CN1487349A - Optical amplifier, gain control method and circuit of optical amplifier - Google Patents

Optical amplifier, gain control method and circuit of optical amplifier Download PDF

Info

Publication number
CN1487349A
CN1487349A CNA031549926A CN03154992A CN1487349A CN 1487349 A CN1487349 A CN 1487349A CN A031549926 A CNA031549926 A CN A031549926A CN 03154992 A CN03154992 A CN 03154992A CN 1487349 A CN1487349 A CN 1487349A
Authority
CN
China
Prior art keywords
gain control
optical amplifier
photodetector
voltage
output
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
Application number
CNA031549926A
Other languages
Chinese (zh)
Other versions
CN1318909C (en
Inventor
中路晴雄
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.)
Sumitomo Electric Industries Ltd
Original Assignee
Sumitomo Electric Industries 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
Priority claimed from JP2002255000A external-priority patent/JP4126994B2/en
Application filed by Sumitomo Electric Industries Ltd filed Critical Sumitomo Electric Industries Ltd
Publication of CN1487349A publication Critical patent/CN1487349A/en
Application granted granted Critical
Publication of CN1318909C publication Critical patent/CN1318909C/en
Anticipated expiration legal-status Critical
Expired - Fee Related legal-status Critical Current

Links

Images

Landscapes

  • Optical Communication System (AREA)
  • Amplifiers (AREA)

Abstract

本发明涉及光放大器、光放大器的增益控制方法及电路。该光放大器能在宽动态范围内以简单结构实现高速增益控制其增益控制电路包括输出与要输入该光放大器介质的部分信号光的功率呈线性关系的电压的第一光电探测器和输出与该光放大器介质所放大的部分信号光的功率呈线性关系的电压的第二光电探测器，输出第一和第二光电探测器分别输出的电压之差的比较器，及响应比较器的输出电压，向泵浦光源提供所需驱动电流的驱动电路。第一和第二光电探测器的每一个都有响应输入光功率，将其转换为电流的光电转换元件，及将光电转换元件的输出电流转换为电压的运算放大器。尤其是，第一和第二光电探测器的至少一个具有调整输出电压的偏移的调整机制。

The invention relates to an optical amplifier, a gain control method and a circuit of the optical amplifier. This optical amplifier can realize high-speed gain control with a simple structure in a wide dynamic range. a second photodetector with a voltage in which the power of part of the signal light amplified by the optical amplifier medium is in a linear relationship, a comparator that outputs the difference between the voltages output by the first and second photodetectors respectively, and an output voltage that responds to the comparator, The drive circuit that provides the required drive current to the pump light source. Each of the first and second photodetectors has a photoelectric conversion element that converts the input optical power into a current in response to it, and an operational amplifier that converts the output current of the photoelectric conversion element into a voltage. In particular, at least one of the first and second photodetectors has an adjustment mechanism for adjusting the offset of the output voltage.

Description

Image intensifer, the gain control method of image intensifer and circuit
Technical field
The present invention relates to a kind of image intensifer, a kind of gain control method of this kind image intensifer and a kind of gain control circuit of this kind image intensifer that can amplify flashlight (WDM flashlight) with the mutually different a plurality of channels of wavelength.
Background technology
In order to satisfy the needs that message capacity is increased, the application development in recent years of wavelength division multiplex (WDM) communication system is rapid.Simultaneously, for reliability and the efficient that improves network, optical add-drop multiplexer (OADM), optical crossover connector (OXC) that is used for telling or be inserted in the part WDM flashlight of transmission over networks etc. is being introduced in the WDM communication system.
The variation of channel quantity in the necessary flexible adaptation network of WDM communication system.Correspondingly,, as be widely used in the Erbium-Doped Fiber Amplifier (EDFA) of WDM communication system as network structure, the adaptability that channel quantity changes in pair network also will be arranged at image intensifer.And, along with the widespread use of above-mentioned WDM communication system, provide the image intensifer of low price of crucial importance to market.
Yet as a kind of method of controlling gain amplifier, traditional image intensifer adopts usually and uses a kind of logarithmic amplifier to come the method for calculated gains, as publication number be the Japanese unexamined patent of 2000-40847 disclosed.Particularly, use the automatic gain control (AGC) of logarithmic amplifier calculated gains to carry out according to following principle.
Particularly, the gain of following formula (1) expression image intensifer:
G(dB)＝P OUT(dBm)-P IN(dBm) (1)
Here, G represent the gain (unit: dB), P INThe logarithm value of expression input optical power (unit: dBm), P OUTLogarithm value (the unit: dBm) of expression Output optical power.
Input side at image intensifer, the proportional voltage of luminous power of one of input side photodetector output and amplification forward part light signal, the input side logarithmic amplifier carries out log-transformation (that is output voltage V of input side logarithmic amplifier, to the voltage of input side photodetector output 1The logarithm value of the luminous power that is detected with the input side photodetector is proportional).In contrast, one of outgoing side photodetector output and the proportional voltage of amplification rear section light signal luminous power, and the outgoing side logarithmic amplifier also carries out log-transformation (that is output voltage V of outgoing side logarithmic amplifier, to the output voltage of outgoing side photodetector 2, the logarithm value of the luminous power that is detected with the outgoing side photodetector is mutually proportional).Then, by with a difference calculator with the voltage V that is obtained 1And V 2Thereby subtract each other the gain that detects image intensifer.With a comparer gain and the target gain that is detected compared, by for example adjusting pumping light power the gain of image intensifer is controlled, so that gain that is detected and target gain are each other about equally.
Simultaneously, in the example that image intensifer is carried out automatic electric-level control (ALC), the gain of image intensifer is surveyed according to said method and is obtained, and Output optical power calculates by following formula (2):
P OUT(dBm)＝G(dB)+P IN(dBm) (2)
Then, thus obtained Output optical power and target Output optical power are compared, pumping light power or other luminous powers are controlled, so that above-mentioned performance number is equal to each other.
Summary of the invention
By studying above-mentioned prior art, the present inventor has found following problems.
In the gain control of traditional image intensifer, the output voltage of photodetector carries out log-transformation by logarithmic amplifier, and gain is surveyed by using very feasible difference calculator to carry out.Yet in electronic devices and components, logarithmic amplifier is relatively costly.And the nonlinear Control circuit that contains the control circuit formation of logarithmic amplifier is difficult to design.For example, when using logarithmic amplifier, the gain of control circuit is owing to the input optical power of being surveyed may fluctuate (that is, the gain of control circuit increases along with the minimizing of the luminous power that is input to photodetector).Correspondingly, under this kind situation, if quicken, it is very unstable that control circuit may become, and reaches high speed gain control in the very wide dynamic range so be difficult in.
The invention solves foregoing problems.One of purpose of the present invention provides a kind of image intensifer that can reach the structure simpler (cost is lower) of high speed gain control in a wideer dynamic range, the gain control method of this kind image intensifer, and a kind of gain control circuit that can be used for this kind image intensifer.
Image intensifer of the present invention comprises an image intensifer medium, a pump light source, an input side coupling mechanism (first coupling mechanism) and an outgoing side coupling mechanism (second coupling mechanism) and a gain control circuit that the image intensifer medium is clipped in the middle.The image intensifer medium comprises, for example, and Er-doped fiber (EDF).Pump light source provides the pump light of predetermined wavelength to the image intensifer medium.The input side coupling mechanism comprises the tributary port (branch port) of the part of a light signal that is used to separate input image intensifer medium.The outgoing side coupling mechanism comprises a tributary port that is used for being separated in the part of the light signal that the image intensifer medium amplifies.And gain control circuit is controlled the gain of image intensifer by the difference information between the performance number of using the light of being separated by input side coupling mechanism and outgoing side coupling mechanism.Here, the gain control that gain control circuit carried out comprises automatic gain control at least.
Gain control circuit comprises an input side photodetector (first photodetector), an outgoing side photodetector (second photodetector), a comparer (being included in the control system) and a driving circuit.The voltage that the power of the light that one of input side photodetector output and input side coupling mechanism are separated has linear relationship.The voltage that the power of the light that one of outgoing side photodetector output and outgoing side coupling mechanism are separated has linear relationship.The voltage difference of the magnitude of voltage that one of comparer output obtains from input side photodetector and outgoing side photodetector respectively.And the output voltage of driving circuit response comparator to pump light source, provides desired drive current as laser diode.
Especially, for image intensifer being carried out gain control, the input optical power P of at least one in defining about input side photodetector and outgoing side photodetector iWith output voltage V oBetween the function (V of linear relationship o=aP i+ b) in, gain control circuit is adjusted slope a and intercept b.At this,, be preferably in the luminous power of the noise light (mainly being ASE light) that is contained in the consideration image intensifer output light when adjusting slope and intercept in order only the wdm optical signal that will amplify to be carried out gain control.And, change for fear of dynamic gain, preferably the response time in the gain control circuit was made as one second or shorter.
Except said structure, image intensifer of the present invention preferably also comprises a temperature sensor that is used to measure the environment temperature of input side photodetector and outgoing side photodetector environment of living in.If environment temperature changes, the linear relationship between input optical power and the output voltage just might also change owing to the temperature drift in the gain control circuit.Therefore, because when the change in gain that temperature variation causes just can change by correct monitor temperature, adjust the slope of linear relationship or intercept and effectively suppressed (that is, the voltage of comparer being supplied with driving circuit according to the measurement result of temperature sensor is suitably proofreaied and correct).
And image intensifer of the present invention can also contain a gainequalizer between the signal outlet terminal of image intensifer medium and outgoing side coupling mechanism.By place gainequalizer between image intensifer medium and outgoing side coupling mechanism, the light that the outgoing side coupling mechanism is separated (detected object of outgoing side photodetector) is eliminated (lack of uniformity that gains between respective channel is minimized) to the dependence of wavelength.Correspondingly, the channel quantity that just might not consider to introduce the WDM flashlight of image intensifer medium changes, and the WDM signal gain is carried out constant control.
With simpler structure with at a high speed the image intensifer with above-mentioned structure is carried out gain control for example in the gain control circuit of automatic gain control in (being gain control circuit of the present invention), input side photodetector, outgoing side photodetector and comparer preferably contain following circuit component respectively.Particularly, the input side photodetector contains a photo-electric conversion element (first photo-electric conversion element), as phototransformation that the input side coupling mechanism is separated photodiode for the electric current relevant with its power, and the current conversion with photo-electric conversion element output is the operational amplifier (first operational amplifier) of voltage, and this operational amplifier can be adjusted the skew of output voltage.The outgoing side photodetector contains a photo-electric conversion element (second photo-electric conversion element), be converted to the photodiode of the electric current relevant with its power as the light that the outgoing side coupling mechanism is separated, and the current conversion with photo-electric conversion element output is the operational amplifier (second operational amplifier) of voltage, and this operational amplifier can be adjusted the skew of output voltage.Simultaneously, comparer contains a differential amplifier, and it receives and is included in the voltage that the operational amplifier in input side photodetector and the outgoing side photodetector is exported respectively.Differential amplifier is input to driving circuit with the difference of the output voltage of input side photodetector and outgoing side photodetector.The voltage that driving circuit is exported according to comparer (voltage difference) provides drive current to pump light source such as laser diode.
Particularly, in the gain control circuit of the present invention, input side photodetector and outgoing side photodetector have at least one to contain an adjustment mechanism of adjusting offset voltage at least.In other words, in gain control circuit, has one in input side photodetector and the outgoing side photodetector at least to definition input optical power P iAnd output voltage V oBetween the function (V of linear relationship o=aP i+ b) in the b of intercept at least among slope a and the intercept b adjust the corresponding offset voltage of intercept b wherein.
Here, the response time in the gain control circuit preferably also was made as one second or shorter dynamic change to avoid gaining.And in order only the wdm optical signal that will amplify to be carried out gain control, above-mentioned offset voltage adjustment is to carry out under the situation of the noise light (mainly being ASE light) that contained in having considered image intensifer output light.
Except said structure, gain control circuit of the present invention preferably also contains a temperature sensor that is used for measuring the environment temperature of input side photodetector and at least one environment of living in of outgoing side photodetector, to realize constant gain control at temperature variation.
Below, gain control method of the present invention is applicable to that the image intensifer to amplify the WDM flashlight by the image intensifer medium transmission by the pump light that predetermined wavelength is provided from pump light source carries out gain control.
In gain control method of the present invention, be used to define input optical power P iWith output voltage V oBetween the function (V of linear relationship o=aP i+ b) in, slope a and intercept b at first the input side photodetector of the part signal light by being used for receiving input image intensifer medium and at least one of outgoing side photodetector that is used for the part signal light that the reception amplifier medium amplified adjust.Then, this information subtend pump light source of difference with the voltage of being exported from input side photodetector and outgoing side photodetector respectively provides the driving circuit of drive current to control.
At this, in gain control method of the present invention, in order to realize the stable control of gain at temperature variation, driving circuit is this information of voltage difference according to the voltage of being exported from input side photodetector and outgoing side photodetector respectively, and the ambient temperature information of at least one environment of living in is controlled in input side photodetector and the outgoing side photodetector.And constant for the gain amplifier that makes the image intensifer medium, the voltage that going back the subtend driving circuit is provided is adjusted.For fear of the dynamic change of gain, be set in one second or shorter from the photodetection of input side photodetector and outgoing side photodetector to the response time the output adjustment of pump light source.At least one in slope and the intercept is adjusted, to reduce the influence of the noise light that is contained in the image intensifer output light, effect can be better.
Description of drawings
Fig. 1 is the structural drawing of first embodiment of image intensifer of the present invention.
Fig. 2 is the basic block diagram of gain control circuit of the present invention.
Fig. 3 is a design sketch of explaining gain control method of the present invention.
Fig. 4 is the structural drawing of second embodiment of image intensifer of the present invention.
Fig. 5 is the structural drawing that shows the 3rd embodiment of image intensifer of the present invention.
Embodiment
Now, describe the preferred embodiment etc. of image intensifer of the present invention in detail referring to Fig. 1 to Fig. 5.Note that identical member is marked with identical Reference numeral in the description process of accompanying drawing, the explanation of repetition will be omitted at this.
Fig. 1 is the structural drawing of first embodiment of image intensifer of the present invention.As shown in Figure 1, the image intensifer of first embodiment comprises an input side coupling mechanism 110a, an optoisolator 120a, a multiplexer 130, article one, as the Er-doped fiber (EDF) 140 of image intensifer medium, another optoisolator 120b and an outgoing side coupling mechanism 110b, all elements are provided with to outlet terminal 100b from entry terminal 100a according to enumerating order.And this image intensifer also contains a laser diode (LD) 210, and it is the pump light source that the pump light of predetermined wavelength is provided to EDF140, and a gain control circuit.Gain control circuit contains an input side photodetector 200a, an outgoing side photodetector 200b, a comparer 230 that is included in the agc circuit (control system) 240 that is used for carrying out automatic gain control, and a driving circuit 220.
Input side coupling mechanism 110a contains the tributary port of the part of the WDM flashlight that a guiding takes in from entry terminal 100a to gain control circuit.Simultaneously, outgoing side coupling mechanism 110b contains the tributary port of the part of the WDM flashlight that a guiding amplified by EDF 140 to gain control circuit.
Optoisolator 120a has the WDM flashlight by input side coupling mechanism 110a is transferred to EDF 140, blocks the effect from the light of EDF 140 simultaneously.In contrast, optoisolator 120b has the WDM flashlight that EDF 140 is amplified and is transferred to outgoing side coupling mechanism 110b, blocks the effect from the light of outgoing side coupling mechanism 110b simultaneously.
Multiplexer 130 has and will be directed to the effect of EDF 140 with wdm optical signal from the pump light of LD 210.
As mentioned above, gain control circuit contains input side photodetector 200a, outgoing side photodetector 200b, comparer 230 and driving circuit 220.The power P of a light that is separated with input side coupling mechanism 110a of input side photodetector 200a output iVoltage with linear relationship.Simultaneously, the power P of a light that is separated with outgoing side coupling mechanism 110b of outgoing side photodetector 200b output oVoltage with linear relationship.Be included in one of comparer 230 output in the agc circuit 240 respectively from the voltage difference of the voltage of input side photodetector 200a and outgoing side photodetector 200b output.And the output voltage of driving circuit 220 response comparators 230 provides desired drive current to pump light source LD 210.
In this structure, gain control circuit be adjusted into the definition with input side photodetector 200a and outgoing side photodetector 200b at least one relevant input optical power P iWith output voltage V oBetween the function (V of linear relationship o=aP i+ slope a and intercept b in b).At this, in order only the WDM flashlight that will amplify to be carried out gain control, when being adjusted, slope and intercept preferably consider the luminous power of the noise light (mainly being ASE light) that contained in the image intensifer output light.And the dynamic change for fear of gain preferably is made as the response time in this gain control circuit one second or shorter.
Next, Fig. 2 is the basic block diagram of gain control circuit of the present invention.In gain control circuit shown in Figure 2, input side photodetector 200a contains the light that input side coupling mechanism 110a is separated, and (luminous power is P i) being converted to the photodiode PD 201a of electric signal, the offset voltage that can dynamically adjust offset voltage is adjusted machine-processed 203a, and one is used to receive offset voltage and from electric signal and the output and the input optical power P of institute of PD 201a iVoltage V with linear relationship 1Operational amplifier 202a.
Outgoing side photodetector 200b contains the light that outgoing side coupling mechanism 110b is separated, and (luminous power is P o) being converted to the photodiode PD 201b of electric signal, the offset voltage that can dynamically adjust offset voltage is adjusted machine-processed 203b, and one is used to receive offset voltage and from electric signal and the output and the input optical power P of institute of PD 201b oVoltage V with linear relationship 2Operational amplifier 202b.
Comparer 230 contains a reception respectively from the voltage V of input side photodetector 200a and outgoing side photodetector 200b output 1And V 2And export its difference V 3Differential amplifier 231.The voltage difference V that driving circuit 220 will be exported with comparer 230 3Relevant drive current offers LD 210.Like this, power is P PPump light be provided to EDF 140 via multiplexer 130 from LD 210.
Particularly, before the amplification, part signal light is separated by the input side coupling mechanism 110a that is positioned at the image intensifer input side, the voltage V that the power of the light that input side photodetector 200a exports and separated has linear relationship 1In contrast, after the amplification, part optical signals is separated by the outgoing side coupling mechanism 110b that is positioned at the image intensifer outgoing side, the voltage V that the power of the light that outgoing side photodetector 200b exports and separated has linear relationship 2Voltage V from corresponding light electric explorer 200a and 200b output 1And V 2Be input in the differential amplifier 231 in the comparer 230 voltage difference V respectively 3I.e. output since then.Here, for example, can be with operational amplifier, use the differential amplifier etc. of operational amplifier to compare device 230.And driving circuit 220 is according to the voltage difference V of comparer 230 outputs 3The pump energy P of control pump light source LD 210 P, the gain of image intensifer is controlled thus.
Next, the automatic gain control (that is gain control method of the present invention) of gain control circuit shown in Figure 2 described.
At first, the output voltage V of input side photodetector 200a 1Output voltage V with outgoing side photodetector 200b 2Represent by following formula (3) and (4) respectively:
V 1＝R 1·T 1·P i+V o1 (3)
V 2＝R 2·T 2·P o+V o2 (4)
Here, T 1And T 2The transfer ratio (transmittance) of expression input and output side coupling mechanism 110a and 110b respective branch port, P iAnd P oThe optical power value that expression corresponding light electric explorer 200a and 200b are detected, V O1And V O2The offset voltage (intercept) of expression corresponding light electric explorer 200a and 200b, R 1And R 2Expression slope (product of photodetector conversion ratio (A/W) and resistance (Ω)).
Simultaneously, the output voltage difference V of the differential amplifier 231 in the comparer 230 3Represent by following formula (5):
V 3＝K(V 1-V 2) (5)
At this, K represents the gain of differential amplifier 231.
The gain K that supposes differential amplifier 231 is unlimited (that is, desirable comparer) and V O1=V O2, then can derive following formula (6) to formula (5) by aforementioned formula (3):
P OUT/P IN＝(R 1·T 1)/(R 2·T 2)＝G (6)
Here, G represents the gain of image intensifer.
Correspondingly, ideally (in this case, the gain K of differential amplifier 231 is unlimited), the gain G of image intensifer is by R 1And R 2And the transfer ratio T of input and output side coupling mechanism 110a and 110b respective branch port 1And T 2Decision.Yet in the reality, the gain of differential amplifier 231 is not unlimited.Therefore, in gain control method of the present invention, by adjusting the offset voltage V in formula (3) and the formula (4) O1And V O2(offset voltage is adjusted machine-processed 203a and 203b) thus in very wide dynamic range, reach the automatic control of gain.
Here, in gain control circuit shown in Figure 2, can clearly be seen that the variation of light amplifier gain can also be by adjusting and input optical power P from aforementioned formula (6) iAnd output voltage V oBetween linear relationship (V o=aP i+ b) the corresponding R of slope 1And R 2Between ratio, or by adjusting the transfer ratio T of input and output side coupling mechanism 110a and 110b respective branch port 1And T 2Between ratio reach.In this case, also need to adjust the respective offsets voltage V of photodetector 200a and 200b O1And V O2In at least one.In any method of adjustment, different with traditional gain control circuit, this gain control circuit does not need logarithmic amplifier.Therefore, gain control circuit of the present invention can be realized by simpler structure (with lower cost).
Simultaneously, in amplification process, image intensifer usually also can output noise light (mainly being ASE light).Therefore, the light exported of image intensifer had both contained the WDM flashlight that noise light also contains amplification.In image intensifer,, need to eliminate the influence of the noise light that contained in the output light to gain control for the gain amplifier of control signal light accurately.In order to eliminate the influence of noise light, need be from the output voltage V of outgoing side photodetector 200b 2In deduct the difference that equates with noise light power correspondent voltage.Or rather, by adjusting intercept (the offset voltage V in the formula (4) O2) eliminate the influence of noise light.
Next, Fig. 3 is the figure that explains gain control method effect of the present invention.Fig. 3 is that explanation can be by the relativity shift voltage V of corresponding adjustment input side photodetector 200a and outgoing side photodetector 200b O1And V O2Thereby realize the figure of gain control (automatic gain control) in very wide dynamic range.Here, in Fig. 3, when curve G100 is illustrated in the relative adjustment of carrying out offset voltage, the relation between flashlight power input (dBm) and the flashlight gain (dB), the described relation when curve G200 represents that not carrying out offset voltage adjusts.
Be appreciated that from Fig. 3, when not carrying out the adjustment of offset voltage, (curve G200: the situation that does not have relative different between the respective offsets voltage of input side photodetector 200a and outgoing side photodetector 200b) in gain control circuit shown in Figure 2, flashlight power input (dBm) reduces manyly more, and flashlight gain (dB) increases manyly more.On the contrary, in the situation of the offset voltage of the offset voltage of outgoing side photodetector 200b relatively being adjusted to input side photodetector 200a (curve G100), flashlight gain (dB) can almost obtain constant control regardless of the variation of flashlight power input (dBm) in the gain control circuit shown in Figure 2.Therefore, the relative adjustment between input side photodetector 200a and outgoing side photodetector 200b offset voltage is vital for obtaining the high precision gain control in very wide dynamic range.In other words, consideration is input to the power P of the light of corresponding light electric explorer 200a and 200b iWith the plan output voltage V oBetween linear relationship (V o=aP i+ to adjust intercept b b) and relatively be vital.
Note that and to carry out relative the adjustment to the offset voltage of corresponding light electric explorer 200a and 200b.Therefore, if the offset voltage of at least one is adjusted with respect to another offset voltage among photodetector 200a and the 200b, just enough.
Fig. 4 is the structural drawing of second embodiment of image intensifer of the present invention.The image intensifer of second embodiment contains an input side coupling mechanism 110a, an optoisolator 120a, a multiplexer 130, an Er-doped fiber (EDF) 140 that is used as the image intensifer medium, another optoisolator 120b and an outgoing side coupling mechanism 110b, similar to first embodiment, these elements are provided with to output terminal 100b from input end 100a according to enumerating order.And image intensifer also contains a laser diode (LD) 210, and it is the pump light source that the pump light of predetermined wavelength is provided to EDF140, and a gain control circuit of controlling light amplifier gain such as automatic gain control.And, this gain control circuit contains an input side photodetector 200a, an outgoing side photodetector 200b, a comparer 230 that is included in the agc circuit (control system) 250 that carries out automatic gain control, and a driving circuit 220.Structural similarity in the gain control circuit shown in its basic structure and Fig. 2.
Particularly, the image intensifer of second embodiment and the difference of first embodiment be, this image intensifer also has a temperature sensor 260 that is used for measuring the environment temperature of input side photodetector 200a and at least one environment of living in of outgoing side photodetector 200b.Agc circuit 250 among second embodiment has a structure according to the measurement result continuous correction voltage of temperature sensor 260, and this voltage offers driving circuit 220 by the comparer 230 that is included in the agc circuit 250.
When temperature variation, because the temperature drift in the gain control circuit, the relation of formula (3) and formula (4) representative also might change.If the relation of formula (3) and formula (4) representative changes, the gain amplifier of image intensifer also can change.Therefore, the image intensifer of second embodiment (Fig. 4) contains a temperature sensor, so that at temperature variation control is stablized in gain.And, according to measurement result, at least one slope or intercept in agc circuit 250 adjustment formula (3) and the formula (4).Or rather, have the offset voltage that is used for adjusting offset voltage (this offset voltage is corresponding to the intercept of formula (3) and formula (4)) in input side photodetector 200a and outgoing side photodetector 200b one or two of gain control circuit shown in Figure 2 and adjust machine-processed 203a and 203b.Correspondingly, the machine-processed 203a of described adjustment carries out relative the adjustment with 203b by agc circuit 250 and (here, needn't adjust two offset voltages; If an offset voltage is fixed, then only adjust another offset voltage and get final product).
Next, Fig. 5 is the structural drawing of the 3rd embodiment of image intensifer of the present invention.The image intensifer of the 3rd embodiment also contains an input side coupling mechanism 110a, an optoisolator 120a, a multiplexer 130, Er-doped fiber (EDF) 140 as the image intensifer medium, another optoisolator 120b and an outgoing side coupling mechanism 110b, similar with second embodiment to first, these elements are provided with to output terminal 100b from input end 100a according to enumerating order.And this image intensifer also contains a laser diode (LD) 210, and it is the pump light source that the pump light of predetermined wavelength is provided to EDF 140, and a gain control circuit of controlling light amplifier gain such as automatic gain control.And, this gain control circuit contains an input side photodetector 200a, an outgoing side photodetector 200b, a comparer 230 that is included in the agc circuit (control system) 270 of carrying out automatic gain control, and a driving circuit 220.Structural similarity in its basic structure and the gain control circuit shown in Figure 2.
Particularly, the image intensifer of the 3rd embodiment and the difference of second embodiment are that this image intensifer also contains one and places the signal output part of EDF 140 and the gainequalizer (GEQ) 150 between the outgoing side coupling mechanism 110b.In the 3rd embodiment, agc circuit 170 be configured to monitor the flashlight before amplifying and amplify after flashlight, and adjust the offset voltage of input side photodetector 200a and outgoing side photodetector 200b continuously.Yet agc circuit 270 also can adopt the akin structure with first embodiment, and the offset voltage of corresponding light electric explorer 200a and 200b is adjusted in advance.
Gain as the EDF 140 of image intensifer medium has dependence to wavelength.Therefore, because the lack of uniformity of the WDM flashlight gain amplifier that causes of wavelength, the image intensifer of the 3rd embodiment contains a GEQ 150 in order to reduce, and the shape of its loss spectra is identical with the gain spectral of EDF140.Preferably GEQ 150 is placed between the signal output part and outgoing side coupling mechanism 110b of EDF 140.If GEQ 150 is arranged on the downstream (between outgoing side coupling mechanism 110b and output terminal 100b) of outgoing side coupling mechanism 110b, perhaps without GEQ 150, although the WDM flashlight of input image intensifer demonstrates consistent level in the channel of respective wavelength, the light that outgoing side coupling mechanism 110b is separated (detected object of outgoing side photodetector 200b) is still unbalanced at corresponding interchannel.In this case, the gain of control image intensifer makes that the average gain of WDM flashlight is desired value.Correspondingly, the gain of the flashlight on channel may be different from the average gain of WDM flashlight on a plurality of channels.Therefore, if the channel quantity of the WDM flashlight of being imported changes, so, the average gain of WDM signal has also changed.Therefore, gain control circuit will be controlled the gain of image intensifer, so that the average gain that changes has a desired value.As a result, the gain of the WDM flashlight in the respective channel can obtain changing.
Simultaneously, in the image intensifer of the 3rd embodiment, as shown in Figure 5, GEQ 150 places between EDF 140 and the outgoing side coupling mechanism 110b.Therefore, the light that outgoing side coupling mechanism 110b is separated (detected object of outgoing side photodetector 200b) is eliminated (promptly for the dependence of wavelength, the lack of uniformity of each interchannel gain is reduced), therefore, although the quantity of WDM flashlight channel changes, the gain of the WDM flashlight of transmission can be controlled consistently on EDF 140.
Here, if the transfer ratio value T of the respective branch port of input side coupling mechanism and outgoing side coupling mechanism 110a and 110b 1And T 2Wavelength is had dependence, and the gain of each interchannel of the WDM flashlight of being imported will become unbalanced (referring to formula (3) or formula (4)).For example, when the bandwidth of signal wavelength is 30nm, for the change in gain between respective channel being controlled at+1dB or littler, need be with the transfer ratio T of the tributary port of input side coupling mechanism 110a 1Transfer ratio T to the tributary port of the dependence of wavelength and outgoing side coupling mechanism 110b 2Difference to the dependence of wavelength is controlled at ± 1dB/30nm or littler.And, channel wavelength not being produced dependence for the gain of controlling each interchannel consistently, input side coupling mechanism 110a and outgoing side coupling mechanism 110b must adopt transfer ratio value T 1And T 2Wavelength is not had and rely on or be the tributary port of identical value.
Such image intensifer is applicable to the optical communication system of transmission WDM flashlight, more specifically, is applicable to the system with the device that carries out channel separation or channel insertion in the WDM flashlight.
As mentioned above, according to the present invention, in the photodetector that the part of the flashlight after flashlight before amplifying and the amplification is surveyed as electronic signal, carry out prior or adjustment continuously to the linear relationship between input optical power and the output voltage, thereby the output valve of photodetector is used as the input data of gain control.Like this, just can not resemble needs logarithmic amplifier to realize that (it is constant making the gain in the control circuit to linearity control circuit the prior art, institute's input optical power is not had dependence), and carry out high speed gain control with simpler structure (with lower cost).

Claims (22)

1.一种光放大器，包括：1. An optical amplifier, comprising: 一个光放大器介质；an optical amplifier medium; 一个向所述光放大器介质提供预定波长的泵浦光的泵浦光源；a pump light source for providing pump light of a predetermined wavelength to said optical amplifier medium; 一个用于分离输入所述光放大器介质的信号光的一部分的第一耦合器；a first coupler for splitting a portion of signal light input to said optical amplifier medium; 一个和所述的第一耦合器一起将所述的光放大器介质夹在中间的第二耦合器，所述的第二耦合器分离在所述光放大器介质中所放大的信号光的一部分；以及a second coupler sandwiching said optical amplifier medium together with said first coupler, said second coupler separating a portion of the signal light amplified in said optical amplifier medium; and 一个使用与所述的第一和第二耦合器分别分离出来的光的功率有关的信息对所述的光放大器的增益进行控制的增益控制电路，a gain control circuit for controlling the gain of said optical amplifier using information on the power of light separated by said first and second couplers, respectively, 其中，所述的增益控制电路包括：Wherein, the gain control circuit includes: 一个用于输出与所述的第一耦合器所分离出来的光的功率成线性关系的电压的第一光电探测器；a first photodetector for outputting a voltage linearly related to the power of the light separated by the first coupler; 一个用于输出与所述的第二耦合器所分离出来的光的功率成线性关系的电压的第二光电探测器；a second photodetector for outputting a voltage linearly related to the power of the light separated by the second coupler; 一个用于输出所述的第一和第二光电探测器分别输出的电压之间的电压差值的比较器；以及，a comparator for outputting a voltage difference between voltages respectively output by said first and second photodetectors; and, 一个响应所述比较器的输出电压，向所述的泵浦光源提供所期望的驱动电流的驱动电路；a drive circuit that provides a desired drive current to the pump light source in response to the output voltage of the comparator; 其中，所述的增益控制电路具有一种通过调整定义与所述的第一和第二光电探测器有关的输入光功率Pi和输出电压Vo之间线性关系的函数(Vo＝a·Pi+b)中斜率a和截距b而进行增益控制的结构。Wherein, the gain control circuit has a function ( V o = a· P i + b) in the slope a and intercept b to control the structure of the gain. 2.如权利要求1所述的光放大器，其中，所述的第一个光电探测器包括：2. The optical amplifier of claim 1, wherein said first photodetector comprises: 一个用于将所述的第一耦合器所分离出来的光转换为与其功率有关的电流的第一光电转换元件；以及a first photoelectric conversion element for converting the light separated by the first coupler into a current related to its power; and 一个用于将所述的第一光电转换元件所输出的电流转换为电压的第一运算放大器；a first operational amplifier for converting the current output by the first photoelectric conversion element into a voltage; 其中，所述的第二光电探测器包括：Wherein, the second photodetector includes: 一个用于将所述的第二耦合器所分离出来的光转换为与其功率有关的电流的第二光电转换元件；以及a second photoelectric conversion element for converting the light separated by said second coupler into a current related to its power; and 一个用于将所述的第二光电转换元件所输出的电流转换为电压的第二运算放大器，a second operational amplifier for converting the current output by the second photoelectric conversion element into a voltage, 其中，所述第一和第二光电探测器中的至少一个包括一个用于调整要输出的电压的偏移的调整机制。Wherein, at least one of the first and second photodetectors includes an adjustment mechanism for adjusting the offset of the voltage to be output. 3.如权利要求1所述的光放大器，其中所述增益控制电路中的所述比较器含有一个用于接收分别包含在所述第一和第二光电探测器中的所述第一和第二运算放大器所输出的电压的差分放大器。3. The optical amplifier as claimed in claim 1, wherein said comparator in said gain control circuit includes a circuit for receiving said first and second photodetectors included in said first and second photodetectors, respectively. The output voltage of the two operational amplifiers is a differential amplifier. 4.如权利要求1所述的光放大器，还含有一个用于测量所述的第一和第二光电探测器中至少一个所处环境的环境温度的温度传感器，4. The optical amplifier of claim 1, further comprising a temperature sensor for measuring the ambient temperature of at least one of said first and second photodetectors, 其中，所述的第一和第二光电探测器中光功率与输出电压之间的线性关系根据所述温度传感器的测量结果进行校正。Wherein, the linear relationship between the optical power and the output voltage in the first and second photodetectors is corrected according to the measurement result of the temperature sensor. 5.如权利要求1所述的光放大器，在所述的光放大器介质的信号输出端与所述的第二耦合器之间设置一个增益均衡器。5. The optical amplifier according to claim 1, a gain equalizer is arranged between the signal output end of said optical amplifier medium and said second coupler. 6.如权利要求1所述的光放大器，其中，所述的增益控制电路的响应时间为一秒或更短。6. The optical amplifier of claim 1, wherein a response time of said gain control circuit is one second or less. 7.如权利要求1所述的光放大器，其中，所述的增益控制电路进行自动增益控制。7. The optical amplifier of claim 1, wherein said gain control circuit performs automatic gain control. 8.如权利要求1所述的光放大器，其中，对斜率和截距进行调整，以消除所述光放大器输出的光中所含有的噪声光的影响。8. The optical amplifier according to claim 1, wherein the slope and the intercept are adjusted to eliminate the influence of noise light contained in the light output by the optical amplifier. 9.如权利要求1所述的光放大器，其中，所述第一光电探测器中的支路端口的传送系数T1对波长的依赖与所述第二光电探测器中的支路端口的传送系数T2对波长的依赖之间的差的绝对值在带宽为30nm时，为±1dB或更小。9. The optical amplifier of claim 1 , wherein the wavelength dependence of the transfer coefficient T of the tributary port in the first photodetector is similar to the transfer coefficient T of the tributary port in the second photodetector. The absolute value of the difference between the wavelength dependence of the coefficient T2 is ±1 dB or less at a bandwidth of 30 nm. 10.光放大器的增益控制方法，该光放大器通过从泵浦光源提供预定波长的泵浦光，放大在光放大器介质上传输的波长互不相同的信号光，所述的增益控制方法包括下述步骤：10. The gain control method of optical amplifier, this optical amplifier provides the pumping light of predetermined wavelength from pumping light source, amplifies the signal light of the wavelength that transmits on optical amplifier medium and is different from each other, and described gain control method comprises the following step: 调整定义接收要输入所述光放大器介质的信号光的一部分的第一光电探测器和接收所述光放大器介质所放大的信号光的一部分的第二光电探测器中至少一个的输入光功率Pi与输出电压Vo之间线性关系的函数(Vo＝a·Pi+b)中斜率a和截距b中的至少一项；以及Adjusting the input optical power P i of at least one of the first photodetector receiving a part of the signal light to be input into the optical amplifier medium and the second photodetector receiving a part of the signal light amplified by the optical amplifier medium at least one of a slope a and an intercept b in a function (V o =a·P i +b) of a linear relationship with the output voltage V o ; and 使用所述第一和第二光电探测器分别输出的电压的差值信息，控制向所述泵浦光源提供驱动电流的驱动电路。Using difference information of the voltages respectively output by the first and second photodetectors to control a driving circuit that supplies driving current to the pumping light source. 11.如权利要求10所述的增益控制方法，其中，根据第一和第二光电探测器分别输出的电压的差值信息以及第一和第二光电探测器中至少一个所处环境的环境温度信息对驱动电路进行控制。11. The gain control method as claimed in claim 10, wherein, according to the difference information of the voltages respectively output by the first and the second photodetectors and the ambient temperature of the environment where at least one of the first and the second photodetectors is located The information controls the drive circuit. 12.如权利要求10所述的增益控制方法，其中，对要提供给驱动电路的电压进行调整以使光放大器放大介质的放大增益恒定。12. The gain control method according to claim 10, wherein the voltage to be supplied to the driving circuit is adjusted so that the amplification gain of the optical amplifier amplifying medium is constant. 13.如权利要求10所述的增益控制方法，其中，从第一和第二光电探测器探测到光到对所述的泵浦光源的输出进行调整的响应时间设为一秒或更短。13. The gain control method according to claim 10, wherein a response time from detection of light by the first and second photodetectors to adjustment of the output of the pumping light source is set to one second or less. 14.如权利要求10所述的增益控制方法，其中，对斜率和截距中的任意一项进行调整，以消除光放大器输出的光中所含有的噪声光的影响。14. The gain control method according to claim 10, wherein any one of the slope and the intercept is adjusted to eliminate the influence of noise light contained in the light output by the optical amplifier. 15.如权利要求10所述的增益控制方法，其中，所述的第一光电探测器中的支路端口的传送系数T1对波长的依赖与所述的第二光电探测器中的支路端口的传送系数T2对波长的依赖之间的差的绝对值在带宽为30nm时为1dB或更小。15. The gain control method as claimed in claim 10, wherein the dependence of the transfer coefficient T of the branch port in the first photodetector on the wavelength is the same as that of the branch port in the second photodetector The absolute value of the difference between the wavelength dependencies of the transfer coefficient T2 of the ports is 1 dB or less at a bandwidth of 30 nm. 16.如权利要求10所述的增益控制方法，其中，由所述的光放大器介质所放大并由所述的第二光电探测器所探测到的部分光信号对每一波长的不均衡性降低了。16. The gain control method as claimed in claim 10, wherein, the partial optical signal amplified by the optical amplifier medium and detected by the second photodetector reduces the imbalance of each wavelength up. 17.增益控制电路，用于通过从泵浦光源提供预定波长的泵浦光而放大在光放大器介质上传输的波长互不相同的信号光的光放大器，所述增益控制电路包括：17. A gain control circuit for an optical amplifier for amplifying signal lights of mutually different wavelengths transmitted on an optical amplifier medium by supplying pump light of a predetermined wavelength from a pumping light source, the gain control circuit comprising: 一个用于输出与拟输入所述光放大器介质的信号光的一部分的功率具有线性关系的电压的第一光电探测器，所述第一光电探测器含有一个将输入其内的部分信号光转换为与其功率有关的电流的第一光电转换元件，以及一个将所述第一光电转换元件的输出电流转换为电压的第一运算放大器；a first photodetector for outputting a voltage linearly related to the power of a part of the signal light to be input into said optical amplifier medium, said first photodetector having a device for converting a part of the signal light input thereinto a first photoelectric conversion element for a current related to its power, and a first operational amplifier for converting an output current of said first photoelectric conversion element into a voltage; 一个用于输出与所述光放大器介质所放大的信号光的一部分的功率具有线性关系的电压的第二光电探测器，所述第二光电探测器含有一个将所放大的信号光的一部分转换为与其功率有关的电流的第二光电转换元件，以及一个将所述的第二光电转换元件的输出电流转换为电压的第二运算放大器；a second photodetector for outputting a voltage linearly related to the power of a part of the signal light amplified by the optical amplifier medium, the second photodetector having a part of the amplified signal light converted into a second photoelectric conversion element for a current related to its power, and a second operational amplifier for converting the output current of said second photoelectric conversion element into a voltage; 一个用于输出所述第一和第二光电探测器分别输出的电压的电压差值的比较器，所述比较器含有一个接收分别包含在所述第一和第二光电探测器内的第一和第二运算放大器的输出电压的差分放大器；以及，a comparator for outputting a voltage difference between voltages output by said first and second photodetectors respectively, said comparator comprising a first and a differential amplifier of the output voltage of the second operational amplifier; and, 一个响应所述比较器的输出电压，向所述泵浦光源提供所期望的驱动电流的驱动电路，a drive circuit for supplying a desired drive current to the pump light source in response to the output voltage of the comparator, 其中，所述第一和第二光电探测器中至少一个还含有调整至少一个拟输出电压的偏移的调整机制。Wherein, at least one of the first and second photodetectors further includes an adjustment mechanism for adjusting the offset of at least one quasi-output voltage. 18.如权利要求17所述的增益控制电路，其中，所述的增益控制电路具有一秒或更短的响应时间。18. The gain control circuit of claim 17, wherein said gain control circuit has a response time of one second or less. 19.如权利要求17所述的增益控制电路，其中，所述的增益控制电路执行自动增益控制。19. The gain control circuit of claim 17, wherein said gain control circuit performs automatic gain control. 20.如权利要求17所述的增益控制电路，其中，所述的调整机制调整电压的偏移以消除所述光放大器输出光中所含有的噪声光的影响。20. The gain control circuit as claimed in claim 17, wherein said adjustment mechanism adjusts the voltage offset to eliminate the influence of noise light contained in the output light of said optical amplifier. 21.如权利要求17所述的增益控制电路，还含有一个用于测量所述的第一和第二光电探测器中至少一个所处环境的环境温度的温度传感器，其中，根据所述第一和第二光电探测器分别输出的电压的差值信息以及所述温度传感器的测量结果对所述驱动电路进行控制。21. The gain control circuit of claim 17, further comprising a temperature sensor for measuring an ambient temperature of at least one of said first and second photodetectors, wherein, according to said first The driving circuit is controlled by the difference information of the voltage outputted by the second photodetector and the measurement result of the temperature sensor. 22.如权利要求17所述的增益控制电路，其中，所述第一光电探测器中的支路端口的传送系数T1对波长的依赖与所述第二光电探测器中的支路端口的传送系数T2对波长的依赖之间的差的绝对值在波长的宽度为30nm时为1dB或更小。22. The gain control circuit of claim 17 , wherein the wavelength dependence of the transfer coefficient T of the branch port in the first photodetector is the same as that of the branch port in the second photodetector. The absolute value of the difference between the dependence of the transmission coefficient T 2 on the wavelength is 1 dB or less when the width of the wavelength is 30 nm.
CNB031549926A 2002-08-30 2003-08-26 Light amplifier, gain-control method for light amplifier and electric circuit Expired - Fee Related CN1318909C (en)

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
JP255000/2002 2002-08-30
JP2002255000A JP4126994B2 (en) 2002-08-30 2002-08-30 Optical amplifier, optical amplifier gain control method, and optical amplifier gain control circuit

Publications (2)

Publication Number Publication Date
CN1487349A true CN1487349A (en) 2004-04-07
CN1318909C CN1318909C (en) 2007-05-30

Family

ID=34179481

Family Applications (1)

Application Number Title Priority Date Filing Date
CNB031549926A Expired - Fee Related CN1318909C (en) 2002-08-30 2003-08-26 Light amplifier, gain-control method for light amplifier and electric circuit

Country Status (1)

Country Link
CN (1) CN1318909C (en)

Cited By (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
WO2014075271A1 (en) * 2012-11-15 2014-05-22 华为技术有限公司 Optical amplifier control method and device and optical amplifier
CN108956650A (en) * 2017-05-25 2018-12-07 北京君和信达科技有限公司 Detector gain method of automatic configuration, device, system and storage medium
CN112729539A (en) * 2019-10-28 2021-04-30 艾普凌科有限公司 Optical sensor
CN112821184A (en) * 2021-02-02 2021-05-18 徐州诺派激光技术有限公司 Laser frequency-locking PID module
CN113541815A (en) * 2021-09-16 2021-10-22 香港中文大学（深圳） Resonant optical communication device and method based on gain control

Family Cites Families (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPH02308581A (en) * 1989-05-24 1990-12-21 Furukawa Electric Co Ltd:The Light amplification
SE514609C2 (en) * 1996-09-13 2001-03-19 Ericsson Telefon Ab L M System and method for controlling the output power of an optical amplifier
GB2322228A (en) * 1997-02-17 1998-08-19 Northern Telecom Ltd Optical amplifiers and WDM transmission systems
JP2000040847A (en) * 1998-07-23 2000-02-08 Nippon Telegr & Teleph Corp <Ntt> Optical amplifier
US6163399A (en) * 1998-12-08 2000-12-19 Nortel Networks Limited Method and apparatus for suppressing transients in optical amplifiers
US6366395B1 (en) * 2000-03-30 2002-04-02 Nortel Networks Limited Optical amplifier gain control

Cited By (7)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
WO2014075271A1 (en) * 2012-11-15 2014-05-22 华为技术有限公司 Optical amplifier control method and device and optical amplifier
CN108956650A (en) * 2017-05-25 2018-12-07 北京君和信达科技有限公司 Detector gain method of automatic configuration, device, system and storage medium
CN108956650B (en) * 2017-05-25 2021-09-24 北京君和信达科技有限公司 Detector gain automatic configuration method, device and system and storage medium
CN112729539A (en) * 2019-10-28 2021-04-30 艾普凌科有限公司 Optical sensor
CN112821184A (en) * 2021-02-02 2021-05-18 徐州诺派激光技术有限公司 Laser frequency-locking PID module
CN113541815A (en) * 2021-09-16 2021-10-22 香港中文大学（深圳） Resonant optical communication device and method based on gain control
CN113541815B (en) * 2021-09-16 2021-12-21 香港中文大学（深圳） A gain control-based resonant optical communication device and method

Also Published As

Publication number Publication date
CN1318909C (en) 2007-05-30

Similar Documents

Publication Publication Date Title
CN1081858C (en) Optical communication system
JP4498509B2 (en) Control device and control method of wavelength division multiplexing optical amplifier
CN1324395C (en) Hybrid optical amplifier coupling raman fiber amplifier and semiconductor optical amplifier
BR9807355A (en) Optical amplifier device, fiber optic network, and, process to amplify light signals traveling on an optical transmission link
US6975448B2 (en) Automatic gain controller of optical fiber amplifier
CN1916674A (en) Optical transmission device equipped with pluggable variable optical attenuator
US6977770B2 (en) Optical amplifier and control method therefor
WO2015089868A1 (en) Raman pump laser control apparatus and control method therefor
CN100454789C (en) Raman amplified repeater and optical transmission system using the Raman amplified repeater
CN106768269A (en) Fiber-optic hydrophone system based on PGC principles
JP2007081405A (en) Optical amplification device with channel output flattening function
CN1252531C (en) Reman optical fibre amplifier with dynamic gain wave control
CN1487349A (en) Optical amplifier, gain control method and circuit of optical amplifier
US6738185B2 (en) Optical amplifier gain control method for optical amplifier and gain control circuit for optical amplifier
CN2631132Y (en) Mixed broadband optical fiber amplifier
CN101141203A (en) Optical amplifier gain noise compensation apparatus and method for optical transmission system
CN1790954A (en) Apparatus and method for controlling gain of optical receiver in optical communication system
CN1794615A (en) Method of controlling the gain of a raman amplifier
US7239441B2 (en) Raman amplification repeater
CN1264056A (en) Light-wave communication system using semiconductor light amplifier
CN1506740A (en) Optical fiber amplifier with automatic power control function and automatic power control method
JP2000106464A (en) Direct optical amplifying device and method
CN114124240B (en) Optical receiver circuit and optical receiver
KR100358184B1 (en) Hybrid Fiber Amplifier Employing Pump Power Control Loop
CA2423839A1 (en) Raman amplifier

Legal Events

Date Code Title Description
C06 Publication
PB01 Publication
C10 Entry into substantive examination
SE01 Entry into force of request for substantive examination
C14 Grant of patent or utility model
GR01 Patent grant
CF01 Termination of patent right due to non-payment of annual fee

Granted publication date: 20070530

Termination date: 20150826

EXPY Termination of patent right or utility model