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1. 发明专利

JPH11275755A Light receiving circuit having avalanche photodiode protection circuit 失效
标题翻译：具有AVALANCHE光电保护电路的光接收电路
公开(公告)号：JPH11275755A
公开(公告)日：1999-10-08
申请号：JP7075098
申请日：1998-03-19
申请人： Fujitsu Ltd , 富士通株式会社
发明人： OKUMA YOSHINORI , MIYAKI YUJI
IPC分类号： H02H3/20 , H02H9/04 , H03F3/08 , H04B10/079 , H04B10/40 , H04B10/50 , H04B10/60 , H04B10/67 , H04B10/69 , H04B10/80 , H04B10/04 , H04B10/06 , H04B10/14 , H04B10/26 , H04B10/28
摘要： PROBLEM TO BE SOLVED: To prevent destruction owing to the overvoltage of a photodiode in the supply process of power voltage, by installing an avalanche photodiode for a bias control circuit, and detecting that applied voltage is overvoltage.
SOLUTION: A Zener diode D1 is connected to an avalanche photodiode APD in parallel. Namely, the cathode of the Zener diode D1 is connected to the cathode of the avalanche photodiode APD and the anode of the Zener diode D1 is connected. The Zener diode D1 which is thus connected in parallel constitutes an avalanche photodiode protection circuit PR1. Thus, current flows from a power source to ground through resistors R1 and R2 and the Zener diode D1. Since the voltage of a connection point V1 drops as a result, the destruction of the avalanche photodiode APD owing to overvoltage is prevented.
COPYRIGHT: (C)1999,JPO
摘要翻译：要解决的问题：为了防止在电源电压供给过程中由于光电二极管的过电压而造成的破坏，通过安装用于偏置控制电路的雪崩光电二极管，并且检测施加的电压是过电压。解决方案：齐纳二极管D1并联连接到雪崩光电二极管APD。也就是说，齐纳二极管D1的阴极连接到雪崩光电二极管APD的阴极，并且齐纳二极管D1的阳极被连接。并联连接的齐纳二极管D1构成雪崩光电二极管保护电路PR1。因此，电流从电源通过电阻器R1和R2以及齐纳二极管D1流到地。由于连接点V1的电压因此下降，所以防止了由过电压引起的雪崩光电二极管APD的破坏。

2. 发明专利

JPH06160238A OPTICAL VARIATION RESISTANCE TESTING EQUIPMENT 失效
公开(公告)号：JPH06160238A
公开(公告)日：1994-06-07
申请号：JP31176992
申请日：1992-11-20
申请人： FUJITSU LTD
发明人： NAGAKUBO YASUNARI , OKUMA YOSHINORI
IPC分类号： G01M11/00 , H04B10/07 , H04B10/079 , H04B10/2507 , H04B10/54 , H04B10/556 , H04B10/08
摘要： PURPOSE:To provide an optical variation resistance testing equipment for assisting measurement of optical variation resistance, representing stability at receiving terminal in terms of bit error, against variation of transmission characteristics caused by mechanical impact applied on an operating optical transmission line in which mechanical impact being applied on an optical fiber can be simulated positively and accurately. CONSTITUTION:The optical variation resistance testing equipment comprises means 11 for generating a signal corresponding to variation of transmission characteristics of an optical transmission line caused by mechanical impact applied thereon, and an indirect modulating means 13 for modulating a reference optical signal, corresponding to an optical signal put on the optical transmission line at a transmission terminal while being modulated according to transmission information, with a signal generated from the signal generating means 11 according to the transmission system for that optical transmission system thus simulating variation of optical transmission characteristics and then assisting measurement of optical variation resistance which represents stability of bit error rate at receiving terminal.

3. 发明专利

JPH02292882A OPTICAL OUTPUT CONTROL CIRCUIT 失效
公开(公告)号：JPH02292882A
公开(公告)日：1990-12-04
申请号：JP11216389
申请日：1989-05-02
申请人： FUJITSU LTD
发明人： OKUMA YOSHINORI , YAMANE KAZUO , WADA TETSUO
IPC分类号： H04B10/293 , H01S5/068 , H04B10/07 , H04B10/564 , H04B10/572
摘要： PURPOSE:To prevent output light from varying in level due to the change of a bias current caused by temperature change by a method wherein a variable offset voltage generating section which enables an offset voltage to change directly proportional to the temperature change is provided. CONSTITUTION:A variable offset voltage generating section 21 is composed of two diodes d and two potential dividing resistors R and R' (adjustable), where the characteristic inclinations of a reference voltage Vr(=Vm+Vo) at temperature of, for instance, 5 deg.C, 25 deg.C, and 55 deg.C are made different from each other. Concretely, an offset voltage Vo as one of factors which determine the reference voltage Vr is changed corresponding to the temperature change. The property of the diode d that its forward voltage drop is temperature-dependent is used for this purpose, for instance, it has a temperature characteristic of -2mV/ deg.C. A comparator 11 is a comparator formed of an operational amplifier, a bias control section 12 is composed of transistors, a pulse current control section 13 is formed of a pair of differential transistors, and a transistor Q is connected to the emitters of these transistors to serve as a common current source. The output of the comparator 11 is inputted into the base of the transistor Q through the intermediary of an amplifier A.

4. 发明专利

JPH01152654A PELTIER ELEMENT CONTROL CIRCUIT 失效
公开(公告)号：JPH01152654A
公开(公告)日：1989-06-15
申请号：JP31154287
申请日：1987-12-09
申请人： FUJITSU LTD
发明人： TSUDA TAKASHI , ONISHI MASARU , OKUMA YOSHINORI , KITASAGAMI HIROO , ARAI MASANORI , SUZUKI KAZUHIRO , WADA TETSUO
IPC分类号： H01L23/38 , H01S5/042
摘要： PURPOSE:To curtail the number of constituent elements and reduce electricity consumption, drive voltage, and manufacturing costs as well, by causing a transistor circuit that is connected to an output of a control voltage generating circuit to be connected to a Peltier element in series. CONSTITUTION:Elements 101 and 102 are Peltier elements for heating and cooling. When the operation temperature of a laser diode rises, a relevant relation is shown as follows: Setting operation temp. reduced voltage Vref> Operation temp. reduced voltage Vx. and a control voltage VB is generated out of an operational amplifier 20c. As soon as a transistor Q2 receives the above control voltage VB at its base, it is turned ON and a Peltier element drive current corresponding to its voltage value flows through the transistor Q2 and an operating temperature of a laser diode decreases. On the contrary, as soon as the operation temperature of the laser diode 2 becomes lower than that of setting operation temperature, the relevant relation is shown as follows: Setting operation temp. reduced voltage Vref

5. 发明专利

JPH01117512A AGC CONTROL SYSTEM 失效
公开(公告)号：JPH01117512A
公开(公告)日：1989-05-10
申请号：JP27633787
申请日：1987-10-30
申请人： FUJITSU LTD
发明人： TSUDA TAKASHI , ARAI MASANORI , ONISHI MASARU , KITASAGAMI HIROO , OKUMA YOSHINORI , MIYAUCHI AKIRA
IPC分类号： H03G3/30 , H03G3/20 , H04B10/079 , H04B10/293 , H04B10/564 , H04B10/572
摘要： PURPOSE:To reduce the minimum photodetection level by making the level constant when the level detected by a detection circuit is smaller than a prescribed value in the AGC control circuit, fixing the control voltage when the level is larger and varying the multiple factor of the APD so as to make the level constant thereby minimizing the inter-code interference. CONSTITUTION:A bias voltage VAPD control section 33 of the APD controls the multiple factor M of the APD so as to make a difference signal from a comparator 31 zero based on the signal from the comparator 31. A comparator 34 fixes the control voltage generated by a VAGC generating section 32 to a prescribed level when the control voltage VAGC is smaller than the control switching level VB to inhibit the gain control (E-AGC) of the variable gain amplifier. When the VAGC is larger than the VB, the VAGC generating section 32 is brought into the operating state to apply E-AGC to fix the control signal level outputted from the VAPD control section 33. Since the E-AGC by the variable gain amplifier is applied when the photodetection level is small in this way, the bend is not changed near the minimum photodetection level.

6. 发明专利

JPS6416049A OPTICAL RECEPTION EQUIPMENT ADJUSTING METHOD 失效
公开(公告)号：JPS6416049A
公开(公告)日：1989-01-19
申请号：JP17156687
申请日：1987-07-09
申请人： FUJITSU LTD
发明人： SUZUKI KAZUHIRO , MORI MASAKAZU , YAMANE KAZUO , OKUMA YOSHINORI
IPC分类号： H04B10/61 , H04B10/07 , H04B10/516 , H04B10/69 , H04L25/02 , H04L25/03
摘要： PURPOSE:To easily attain the adjustment while taking the phase fluctuation into account by adding a phase fluctuation to a clock component extracted from an electric signal so as to adjust the photoreceiver thereby minimizing the data error rate. CONSTITUTION:In case of adjusting the optical receiver including a clock component extraction section 5 and an identification section 4, a phase fluctuation addition means 7 adding a phase fluctuation is provided to the clock component. Then the output of the phase fluctuation adding means 7 is used to given adjustment so that the data error rate extracted by the section 4 by using the output of the means 7 is minimized. That is, the electric signal with phase fluctuation actually is identified by a clock without phase fluctuation and the electric signal without phase fluctuation is identified by using the clock with phase fluctuation to adjust the optical receiver under the same condition as the actual codition. Thus, the adjustment taking the phase fluctuation into account is easily executed.

7. 发明专利

JPS63204778A SEMICONDUCTOR LASER DEVICE 失效
公开(公告)号：JPS63204778A
公开(公告)日：1988-08-24
申请号：JP3583787
申请日：1987-02-20
申请人： FUJITSU LTD
发明人： MORI MASAKAZU , OKUMA YOSHINORI , SUZUKI KAZUHIRO , YAMANE KAZUO
IPC分类号： H01S5/06 , H01S3/23 , H01S5/068
摘要： PURPOSE:To suppress the amount of dispersion of an emission delay time in the case of superspeed modulation of a semiconductor laser by mounting separately a light source for injecting a direct current light consisting of a light emission diode and the like in a semiconductor emission region and by driving its light source for injecting the direct current light that is independent of a semiconductor laser, thereby using a direct current. CONSTITUTION:In addition to a semiconductor laser 11, a light source 13 for injecting a direct current light corresponding to a direct current bias emission source is mounted and a direct current light 14 out of the light source 13 is injected in an emission region 12 of the laser 11 as a seed for generating a laser beam 15 and then the direct light 14 out of the light source 13 is independently suppressed. In this way, the light source 13 is so less dependent to a temperature in comparison with the semiconductor laser's dependency to the temperature that its light source 13 is not affected by temperature changes or characteristic deterioration of the element itself and stablly controls the amount of dispersion of an emission delay time in the semiconductor laser.

8. 发明专利

JPS62217712A PULSE AMPLIFIER 失效
公开(公告)号：JPS62217712A
公开(公告)日：1987-09-25
申请号：JP5946486
申请日：1986-03-19
申请人： FUJITSU LTD
发明人： YAMANE KAZUO , MORI MASAKAZU , TSUDA TAKASHI , OKUMA YOSHINORI , SUZUKI KAZUHIRO
IPC分类号： H03K5/02 , H03G3/10
摘要： PURPOSE:To control variably the pulse amplitude without changing the pulse width by impressing negative logic input pulse to a gate electrode of a FET so as to vary a gate-source voltage in a voltage range higher than the pinch-off voltage. CONSTITUTION:In selecting the gate-source voltage impressed to the FET 3 to a voltage V(GS11) higher than the pinch-off voltage VP0, one portion of an input pulse Pi3 is cut off and the pulse amplitude of an output pulse P03 is A3 and the pulse width is W3. On the other hand, in impressing a voltage V(GS12) higher than the voltage V(GS11) to the FET 3, the amplitude A4 of an output pulse P04 and the pulse width W4 have the relation of A3 W4. In inputting an output of the FET 3 to a FET 7, the '0' level of the input pulse is arranged to a constant value V(GSC) by a clamp diode 6. Thus, the same portion of the pulses P04, P03 is cut off by the pinch off voltage VP0 of the FET, the pulse widths W31, W41 of the pulses P003, P004 are nearly equal and the pulse amplitudes are A31, A41.

9. 发明专利

JPS6294994A LASER DIODE DRIVE CIRCUIT 失效
公开(公告)号：JPS6294994A
公开(公告)日：1987-05-01
申请号：JP23463485
申请日：1985-10-22
申请人： FUJITSU LTD
发明人： YAMANE KAZUO , OKUMA YOSHINORI , MORI MASAKAZU
IPC分类号： H01S5/042 , H01S5/062 , H01S5/068 , H01S5/0683 , H03K5/02
摘要： PURPOSE:To contrive the improvement in yield by absorbing the variability included in an LD and an FET by introducing an FET for loop gain control in a light output stabilizing loop which forms an LD drive circuit, and modulating the operation characteristics by the output of an operation characteristic compensation circuit of said FET. CONSTITUTION:Adjustable resistors RV1 and RV2 commonly accept the level variation of the light output OUT sent from a light output stabilizing control part 14. Meanwhile, a resistor R2 accepts first offset voltage Vof1 and a resistor R5 accepts a second offset voltage Vof2. By presetting these offset voltages properly, the unevenness of the pinch-off voltages of an FET1 and an FET2 can be uniformed. Also, as those adjustable resistors RV1 and RV2 exist directly in a loop of a light output stabilizing loop, they modulate not only the unevenness of characteristics of the FETs, but also the comprehensive loop gain including the unevenness of threshold value or differential quantum efficiency of an LD itself.

10. 发明专利

JPH0837497A OPTICAL AMPLIFIER AND OPTICAL TRANSMITTER 失效
公开(公告)号：JPH0837497A
公开(公告)日：1996-02-06
申请号：JP2364095
申请日：1995-02-13
申请人： FUJITSU LTD
发明人： TAKAHASHI TSUKASA , ITO HIROYUKI , TAMURA YUJI , SHIMA MICHIKAZU , YAMANE KAZUO , KAWASAKI YUMIKO , OKUMA YOSHINORI , SUZUKI KAZUHIRO , MIYAKI YUJI , NAGAKUBO YASUNARI , TSUDA TAKASHI , IMAI KEISUKE
IPC分类号： H01S3/07 , H01S3/06 , H01S3/067 , H01S3/10 , H01S3/13 , H01S3/131 , H04B10/07 , H04B10/2507 , H04B10/29 , H04B10/293 , H04B10/564 , H04B10/572 , H04B10/17 , H04B10/04 , H04B10/06 , H04B10/14 , H04B10/16
摘要： PURPOSE:To prevent production of an optical surge by detecting whether or not an amplified signal light is included in an output light of a doped fiber and controlling a pump so as to decrease the intensity of a pump light when it is detected that no signal light is included. CONSTITUTION:A signal to be amplified is fed to a 1st terminal of an erbium doped fiber 2 and a 2nd terminal connects optically to a port 4A of a optical multiplexer 4. A laser diode 6 as a pump light source is optically connected to a port 4B of the optical multiplexer 4. An optical filter means 8 demultipelxes the light into an amplified signal optical output and a naturally dissipated optical output OP2. Outputs of photo detectors 14, 10 are calculated by an arithmetic means 16 and a comparator 18 compares it with a reference voltage 20. The output of the comparator 18 is used to drive a laser diode 6 via an LD controller 22. When the signal light is interrupted, the LD controller 22 controls the pump so that the intensity of the pump light is at a prescribed low level. Thus, no optical surge is produced when the input of the signal light is restored.

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