に抵抗素子を接続することにより、電流増幅手段の電流
増幅率を各温度で充分高い値にでき、良好なAPC動作を
確保できるという効果を奏する。
As described above, according to the first aspect of the invention, by connecting the resistance element in parallel with the light emitting element, the current amplification factor of the current amplification means can be set to a sufficiently high value at each temperature, and a good APC operation can be secured. It works.

またこの第2の発明によれば発光素子に供給する2値
化電流を供給する電流変調手段を補償制御する変調電流
温度補償手段を付加することにより、発光素子のバイア
ス点を一定にでき、消光比、光出力ピーク値を一定に保
つことができるという効果を奏する。
According to the second aspect of the invention, the bias point of the light emitting element can be made constant by adding the modulation current temperature compensating means for compensating and controlling the current modulating means for supplying the binarized current supplied to the light emitting element. The ratio and the light output peak value can be kept constant.

【図面の簡単な説明】[Brief description of the drawings]

第1図はこの第1の発明の一実施例に係る光送信装置の
構成回路図、第2図はこの第2の発明の一実施例に係る
光送信装置の構成回路図、第3図は第2図に示した光送
信装置の動作原理の駆動電流対光出力特性図、第4図は
従来の光送信装置の構成回路図、第5図は従来の光送信
装置におけるLDの駆動電流対光出力特性図、第6図は電
流増幅器の構成例を示す図である。 図中、(1)は送信データ入力端子、(2)は変調器、
(3)はレーザダイオード(LD)、(4)は受光素子、
(5)は基準電流源、(6)は電流増幅器、(7)は発
光素子(4)のバイアス電源、(8)はコンデンサ、
(9)は抵抗、(10)は変調電流温度補償回路である。 なお、各図中同一符号は同一または相当部分を示す。
FIG. 1 is a circuit diagram of an optical transmitter according to an embodiment of the first invention, FIG. 2 is a circuit diagram of an optical transmitter according to an embodiment of the second invention, and FIG. FIG. 2 is a driving current versus optical output characteristic diagram of the operating principle of the optical transmitter shown in FIG. 2, FIG. 4 is a circuit diagram of a conventional optical transmitter, and FIG. FIG. 6 is a diagram showing a configuration example of a current amplifier. In the figure, (1) is a transmission data input terminal, (2) is a modulator,
(3) is a laser diode (LD), (4) is a light receiving element,
(5) is a reference current source, (6) is a current amplifier, (7) is a bias power supply for the light emitting element (4), (8) is a capacitor,
(9) is a resistor, and (10) is a modulation current temperature compensation circuit. In the drawings, the same reference numerals indicate the same or corresponding parts.

───────────────────────────────────────────────────── フロントページの続き (56)参考文献 特開 昭61−167231(JP,A) 特開 昭58−18988(JP,A) 特開 昭63−48885(JP,A) ────────────────────────────────────────────────── ─── Continuation of the front page (56) References JP-A-61-167231 (JP, A) JP-A-58-18988 (JP, A) JP-A-63-48885 (JP, A)

Claims (2)

(57)【特許請求の範囲】(57) [Claims] 【請求項1】2値化送信データに対応して2値化電流を
発光素子に供給する電流変調手段と、上記発光素子の出
力光の一部を受光して光電変換する光電変換手段と、該
光電変換手段にて変換された信号電流と予め設定された
基準電流との差電流に比例した駆動電流を上記発光素子
に供給する電流増幅手段と、上記発光素子に並列接続し
た抵抗素子とを備えることを特徴とする光送信装置。
1. A current modulation means for supplying a binary current to a light emitting element corresponding to binary transmission data, a photoelectric conversion means for receiving a part of output light of the light emitting element and photoelectrically converting the light, Current amplification means for supplying a drive current proportional to a difference current between the signal current converted by the photoelectric conversion means and a preset reference current to the light emitting element, and a resistance element connected in parallel to the light emitting element. An optical transmission device, comprising:
【請求項2】2値化送信データに対応して2値化電流を
発光素子に供給する電流変調手段と、該電流変調手段の
2値化電流を高温下で大きくし、低温下で小さくする補
償を制御する変調電流温度補償手段と、上記発光素子の
出力光の一部を受光して光電変換する光電変換手段と、
該光電変換手段にて変換された信号電流と予め設定され
た基準電流との差電流に比例した駆動電流を上記発光素
子に供給する電流増幅手段と、上記発光素子に並列接続
した抵抗素子とを備えることを特徴とする光送信装置。
2. A current modulation means for supplying a binary current to a light emitting element corresponding to binary transmission data, and a binary current of the current modulation means is increased at a high temperature and reduced at a low temperature. Modulation current temperature compensation means for controlling compensation, photoelectric conversion means for receiving a part of the output light of the light emitting element and performing photoelectric conversion,
Current amplification means for supplying a drive current proportional to a difference current between the signal current converted by the photoelectric conversion means and a preset reference current to the light emitting element, and a resistance element connected in parallel to the light emitting element. An optical transmission device, comprising:
JP1011715A 1989-01-20 1989-01-20 Optical transmitter Expired - Fee Related JP2710974B2 (en)

Priority Applications (5)

Application Number Priority Date Filing Date Title
JP1011715A JP2710974B2 (en) 1989-01-20 1989-01-20 Optical transmitter
IT67033A IT1239537B (en) 1989-01-20 1990-01-19 OPTICAL TRANSMISSION EQUIPMENT.
DE19904001898 DE4001898C2 (en) 1989-01-20 1990-01-19 Optical transmission device
DE19904042407 DE4042407C2 (en) 1989-01-20 1990-01-19 Optical data transmitter with temp.-independent power control
US07/469,077 US5107362A (en) 1989-01-20 1990-01-19 Optical transmission apparatus

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
JP1011715A JP2710974B2 (en) 1989-01-20 1989-01-20 Optical transmitter

Publications (2)

Publication Number Publication Date
JPH02192332A JPH02192332A (en) 1990-07-30
JP2710974B2 true JP2710974B2 (en) 1998-02-10

Family

ID=11785739

Family Applications (1)

Application Number Title Priority Date Filing Date
JP1011715A Expired - Fee Related JP2710974B2 (en) 1989-01-20 1989-01-20 Optical transmitter

Country Status (1)

Country Link
JP (1) JP2710974B2 (en)

Families Citing this family (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US5309269A (en) * 1991-04-04 1994-05-03 Mitsubishi Denki Kabushiki Kaisha Light transmitter

Also Published As

Publication number Publication date
JPH02192332A (en) 1990-07-30

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