Controlling device of optical amplifier and controlling method

0001A control device and the control method of an optical amplifier Technical field

0002Light used in optical fiber communications systems, such as the present invention and a wavelength multiplex lightwave transmission system It is related with the control device and the control method of an amplifier. Background art Ming

0003It is Establishment about an optical amplifier for every [ like and ] prescribed interval well known for the optical fiber communications system. Long-distance transmission is realized by kicking. For example, optical transmission which crosses the Pacific Ocean Writing

0004In the road, it is several 1. One zero piece * number 0 Zero optical amplifier is formed. To this optical amplifier Erbium (Er) A La Placem (Pr), Rare earth Io of thulium (Tm) etc. There is a thing using the optical fiber which added A as an amplification medium, inside -- comparing otherwise High output, high gain, and a broadband are obtained -- optical Huai which doped erbium ion A (EDF: Erbium Doped Fiber) is used well.

0005on the other hand, it follows on the spread of the Internet in recent years, etc. -- passing a network -- transmission the amount of information carried out is carrying out increase mosquito A rapidly -- the further large-scale-izing of transmission systems -- Demand -- , -- Being done . And a wavelength multiplex transmission (WDM: Wavelength Division Multiplex) method is already put in practical use as one of the art which realizes large scale-ization of transmission systems. It is.

0006Several signal lights from which a wavelength differs mutually in these WDM transmission systems (channel) It is multiplexed and is transmitted via one optical transmission way (optical fiber). therefore -- the optical amplifier used in WDM transmission systems and a plurality of signal lights are put in block -- increase -- To be able to carry out width is demanded.

0007Although network composition more flexible than recent years is realized, the OADM (Optical Add-Drop Multiplex) device which can Increase or decrease individually each signal light (Channel) is also used. It has turned, The signal light power transmitted in an optical transmission way does not become fixed. such Change ( naturally this change arises, also when an obstacle arises in some channels) of a number of channels if signal light power is changed sharply -- the signal light of other channels -- normal -- a receiving' recovery -- intermediary Cause [ do / it ].

0008then, case where the number of signal wavelengths of a WDM signal changes in the conventional optical fiber communications system But -- controlling an amplification profit uniformly in an optical amplifier -- output The of each signal wavelength Controlling so that The 1 becomes fixed is performed. this control method -- A G C (Automatic Gam Control) -- when .

0009the output light power of being concrete and an optical amplifier is monitored -- being based on the monitor value -- light Controlling amplification profit of an optical amplifier (in fact for example, excitation light power) so that the output light power of an amplifier becomes fixed is performed.

0010however, input light power is strange in such a conventional control method (AG C) before [ after turning ] controlling the influence appropriately -- one number It was which requires the time about 0 m s Because -- restrictions have arisen in Increase or decrease of the signal light wavelength. Place which the disconnection in an accident, etc. produced The influence of the signal level on other wavelengths will arise over a long time in Synthesis.

0011For this reason, in AG C of an optical amplifier, change of input light power is followed at high speed, and it is at the short time. To be able to carry out the fixed control of the output light power in between is desired. However, speed of response of AG C When high-speed Y is carried out without any restriction, there is a possibility that an oscillation phenomenon may arise.

0012Then, public [ conventionally / No. 200145 / nine to /, for example, Provisional Publication No., ] as the high speed technique of AG C News (it is called the following and patent documents 1) Japanese patent No. 221737 [ seven to ] gazette (it is called the following and patent documents 2) There is art which is proposed.

0013That is, with art given in patent documents 1, it is first, It is about the lightwave signal which should be amplified at the predetermined delay time. It has composition inputted into an optical amplifier (E D F) via the optical fiber which has between, The light to which starting supply of excitation light by the time the signal light reaches E D F, since it detected that signal light arrived at the input edge of Faipa is performed (for example, refer to the paragraph of Patent documents 1 [0 0 3 4;]* [0 0 3 9]). Thereby, it is an important point to excitation light control. While giving a margin by the above-mentioned time delay at time to carry out controls generating of a possible next door, as a result optical serge, it also enables the speed of response of AG C to improve. Regulation for on the other hand offsetting change of input signal light with the art of a statement to patent documents 2 Light is inputted into an optical amplifier as the transmission direction of signal light from an opposite direction, and the regulation light is answered. Output fixed control of an optical amplifier is performed by controlling the excitation light of an optical amplifier. According to this technique, narrowing the range of the input light power of the optical amplifier which should be controlled which can be easily improved in the speed of response of AG C since it can do (for example, refer to paragraph [ of patent documents 2 ] [0 0 1 6] * [0 0 2 7]).

0014However, it is Late about the Trust * light inputted into an optical amplifier in art given in patent documents 1. Since the optical fiber for making it extend is provided too much, it results in inviting characteristic . Inferiority by the optical fiber, and large-sized Y of an optical amplifier. With art given in patent documents 2 High-speed control of regulation light is necessity and To of an optical amplifier according to the regulation optical power concerned again. It results in causing increase of expense electric power and generation of heat.

0015With the present invention, It was originated in view of the above subjects. therefore. input power of signal light -- strange Motion -- oscillation phenomenon, Enlargement of an optical amplifier, This which produces increase Y of power consumption And generation of heat There is nothing and it can follow at high speed. It is offer about a control device and a control method of an optical amplifier. It aims at carrying out. The indication of an invention

0016In order to achieve the above-mentioned object, it is characterized by having offered each means of the control device and the control method of an optical amplifier of the present invention, and the following.

0017(1) It is based on the input light power and output light power of an optical amplifier, and is a profit of this optical amplifier. The 1st control means to control

0018(2) at least [ of the input light power And output light power ] -- responding to any 1 side -- the -- The amount variable means of gain control to which the amount of gain control of this optical amplifier by the control means of The 1 is changed Here, the 1st above-mentioned control means, and the input light power and the output light power -- Based it is and asks for the difference from the target profit of this optical amplifier -- being based on the difference -- the amount of gain control While offering the amount computing unit of gain control for which it asks It is at least either of the input light power And output light power about the coefficient to the above-mentioned amount variable means of gain control, and the difference. The coefficient controller changed according to one side may be offered and constituted.

0019It is Based on to the above-mentioned control means, and the input light power and the output light power of The 1. It asks for the difference from the target profit of a The light amplifier, It is a basis to the integral value of the difference and difference concerned. While offering the amount computing unit of gain control which calculates the About this amount of gain control, it is the above-mentioned profit. The amount variable means of control, They are the input light power and the output light power about the coefficient to the difference. Even if it offers and constitutes the coefficient controller changed according to any 1 side at least It is and is ..

0020It is Based to the above-mentioned control means, and the input light power and the output light power of The 1. It is and asks for the difference from the target profit of this optical amplifier, To the integral value of the difference and difference concerned While offering the amount computing unit of gain control which is based and calculates the amount of gain control, it is the above-mentioned profit. The amount variable means of profitable control, It is each about the coefficient to the difference, and the coefficient to the integral value. It is made to change at least according to either of the input light power And output light power. A Coefficient controller may be offered and constituted.

0021It is based on the control device of this optical amplifier, and the input light power, and is a profit of this optical amplifier. It is System of preparation and above The 1 further about the control means of The 2 which carries out feeding Forward 1 Do control. It is composition so that the profit of an optical amplifier may be controlled by combination of a means and the control means of The 2. It may carry out.

0022When the above-mentioned optical amplifier has the 1st source of excitation light, and a source of excitation light of The 2 Control means of above The 1, the output light power expected from the source of excitation light of this The 1 -- profit Time of there being Re as for nothing, Shortage which calculates the amount of gain control for compensating an insufficiency in the source of excitation light of this The 2 Part deciding part, as opposed to the amount of gain control calculated by this insufficiency deciding part -- Excitation of this The 1 the time of being insufficient with the time of there being enough output light power expected from Source light source -- this difference a part -- the conversion part which gives conversion which does not change the receiving coefficient may be offered. The control devices of the optical amplifier of the present invention are a source of excitation light of The 1, and a source of excitation light of The 2. It is a control device of the optical amplifier which it has, Input light power and output light power of this optical amplifier It is based and asks for the difference from the target profit of this optical amplifier, It is based on that difference and is this light. Preparation and this control means are the 1st source of excitation light about the control means which controls the profit of an amplifier. When the excitation light power to expect is not obtained, An insufficiency is compensated in the source of excitation light of this The 2. Insufficiency deciding part which calculates the amount of gain control of a sake, as opposed to the amount of gain control calculated by this insufficiency deciding part -- time of there being enough excitation light power expected from the source of excitation light of this The 1 conversion which does not change the coefficient to the difference in the time of being insufficient is given -- strange It is characterized by offering a Conversion part.

0023The control method of the optical amplifier of the present invention, Input light power and output light of (1) light amplifier The amount of gain control at the time of controlling the profit of this optical amplifier based on power is calculated, (2) Ask. The input light power And output light power is any 1 side at least about the amount of Said gain control. It is characterized by making it respond and change. .

0024The control methods of the optical amplifier of the present invention are the 1st source of excitation light, and a source of excitation light of The 2. It is the control method of the optical amplifier which it has, Input light Power 1 and output light power of this optical amplifier It is based and asks for the difference from the target profit of this optical amplifier, It is based on the difference and is this light. Excitation light Power which is expected from the source of excitation light of (1) this The 1 in controlling the profit of an amplifier When 1 is not obtained, the amount of gain control for compensating an insufficiency in the source of excitation light of this The 2 -- Demand (2) -- the excitation light power expected from the source of excitation light of this The 1 to the amount of gain control concerned -- leg As [ change / in the time of being insufficient with the time of Riaruto / the coefficient to the difference ] It is characterized by changing. Brief explanation of the drawings

0025Drawing 1 is the Plock figure showing the composition of the important section of the optical amplifier concerning The 1 embodiment of the present invention. It is.

0026Drawing 2 -- a figure -- it is the Plock figure showing the composition of the control part shown in 1.

0027The required feeding pack coefficient and Yield to the input light power which requires Drawing 3 for this embodiment It is a figure showing a relation with a bunch limit.

0028Drawing 4 -- a figure -- composition of the Phi 1 Back control part And Phi 1 Deep pack coefficient control part shown in 2 It is a shown block diagram. ■

0029Drawing 5 -- a figure -- it is the Plock figure showing the The 1 modification of the Phi 1 Back control part And Phi 1 Deep pack coefficient control part shown in 4.

0030Drawing 6 -- a figure -- it is the Plock figure showing the The 2 modification of the Phi 1 Deep pack control part And Phi 1 Deep pack coefficient control part shown in 4.

0031Drawing 7 is the Plock figure showing the composition of the control part of the optical amplifier concerning The 2 embodiment of the present invention. It is.

0032Drawing 8 -- a figure -- it is the Plock figure showing the composition of a Defoed [ The Phi 1 Deep pack control part shown in 7, and feeding pack coefficient control part And Phi - ] control part.

0033Drawing 9 -- a figure -- it is the Plock figure showing The 1 modification of a Defoed [ The Phi 1 Deep pack control part shown in 8, and feeding pack coefficient control part And Phi - ] control part. Drawing 1 0 -- a figure -- the Phi 1 Deep pack control part shown in 8, and feeding pack coefficient control part Oopifu It is the Plock figure showing The 2 modification of a Eidfo 1 Do control part.

0034Drawing 1 Plock figure showing the composition of the important section of the optical amplifier which requires 1 for The 3 embodiment of the present invention it is .

0035Drawing 1 2 -- a figure -- 1 It is the Plock figure showing the composition of the control part shown in 1.

0036Drawing 1 3 -- a figure -- 1 It is the Plock figure showing the modification of the control part shown in 3.

0037Drawing 1 4 is excitation light power control. (with no amendment) They are an excitation light control value and excitation light The that it should explain. It is a figure showing a relation with The 1.

0038Drawing 1 5 -- a figure -- 1 Excitation light power control by the control part shown in 2 (those with amendment) Explain It is a figure showing the relation between a Excitation optical control value and excitation light Power 1. The best form for inventing

0039[A] Explanation of The 1 embodiment

0040Optical amplifier 1 shown in this Drawing 1 in the Plock figure showing the composition of the important section of the optical amplifier which requires Drawing 1 for The 1 embodiment of the present invention, optical branching filter 2, 3, 6, and an erbium-doped optical fiber (E D F) -- 4, gain equalizer 5, photosensor 7, 9, source 8 of excitation light, and a control part (System device) -- 1 0 is offered and it is constituted.

0041here -- optical branching filter 2 -- optical transmission way It is received from 2 0. WDM signal light (the main signal light) branching a part -- one side while outputting to a E D F 4 side -- another side -- Power monitor's For -- as Moyuta light -- photosensor It outputs to 7. optical branching filter. 3, Optical branching filter the main signal light from 2 -- source of excitation light Excitation light supplied from 8 (pump light) It was to combine Because -- it is a thing.

0042E D F 4, Optical multiplexing machine What amplifies the main signal from 3 by the above-mentioned excitation light It is. gain equalizer 5, this -- Profit of the amplification output of E D F 4 (gain) main -- the profit of each wavelength of signal light -- equalization (flat-izing) It is for carrying out. Optical branching filter 6, This gain equalizer. It branches in a part of equalization output of 5, It is an optical transmission way of an output side about one side. While outputting to 3 0, it is a photosensor considering another side as a monitor light for a power monitor. It outputs to 9.

0043On the other hand Photosensor 7, Optical branching filter A monitor light branched by 2 is received and it is the Acceptance. An electric signal according to light volume (power) is generated. photosensor. 9 is the same. Optical branching filter receiving a monitor light branched by 6 -- the light income (power) It responded. An electric signal is generated. Also any, For example, Photo-diode (PD) Configuration is carried out. That is, the input light measuring means which measures the above-mentioned photosensor 7 and the input light power of EDF 4 which functions as an optical amplifier, photosensor 9, and output light The of EDF4 It functions as an output light measuring means which measures Wow, respectively.

0044Source 8 of excitation light is compared by the thing for generating the excitation light for EDF 4. It is constituted by The and laser diode (LD).

0045And control part 1 0, each of above-mentioned photosensors 7, and power measurement result by 9 (input light power And output light power) It is based and the excitation light power of source 8 of excitation light is controlled, It is fixed control about the profit of EDF 4. (A G C: Automatic Gain Control) Thing for carrying out Although it is, It can follow enough also to change with input light power rapid in this embodiment. The device for improving the speed of response of the method of To and the AG C control from before is made. being concrete and control part 1 of this embodiment 0, for example, a figure, -- as [ show / in 2 ] -- Feed pack control part 1 1 And feeding pack coefficient control part 1 2 is offered and it is constituted.

0046Here, it is a feeding pack control part. (control means of The 1) 1 1, photosensor 7, and 9 It is based on input light Power 1 and output light Power 1 which were monitored, respectively, and is a profit of E DF 4.

0047(Namely, excitation light power) Are concrete what calculates the amount of control at the time of carrying out feeding pack control, for example, intermediary To have [ as ] which calculates the amount of control by following formula (1).

0048LD_0Ul=ax(P_inxG-P_0Ul)-(l)

0049LD_0Ut: Excitation light power

0050: Input light power

0051P_outOutput light power

0052G: Target profit

0053for this reason, feeding pack control part 1 1, for example, a figure, -- as [ show / in 4 ] -- input light ParP_inMultiplier 1 which multiplies target profit G From the multiplication result to 1--3 and output light Power P._utsubtraction machine 1 which subtracts and asks for difference It is [ 1--2 and ] feeding to the obtained difference. Multiplier 1 which multiplies back coefficient a and calculates an excitation light control value 11 -- offering 3 -- composition It is carried out. That is, multiplier 1 1, subtraction machine 11--2, and multiplier 11--3 of these are based on the input light power and output light power of optical amplifier 1, and are the difference from target profit G of optical amplifier 1. 1 -- (input light power P)_inX target profit G -- Output light power P._utit asks -- the difference a part -- since the function as an amount computing unit of gain control for it to be based and to calculate the amount of gain control is achieved -- is there.

0054Here, in order to perform early feeding pack control of a reaction, it is the above-mentioned formula (1). Although coefficient (feeding pack coefficient) a which can be set may be enlarged, it is a nothing system about this coefficient a. If it enlarges, the output of EDF 4 will oscillate and it will not converge on Limit. especially -- light In E DF well used as an amplifier, cause an oscillation for the characteristic. I am easy, so that it can follow enough also to a rapid change of input light power -- phi Dove Large The coefficient a cannot be taken.

0055However, the transient phenomenon of EDF 4 to change of excitation light power is taken into consideration, and it is ON. Up in the state where it does not oscillate by using feeding pack coefficient a according to output light power High-speed control is realizable from Up. EDF4 -- input light power and letter of an oscillation Coefficient (convergence limit) a which becomes purposely, and sufficient performance (high-speed response performance) the relation with securable coefficient a -- a figure -- it comes to be shown in 3. this figure -- coefficient a is enlarged as shown in 3 In a place with necessity, it turns out that it has the characteristic which is hard to oscillate.

0056So, at this embodiment, it is a feeding pack coefficient control part. (the amount variable means of gain control) Input light power P monitored by 12 by photosensor 7 in feeding pack coefficient a_inIt is alike, and responds and controls. (variable) It carries out. Must specifically shown all over Drawing 3 as shown in Drawing 4 Function f i (function computing unit 12--1) of Essential feeding pack coefficient a It controls. Here, it can express with function f i of required feedback coefficient a shown all over Drawing 3, for example, following formula , (2).

0057f<img file="WO2004040719A1_D0001.tif" />X convergence limit -- (2)

0058It sets at this ceremony (2), As for "b", although it is or more 0 less than one constant, how much is this? It is decided by whether high-speed response performance is required. moreover It can express with following formula (3) the case where a profit of about 20 dB is given to "a convergence limit, for example, EDF4."

0059'convergence marginal D. /! ^ ... (3)

0060Therefore, function f i f! = b C Pin -- (4)

0061It can express. However, above-mentioned formula (3), It can set to (4). "rho_*" -- input light Power, "c" expresses the constant decided by the E D F characteristic or a profit, respectively. ON the case where power light power is small, if this formula (4) is used as it is, feeding pack coefficient a will become large -- since a response is too high-speed or an arithmetic circuit becomes complicated Input light power In a small place, feeding pack coefficient a is fixed or the value of "b" is changed. In some cases, it is better for it to have been sufficient and to carry out.

0062Each of control parts 1 above-mentioned by a small logic circuit etc. 1 and 1 When it mounts 2, the division of the above-mentioned function f i can be realized by giving function f i to necessary memories, such as RAM, as De of table form - Tha, and mounting it, although realization becomes difficult. By above-mentioned composition, it is optical amplifier 1 (E D F 4) with optical amplifier 1 of this embodiment. Input light power P in and output light power P_outWhen -- in Respectively photosensor 7 and 9 -- measurement it is carried out -- feeding pack control part 1 Input light PowerP measured in 1_inOutput Light power P_inWhen -- it being alike and being based -- the difference (input light PowerP) from target profit G_inX target profit G 1 output light power P._utsubtraction machine 1 the difference obtained by being asked by 1--2 -- phi Deep pack coefficient a can take advantaging with multiplier 11_3 -- an excitation light control value is calculated. And the above-mentioned feeding pack coefficient a is feeding pack coefficient control part 1 2 (function input light power P) this time._init is alike, and is responded and changed Below "convergence limit" necessity -- it becomes sufficient value -- high-speed [ without producing an oscillation phenomenon ] in AG C of E D F 4 It can change. In particular, at this example, it is feedforward control section 1. Off by 3 Since it carries out by combining Eidfo 1 Do control, high-speed A G C is realizable. Therefore, signal over optical amplifier 1 used in WDM transmission systems To input power change of light, increase of enlargement of an oscillation phenomenon and an optical amplifier, power consumption, and generation of heat it can follow at high speed, without producing-izing -- output power change of optical amplifier 1 can be controlled. Wavelength (Channel) specifically used as a signal light When a number is changed, output power change of each signal light is made small. It can do. As a result, conventionally stable WDM optical communications are realizable.

0063(A 1) Explanation of the 1st modification

0064control part 1 which mentioned Drawing 5 above 0 (the number control part 1 of feeding pack control part 1 1 And Phi 1 Deep pack charge 3) it is the Plock figure showing The 1 modification -- this figure -- 5 a figure -- style shown in 4 comparing with Formation -- feeding pack control part 1 Multiplier 1 which 1 mentioned above 1 -- 1 and 1 11 -- 3 and subtraction machine 1 1--2 -- in addition, integration machine 1 1 -- 4 and multiplier 1 1--5 and adding machine 1 11 -- it differs in that 6 is further offered. other components (what attached same numerals as numerals as stated above) the same as that of a thing as stated above, unless it refuses especially, respectively -- or -- the same -- After being a thing, also in a modification, it is the same.

0065here, Integration machine 1 -- 1--4, Subtraction machine 1 -- it is what integrates with difference obtained by 1--2 There and multiplier 1 1 1 -- 5, This integration machine 1 -- product about the above-mentioned difference obtained by 1--4 a part -- a value -- a predetermined coefficient is multiplied. adding machine. 1 -- 1--6, This multiplier A multiplication result of 1 5, and multiplier 1 -- a multiplication result of 1-3 is added an excitation light control value -- also asking -- It is that.

0066that is, feeding pack control part 1 of this example Each component 1 of 1 11 -- 1*1 11 -- input light power P of 6 and optical amplifier 1_inOutput light power P_outWhen -- it being alike and being based -- difference of target profit G to (input light power P)_inX target profit G -- Output light power P._utit asks -- the difference The amount Act of gain control which calculates the amount of gain control of optical amplifier 1 based on the integral value of the difference concerned It functions as Calculator.

0067if the same operation effect as the embodiment mentioned above is obtained also by such composition Together -- the embodiment mentioned above -- comparing -- stable AG C is realizable.

0068(A 2) Explanation of the 2nd modification

0069control part 1 which mentioned Drawing 6 above 0 (the number control part 1 of feeding pack control part 1 1 And Phi 1 Deep pack charge 3) it is a block diagram showing The 2 modification -- this figure -- 6 Figure It was shown in 5. It compares with composition and is feeding pack coefficient control part 1. It adds to function of the 2 power above (function computing unit 1 2 - 1), and is function f.₂While offering (Function computing unit 1 2 -- 2), it is the function f.₂Output -- feeding pack control part 1 Multiplier 1 of 1 1--5 -- integration machine 1 11 -- appearance of 4 It differs in that it has power and composition multiplied.

0070Here, it is the above-mentioned function f.₂Is and function mentioned above The values of "C" which can be set only differ. which is a function (it changes with the E D F characteristic, profits, amplifier composition, etc.). that is, this example Then. -- feeding pack control part 1 it sets to 1 -- subtraction machine 1 Difference obtained by 1--2 Not only integration machine 1 11 -- coefficient by which it multiplies also about the integral value of the difference obtained by 4 since it changes according to input light power Pin by function f 2 -- is there.

0071therefore, the operation effect same [ this case ] as the embodiment and The 1 modification which were mentioned above what is shown in Drawing 5 while being obtained -- comparing -- a high speed and stable AG C It is realizable.

0072[B] Explanation of The 2 embodiment

0073Plock figure showing the composition of the control part of the optical amplifier which requires Drawing 7 for The 2 embodiment of the present invention it is -- control part 1 shown in this Drawing 7 0 is compared with what is shown in Drawing 2 -- feeding Forward 1 Do control part 1 3 and adding machine 1 It differs in that 4 is further offered.

0074Here, Feeding Forward 1 Do control part (control means of The 2) 1 3 Photosensor 7 Monitored input light power It responds to P in and is feeding Forward 1 Do control about excitation light Power. The amount of control at the time of carrying out (excitation light control value) It asks. Power U Calculator. 1 4, Each control part It reaches 1 1. An excitation light control value calculated by 1 3 is added, and it is excitation light as an excitation light control signal. Source 8 is supplied.

0075it is concrete -- in this case -- for example, a figure -- as [ show / in 8 ] -- feeding pack control part 1 The multiplier 1 as a thing as stated above with 1 [ same ] 1 -- 1 and 1 113 And subtraction machine 1 11 -- offering 2 Are constituted. feeding pack coefficient control part 1 The function ￡ (Function calculator 1 2 -- 1) as a thing as stated above with 2 [ same ] it is offered and constituted -- further -- feedforward control section 1 3 Feeding Forward 1 Do function f₃(Function computing unit 1 3 - 1) is offered, and it is constituted. feeding Forward 1 -- function used for feed-forward control with publicly known Do function f 3 it is -- .

0076that is, control part 1 of this embodiment 0 and feeding pack control part 1 1 and Feed feed control part 1 the profit of optical amplifier 1 is controlled by combination of 3 -- as -- composition -- It is that of Being done. this compares with a 1st embodiment -- it becomes possible to accelerate A G C of optical amplifier 1 further, without producing an oscillation phenomenon.

0077in addition -- such -- feedforward control section 1 when using 3, it is also the same as that of the composition mentioned above by Drawing 5 and figure 6, for example, a figure, -- 9 and Drawing 1 it is shown in 0, respectively -- as Deep pack [ Phi - ] control part 1 1 -- subtraction machine 1 11 -- the integral value of the difference obtained by 2 -- phi good also as composition used for Deep pack control -- it carries out -- in power or Configuration, it takes advantaging of an integral value a coefficient -- function f₂It is good also as composition which is boiled and is made variable more. It is optical amplification any case. It becomes possible to be stabilized more and to carry out AGC of vessel 1 at high speed.

0078[C] Explanation of The 3 embodiment

0079Drawing 11 is the Plock figure showing the composition of the important section of the optical amplifier concerning The 3 embodiment of the present invention. Optical amplifier 1 shown in this Drawing 11, Figure It compares with what is shown in 1, and is plurality (here). Two sources 8 of excitation light -- 1, 8 -- While 2 is provided, Source 8 of excitation light -- It generates by 2. It differs in that optical multiplexing machine 3' for inputting the excitation light carried out into E D F 4 from the back of E D F4 is formed between E DF 4 and gain equalizer 5.

0080And the feeding pack system as what is shown in Drawing 2 also with same control part 10 in this case Although part 11 and feeding pack coefficient control part 12 are offered, in this case -- as Phi 1 Deep pack control part 11 -- a figure -- as [ show / in 12 ] -- function f 4 (current value Computer 11 A -- 7) and function f₅(Current value computing unit 11 B -- 7), function f c (conversion computing unit 1 1 B -- 8), and limiting circuit 11A -- 8, 11 B -- 9 is offered and it is constituted. multiplier 11 -- 1 and subtraction machine 11 -- 2 and multiplier 111 -- 3 and function respectively -- previous statement It is the same as that of a thing, or the same.

0081Here, it is the above-mentioned function f.₄(Current value computing unit 11 A-7) it mentioned above -- as -- multiplier 111 -- from the excitation light control value calculated by 3 -- on the other hand -- source 8--1 of excitation light of (The 1) -- Drive it is what calculates the current value for carrying out Motion -- limiting circuit 11 A -- 8 and this function f₄When the current value come out of and calculated is over the tolerance level of source 8 of excitation light, it is inside of the tolerance level concerned (below the maximum). It is for stopping.

0082However, this limiting circuit 11 A -- 8, According to this embodiment, it asked function f 4. When the current value is over tolerance level, From the current value which should be outputted essentially to the above-mentioned maximum The deducted current value is one source 8 of excitation light. -- It corresponds to the insufficiency of the excitation light power by 1. Current value (henceforth an insufficient current value) to carry out It carries out and is function f c (conversion computing unit 11 B-8). It is supplied. that is, this limiting circuit 11 -- the time of the excitation light power expected from A--8 and source 8--1 of excitation light not being obtained -- other sources 8 of excitation light -- 2 -- That Achieve the function as an insufficiency deciding part to calculate the amount of gain control for compensating an insufficiency. it is .

0083Next, the above-mentioned function f₅(Current value computing unit 11B -- 7), function f₄being the same and the above source 8 of excitation light of an excitation light control value to another side -- In order to calculate the current value for driving 2 it is a thing -- function f c 1 1 B -- [conversion computing unit [ (conversion part) ] -- 8] and this function f₄Obtainable with -- having had -- a current value and limiting circuit 111 -- the above-mentioned insufficient current value supplied from 8, 1 Source 8 of Excitation Light of Direction -- Insufficiency of Excitation Light Power by 1 -- Source 8 of Excitation Light of Another Side -- Excitation of 2 Time of Trying to Compensate with Light Power, the above-mentioned insufficient current value -- source 8 of both excitation light -- 1 and 8 -- 2 -- One Amendment which does not change feeding pack coefficient a which is (conversion) Thing for giving it is .

0084Being concrete and output of this function f c (conversion computing unit 1 1 B -- 8) (current value) 1₃Is and function f₅It is I about Output.₁It is an insufficiency current value 1₂If it carries out, it is a table at following formula (5). It is carried out.

0085f c = I₃= I i + dX I₂-- (5)

0086It is function f when there are not this formula (5) and an insufficient current value.₅the current value come out of and calculated -- the -- as -- source 8 of excitation light -- Become a driving current value of 2. When other, it asks by function f 5. It is Addition about the insufficient current value amended so that feeding pack coefficient a might not change to a Current value. It is excitation light field 8 which carried out Calculation. -- It means becoming a driving current value of 2. selected so that feeding pack coefficient a may become the same by "state 1" which "d" in this formula (5) reaches figure 14, and is shown all over Drawing 15, and "state 2" (it asks simply by survey and To is made). If it does in this way In "state 1" and "state 2", it is an oscillation limit. It can be made the same.,

0087Drawing 14, Source of excitation light 8 -- 1 and source of excitation light 8 -- The maximum output of 2 is the same, And source of excitation light 8--1 and source of excitation light 8 -- Two output power (excitation light power) 2 : 1 When controlling to become, The above-mentioned function Excitation when not performing amendment by f c Optical control value (driving current value) Source of excitation light 8 [ It is shown. ] -- 1, 8 -- Relation with each excitation light power of 2 Drawing 15 is the above-mentioned function. Excitation light control value when amendment by f c is performed (driving current value) Source of excitation light 8 [ To. ] -- 1, 8 -- A relation with each excitation light power of 2 is shown.

0088namely, the case where amendment by the above-mentioned function * c is not performed -- a figure -- as [ show / in 14 ] each excitation light power denoted by solid line 20 and 21 according to "A state voice 1" -- increase of an excitation light control value -- Accompany Although it increases to Linear In "state 2", while shows as solid line 20, and it is source 8-1 of excitation light. Excitation light power (driving current value) Limiting circuit 1 1 A -- It is maintained by 8 at the maximum, Solid line 2 Source 8 of excitation light of another side shown by 1 -- It turns out that it increases to alignment by the same inclination as "A state voice 1" until the excitation light power of 2 reaches the maximum.

0089On the other hand, when amendment by the above-mentioned function f c is performed, Drawing 1 It is solid line 2 in five. As [ show / 1 ] In "state 2", bigger than inclination by "state 1" -- inclining and coming out -- excitation the excitation light power of light source 8_2 increases -- source 8 of excitation light -- Insufficiency of the excitation light power of 1 Source of excitation light 8- It turns out that it is compensated by the excitation light power of 2.

0090Drawing 1 Limiting circuit 1 shown in 2 1 B -- 9 and the above-mentioned limiting circuit 1 1 A -- It is the same as that of 8. Output of this function f c (current value) Source 8 of excitation light -- Place exceeding the tolerance level of 2 It is inside of the tolerance level concerned to Synthesis. (below the maximum) It is for stopping.

0091By the above composition, it is control part 1 of this embodiment. 0 (feeding pack control part 1 1), Until the excitation light power of source 8--1 of excitation light reaches the maximum (figure 1 between "state 1" shown in 5) source 8 of both excitation light -- 1 and 8 -- the excitation light power of 2 -- Drawing 1 Inside of five Solid line 2 0 and 2 1 shows -- as It is a function, respectively. Good according to input light power Excitation light control value calculated using feeding pack coefficient a by which strange was carried out (multiplier 1 11 3 outputs) It is controlled by the basis.

0092on the other hand, source 8 of excitation light -- After the excitation light power of 1 reaches the maximum (figure 1 5 between To indicate "state 2") Is Source 8 of excitation light -- It is maintained by the maximum and the excitation light power of 1 is This. Insufficiency by Re (limiting circuit 1 1 A -- insufficient current value calculated by 8) It is Supplement with function f c. It is function f while being corrected.₅being added to the current value come out of and calculated -- excitation light source 8 -- the excitation light power of 2 -- solid line 2 in Drawing 15 As [ show / 1 ] the feeding pack coefficient a same at "state 1" and "A state voice 2" -- and insufficiency by source 8--1 of excitation light It increases so that it may compensate.

0093Thus, according to this embodiment, it is source 8 of excitation light of plurality [ amplifier / 1 / optical ]. -- 1 and 8 - 2 is used, One source 8 of excitation light -- Other excitation when the excitation light power of 1 runs short Light source 8 -- Also in the case where the insufficiency is compensated with the excitation light power of 2, an oscillation limit is different State is lost seemingly -- stable AG C can be carried out, without producing an oscillation phenomenon.

0094It is each source 8 of excitation light in this case. -- 1, 8 -- Control part 1 common to 2 Good [ in feeding pack coefficient a / according to input light power ] by 0 (feeding pack control part 1 1) Since it is made strange, source 8_1 of excitation light, and 8 -- it is not necessary to provide an individual control part for every two -- high-speed AGC is realizable at low cost.

0095the amendment function of an excitation light power insufficiency mentioned above -- a figure -- 1 as [ show / in 3 ] -- feeding pack coefficient a is fixation (it does not have function f i) The existing feeding pack system Part 1 even if it applies to 1 . OK, Phi Dofo mentioned above in a 2nd embodiment Word control part 1 Control part 1 which offered 3 Applying to 0 is also possible.

0096At the example mentioned above, it is excitation light ? field 8. -- It is Excitation when the excitation light power of 1 runs short. Stimulation 8 -- Although it is a case where the insufficiency is compensated with the excitation light power of 2, of course -- reverse -- excitation light source 8 -- the case where the excitation light power of 2 runs short -- source 8 of excitation light -- the excitation light power of 1 -- the -- It is also the same as when compensating an insufficiency.

0097At the example mentioned above, it is source 8 of excitation light. -- 1, 8 -- Although arranged in the form where 2 sandwiches E D F 4 at the input-and-output side of E D F, it arranges only to either of the input side And output sides. It may be carried out. the number of the sources of excitation light is not restricted to two, either -- three or more are arranged There is also a To case.

0098CD) In addition to this

0099it is not limited to the present invention, each embodiment mentioned above, and its modification -- the present invention In the range which does not deviate from the meaning, it can change variously and can carry out.

0100for example, -- the example mentioned above -- feedback control part 1 it sets to 1 -- difference or difference although the case where control using the integral value was performed was explained -- these and difference -- fine -- a part -- a value -- control using combination can be carried out.

0101At the example mentioned above, it is feedback control part 1. The feeding pack staff in 1 Although the composition which makes several a variable according to the input light power of optical amplifier 1 was explained, For example, it responds to the both sides of output light power or input light power, and output light power, and is To to variable. It is good as for a method of To. Industrial applicability

0102as mentioned above The present invention The time of controlling a profit of an optical amplifier, Optical amplifier It responds to at least 1 side of input light power And output light power. Good in the amount of gain control It is made strange. To therefore, input power change of signal light, Oscillation phenomenon, Enlargement of an optical amplifier, Consumption Without it produces electric power and increase-ization of generation of heat It can follow at high speed, Stable Optical communications carried out are realizable., Therefore, in the optical-communications field, it reaches to an extreme of the usefulness. It is considered a high thing.