CN1189724A - Optical fiber amplifier - Google Patents
Optical fiber amplifier Download PDFInfo
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- CN1189724A CN1189724A CN97126139A CN97126139A CN1189724A CN 1189724 A CN1189724 A CN 1189724A CN 97126139 A CN97126139 A CN 97126139A CN 97126139 A CN97126139 A CN 97126139A CN 1189724 A CN1189724 A CN 1189724A
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Abstract
An optical fiber amplifier is disclosed including: an optical line through which an optical signal is transmitted; a rare-earth-doped fiber, doped with a predetermined rare earth ion, being set on the optical line; a pumping light beam source for generating a pumping light beam having a predetermined wavelength; a first multiplexer for coupling the pumping light beam to the optical line; a second multiplexer for dividing the pumping light beam outputted from the rare-earth-doped fiber; and pumping light beam looping means for looping the pumping light beam divided by the second multiplexer back to the rare-earth-doped fiber.
Description
The present invention relates to be used for the fiber amplifier of amplifying optical signals, particularly, relate to by looping back the fiber amplifier that this rear-earth-doped optical fiber reduces the Active Optical Fiber amount of formation fiber amplifier and improves amplification efficient simultaneously by feedback control loop or reflection loop as the pump beam of the pumping signal in the rear-earth-doped optical fiber.
Made by the optical communication technique of Optical Fiber Transmission information and widely application.Can high-speed transfer the optical communication technique of bulk information be applied in the international information communication by submarine cable, be stranded the signal that not caused by electromagnetic induction for them and disturb and cross (talk).Owing to developed the multiplexed and network technology that is used for optical communication recently, optical communication technique is little by little expanding their range of application to the sound that comprises between the change over switch and data communication, cable TV or video on demand (VOD) in the important traffic network of interior high-speed wideband multimedia communication.Along with the development of high-speed optical signal transmission with the optical signal amplifier of extra long distance transmission is provided, optical communication technique is improved.Carried out energetically recently about amplifier with the flat gain wavelength that is used in the wavelength multiplexing and the research that is used for the high-gain amplifier of visual distribution technique.
Early stage optical signal amplifier converts light signal to the signal of telecommunication by the avalanche-type photodiode and amplifies, and uses pump diode to convert the signal of telecommunication that amplifies to light signal again.Present optical signal amplifier adopts rear-earth-doped optical fiber, therefore can omit the signal conversion process that light signal amplifies.Above-mentioned rare-earth doped optical fibre is to constitute in the mode such as rare earth ion doped Active Optical Fibers such as Er, Pr and Nd.When the pump beam that will have predetermined wavelength offers rear-earth-doped optical fiber,, finally amplified light signal by corresponding spread fiber just owing to the stimulated photon with predetermined wavelength is launched in the excitation of rare earth ion.
Fig. 1 shows the configuration of the traditional fiber amplifier that adopts rear-earth-doped optical fiber.Referring to Fig. 1, light signal S is coupling on first optical link 1, and pump beam P is coupling on second optical link 2, and first and second optical link 1 and 2 is coupling on the multiplexer 3 as its input.The 3rd optical link 4 of the output that is applied to multiplexer 3 is connected on the 4th optical link 7 as outlet line by rear-earth-doped optical fiber 5 and isolator 6.In this configuration, light signal S and the pump beam P that applies by first and second optical link 1 and 2 respectively is coupled mutually with multiplexer 3, so that they are included in the 3rd optical link 4 corresponding to the output of multiplexer 3 together.
Light signal S and pump beam P act on the rear-earth-doped optical fiber 5, and pump beam P excitation therein is entrained in rare earth ion wherein, are subjected to pumping with what generation had a predetermined wavelength.This light introduced among light signal S and realize light amplification.Isolator 6 prevent with on light signal S opposite direction, advance and comprise such as introducing rear-earth-doped optical fiber 5 from the reflected signal of pump beam that is arranged in another rear-earth-doped optical fiber of next stage or light signal S.
According to length, the wavelength of pumping and the output of pumping of the optical fiber of the concentration that is doped to dopant in the optical fiber, dopant, doping, determine the peak power output of fiber amplifier.Owing to be doped with the optical fiber of rare earth ion is very expensive, and it needs to shorten.Yet become more in short-term when rear-earth-doped optical fiber, just be not enough to carry out the amplification of light signal, thereby and can not get best light signal.
Moreover, for for the light signal of Optical Fiber Transmission, as the pump beam of the exciting light in the rear-earth-doped optical fiber corresponding to noise signal.Thereby the residual pump transmission of staying in the rear-earth-doped optical fiber in order to prevent from not consume is passed through optical fiber, and traditional fiber amplifier comprises a speculum and comes anti-pump beam on its output.Yet, the pump beam of just not exporting of mirror reflects from rear-earth-doped optical fiber, some is by the light signal of Optical Fiber Transmission.Thereby, might reduce the output energy level of light signal.
Thereby the present invention points to the fiber amplifier eliminate one or more problems that restriction and shortcoming by correlation technique cause in fact.
Purpose of the present invention is for providing significantly the fiber amplifier of the length that shortens wherein employed rear-earth-doped optical fiber.
Another purpose of the present invention does not use speculum just can prevent the fiber amplifier of residual pump beam from fiber amplifier output for providing.
Another object of the present invention is promoted the fiber amplifier of the efficient of the electrical power of being utilized for providing by optimizing its amplification efficient.
Further feature of the present invention and advantage will state in the following description, and a part wherein will be conspicuous from explanation, or can the present invention learns by putting into practice.Purpose of the present invention and other advantage will realize and acquisition with specifically noted structure in written explanation and sharp claim of totalitarity and the accompanying drawing.
In order to reach purpose of the present invention, comprise according to the fiber amplifier of a first aspect of the present invention: by the optical link of its transmitting optical signal; Be arranged on rare-earth doped optical fibre on this optical link, that be doped with predetermined rare earth ion; Be used to generate the pumping electron gun of pump beam with predetermined wavelength; Be used for pump beam is coupled to first multiplexer on the optical link; Be used for second multiplexer of beam split by the pump beam of rare-earth doped optical fibre output; And use the pump beam feedback device that the pump beam of a part of beam split is circulated back to rare-earth doped optical fibre.
Another fiber amplifier according to a first aspect of the present invention comprises: by first optical link of its transmitting optical signal; Be arranged on rare-earth doped optical fibre on the optical link, that be doped with predetermined rare earth ion; Be used to generate the first pumping electron gun of first pump beam with predetermined wavelength; Be used to generate the second pump light electron gun of second pump beam with predetermined wavelength; Be used for first pump beam is coupled to by first multiplexer on the light signal of optical link transmission, first pump beam and light signal transmit on same direction; Be used for second pump beam is coupled to by second multiplexer on the light signal of optical link transmission, second pump beam is to transmit on the opposite direction of light signal; Be used for three multiplexer of beam split by output of rear-earth-doped optical fiber and the pump beam on the same direction of light signal, transmitted; Be used for four multiplexer of beam split by rare-earth doped optical fibre output and the pump beam on the opposite direction of light signal, transmitted; And be optically coupled in second optical link on the 3rd and the 4th multiplexer, wherein the 3rd and the 4th multiplexer is by the pump beam of second optical link output beam split, and will be coupled to by the pump beam that optical link receives on first optical link.
Another fiber amplifier according to a first aspect of the present invention also comprises the feedback pump beam checkout gear that is used to detect the pump beam amount that is looped back by feedback control loop, and the control device that is used for the output energy level of first and second pumping electron gun of control on the basis of the detected pump beam amount of feedback pump beam checkout gear.
In order to reach purpose of the present invention, comprise according to the fiber amplifier of a second aspect of the present invention: by the optical link of its transmitting optical signal; Be arranged on rare-earth doped optical fibre on the optical link, that be doped with predetermined rare earth ion; Be used to generate the pumping electron gun of pump beam with predetermined wavelength; Be used for pump beam is coupled to first multiplexer on the optical link; And be used for beam split and offer the pump beam circulating device of rare-earth doped optical fibre again from the pump beam of rare-earth doped optical fibre output and with it.
Another fiber amplifier according to a second aspect of the present invention comprises: by the optical link of its transmitting optical signal; Be arranged on rare-earth doped optical fibre on the optical link, that be doped with predetermined rare earth ion; Be used to generate the first pumping electron gun of first pump beam with predetermined wavelength; Be used to generate the second pumping electron gun of second pump beam with predetermined wavelength; Be used for first pump beam is coupled to by first multiplexer on the light signal of optical link transmission, first pump beam and light signal transmit on equidirectional; Be used for second pump beam is coupled to by second multiplexer on the light signal of optical link transmission, second pump beam is to transmit on the opposite direction of light signal; Be used for beam split and offer the first pump beam circulating device of rare-earth doped optical fibre again by pump beam rare-earth doped optical fibre output and transmission on light signal equidirectional and with it; And be used for beam split, and it is offered the second pump beam circulating device of rare-earth doped optical fibre again by rare-earth doped optical fibre pump beam output and that on the opposite direction of light signal, transmit.
Another fiber amplifier of a second aspect of the present invention comprises that at least one is used for the pump beam checkout gear of the pump beam amount that the detection of reflected loop reflected, and is used for the control device of the output energy level of first and second pumping electron gun of control on the basis of the detected pump beam amount of pump beam checkout gear.
According to the present invention who as above constitutes, to be coupled on feedback loop or the reflex circuit from the residual pump beam of rare-earth doped optical fibre output by multiplexer, and the residual pump beam that feedback loop or reflex circuit loop back is offered rare-earth doped optical fibre again with multiplexer.Thereby, compare with traditional situation, might shorten the length of rare-earth doped optical fibre significantly, and prevent from optical fiber is passed through in the pump beam transmission.Moreover, because control device is in the output of the basis of the pilot signal that provides from feedback pump beam feedback device control pumping electron gun, also might be in optimum state with the amplification control from view of profit of fiber amplifier.
The generality description that should understand above all is exemplary and illustrative with following detailed, and aims to provide desired of the present invention further specifying.
For providing further understanding of the present invention is comprised and adds and the accompanying drawing that constitutes the part of this specification is showed embodiments of the invention, and be used for illustrating principle of the present invention with explanation.In the accompanying drawing:
Fig. 1 illustrates the configuration of traditional fiber amplifier;
Fig. 2 illustrates the configuration that comprises according to the fiber amplifier of the pump beam feedback loop of first embodiment of a first aspect of the present invention;
Fig. 3 illustrates the configuration that comprises according to the fiber amplifier of the pump beam feedback loop of second embodiment of a first aspect of the present invention;
Fig. 4 illustrates the configuration that comprises according to the fiber amplifier of the pump beam feedback loop of the 3rd embodiment of a first aspect of the present invention;
Fig. 5 and Fig. 6 illustrate the configuration that comprises according to the fiber amplifier of the pump beam feedback loop of other embodiments of the invention;
Fig. 7 illustrates the configuration that comprises according to the fiber amplifier of the reflection loop of first embodiment of a second aspect of the present invention;
Fig. 8 illustrates the configuration that comprises according to the fiber amplifier of the reflection loop of second embodiment of a second aspect of the present invention; And
Fig. 9 illustrates the configuration that comprises according to the fiber amplifier of the reflection loop of the 3rd embodiment of a second aspect of the present invention.
In detail referring to the embodiment that ties of the present invention, the example illustrates in the accompanying drawings now.
Fig. 2 illustrates the configuration that comprises according to the fiber amplifier of the pump beam feedback control loop of first embodiment of a first aspect of the present invention, and its adopts the circulating device of feedback control loop as pump beam.Referring to Fig. 2, input optical signal S is coupling on first optical link 21, and the pump beam P that pump diode 22 generates then is coupling on second optical link 23.First and second optical link 21 and 23 is offered first wavelength division multiplexer 24 as its input.Here, light signal S has the wavelength such as 1520nm to 1570nm, and pump beam P then has the wavelength of 980nm or 1480nm.The power output of pump diode 22 is determined by the operating current that provides from control circuit 42.
First multiplexer, 24 coupling optical signal S and pump beam P, and they are delivered to second wavelength division multiplexer 26 by the 3rd optical link 25 on the input that is coupling in second multiplexer 26.Second wavelength division multiplexer 26 is coupled the feedback pump beam P of light signal S and pump beam P and following the 8th optical link 34 receptions that will illustrate, and by the 4th optical link 27 that is connected as its input on the rear-earth-doped optical fiber 28 they is delivered to rare-earth doped optical fibre 28.Optical fiber 28 is doped with such as rare earth ions such as Er, and its length setting is such as the rare-earth doped optical fibre in the traditional fiber amplifier half.Optical fiber 28 is not fixed on the particular length but depends on wavelength or the power of the pump beam P that pump diode 22 generates.
To be coupling in from the output beam of rare-earth doped optical fibre 28 on the 5th optical link 29 that is connected to the 3rd wavelength division multiplexer 30.Here, owing to compare with traditional fiber, rare-earth doped optical fibre 28 is to have shortened significantly, if the power of the pump beam P that pump diode 22 generates is similar in the traditional fiber amplifier, then pump beam P will remain on the 5th optical link 29 together with light signal S.The 3rd multiplexer 30 beam split light signal S and pump beam on the basis of their wavelength, and they are coupled to respectively on the 6th and the 7th optical link 31 and 32.
To be coupled on the 8th optical link 34 by the pump beam P that the 7th optical link 32 is propagated by first tap coupler 33, the 8th optical link 34 is connected on another input of second multiplexer 26.Here, the 7th and the 8th optical link 32 and 34 is the feedback control loop of residual pump beam formation from rare-earth doped optical fibre 28 outputs.First tap coupler 33 is by the pump beam P that applies from the 7th optical link 32 such as 99: 1 predetermined ratio beam split, and each branch of pump beam is coupled to respectively on the 8th optical link 34 and the 9th optical link 35.The pump beam of first photodiode, 36 opto-electronic conversion by the effect of the 9th optical link 35 is to offer control circuit 42 as pilot signal.
To be coupling on second tap coupler 38 by the isolator 37 that blocks reflected light signal by the light signal S that the 3rd multiplexer 30 is coupling on the 6th optical link 31.Second tap coupler 38 is pressed such as 99: 1 predetermined ratio beam split light signal S such as grade, and each branch is coupled to respectively on the tenth and the 11 optical link 39 and 40.The light signal S part that is coupled on the tenth optical link 39 is transmitted as output signal, and the light signal S part that is coupled on the 11 optical link 40 then acts on the control circuit 42 by second photodiode, 41 opto-electronic conversion and as pilot signal.
Control circuit 42 is supplied to the operating current amount of pump diode 22 according to the pilot signal control by first and second photodiode 36 and 41 effects.This is, when being high at the level from the pilot signal of first photodiode 36, control circuit 42 by reducing the operating current of supplying with pump diode 22, and by increasing the operating current amount fiber amplifier is being controlled in the optimum state when low from the level of the pilot signal of second photodiode 41.
In the fiber amplifier that as above constitutes, the pump beam P that first multiplexer 24 will generate by the light signal S and the pump diode 22 of first optical link, 21 inputs is coupled mutually, for passing through tertiary circuit 25 outputs.By second multiplexer 26 with light signal S and pump beam P be fed the pump beam coupling that loop 34 loops back, to act on the rare-earth doped optical fibre 28.The rare earth ion that pump beam P excitation mixes in the optical fiber 28 is subjected to pumping with what generation had a predetermined wavelength, and they are incorporated among the light signal S that will amplify.The light signal S that will amplify in rare-earth doped optical fibre 28 is coupled on the 6th optical link 31 by the 3rd multiplexer 30, and its loss is very little, for transmitting by isolator 37.
In this case, owing to compare with traditional situation, the length setting of optical fiber 28 must be shorter, pump beam P is retained in the output beam from rare-earth doped optical fibre 28, and residual pump beam is by 30 wavelength-divisions of the 3rd multiplexer and by being coupled on second multiplexer 26 by the 7th and the 8th optical link 32 and 34 feedback control loops that constitute.Second multiplexer 26 will be fed the residual pump beam P that looped cycle returns and be coupled on the 4th optical link 27, so that pump beam P is offered rare-earth doped optical fibre 28 again.
This is, in the configuration of above-mentioned fiber amplifier, the pump beam P that pump diode 22 generates passes through rare-earth doped optical fibre at least by feedback control loop 32 and 34 28 twice.Thereby, compare with conventional situation, can shorten the length of rare-earth doped optical fibre 28 significantly.Moreover owing to be coupling on feedback control loop 32 and 34 by the 3rd multiplexer 30 from the residual pump beam P of rare-earth doped optical fibre 28 outputs, just independently speculum prevents that pump beam P from propagating by optical link.Moreover control circuit 42 is according to the output of controlling pump diode 22 from the pilot signal of first and second photodiode 36 and 41 effects.Thereby, can be in optimum state with the amplification control from view of profit of fiber amplifier.
Fig. 3 illustrates the configuration according to the fiber amplifier of second embodiment of a first aspect of the present invention, opposite with the direction incentive mode that pump beam P and light signal S are provided on same direction among first embodiment, second embodiment adopts incentive mode in the other direction, and wherein pump beam P provides on the opposite direction of light signal S.Referring to Fig. 3, input optical signal S is coupling on first optical link 51, and an input is coupling on first wavelength division multiplexer 52 latter as one again.First multiplexer 52 is coupled to light signal S on second optical link 53, and will be coupled to by the residual pump beam P that second optical link 53 applies from rare-earth doped optical fibre 54 on the 3rd optical link 55.
The pump beam P that is coupling on the 3rd optical link 55 is coupled on first tap coupler 56, and the latter is with such as 99: 1 predetermined score optical pumping bundle P, and each branch is coupled to respectively on the 4th and the 5th optical link 57 and 58.The 4th optical link 57 is connected on second multiplexer 61 as its input, and is that residual pump beam P from optical fiber 54 output constitutes feedback control loop with the 3rd optical link 55.The partial action that will be coupling in the pump beam P on the 5th circuit with first tap coupler 56 opto-electronic conversion in addition on first photodiode 59, and offer control circuit 72 as pilot signal.
Deliver to its output beam and act on rare-earth doped optical fibre 54 on second multiplexer 61 being coupling in light signal S on second circuit 53 by the 6th optical link 60.Second multiplexer 61 will be coupled on the 7th optical link 62 by the light signal S that the 6th circuit 60 receives, and will be coupled in the input of rare-earth doped optical fibre 54 by the 6th optical link 60 by the pump beam that reaches from feedback control loop 55 and 57 of the 7th optical link 62 effects.
In second embodiment of this a first aspect of the present invention, the light beam that for example will have a wavelength 1520 to 1570nm is as light signal S, and the light beam that will have wavelength 980 or a 1460nm is as pump beam P.Optical fiber 54 is doped with such as rare earth ions such as Er ions, and its length setting is half length of optical fiber used in the traditional fiber amplifier.Among Fig. 3, reference number 63 is illustrated in the following pump diode that generates the pump beam with presetted wavelength of control of control circuit 72.To be coupled on the 8th optical link 64 from the pump beam P that pump diode 63 generates, the latter is connected on the 3rd multiplexer 65 as its input.The 3rd multiplexer 65 will be coupled on the 9th optical link 66 by the light signal S that the 7th optical link 62 receives, and on mutual the 7th optical link 62 that will be coupled from the pump beam P of the 8th optical link 64 effects.
To be coupling on second tap coupler 68 by the isolator 67 that blocks reflected light signal by the light signal S that the 9th optical link 66 is propagated.Second tap coupler 68 predetermined with such as 99: 1 than beam split light signal S, and respectively each branch is coupling on the tenth and the 11 optical link 69 and 70.The light signal S that is coupled on the tenth optical link 69 partly transmits as output signal, and the light signal part that is coupled on the 11 optical link 70 is then passed through second photodiode, 71 opto-electronic conversion, and offers control circuit 72 as pilot signal.
In fiber amplifier according to second embodiment of a first aspect of the present invention, the pump beam P that pump diode 63 is generated delivers to rare-earth doped optical fibre 54 by the 3rd and second multiplexer 65 and 61, and excitation is entrained in the rare earth ion in the optical fiber 54, be subjected to pumping with what generation had a predetermined wavelength, and they are incorporated into by among input of first multiplexer 52 and the light signal S by optical fiber 54 transmission, with amplifying optical signals S.
Moreover, owing to compare with traditional situation, shortened the length of rare-earth doped optical fibre 54 significantly, pump beam from optical fiber 54 output scheduled volumes, and residual pump beam is acted on feedback control loop 55 and 57 by first multiplexer 52, be fed looped cycle and return, and be coupled on the 6th optical link 60, for offering rare-earth doped optical fibre 54 again by second multiplexer 61.Control circuit 72 is according to the output of controlling pump diode 63 from the pilot signal of first and second photodiode 59 and 71.Thereby the electrical power efficiency of fiber amplifier is optimized and rare-earth doped optical fibre 54 is shortened.Moreover, be provided to again wherein continuously by feedback control loop 55 and 57 from the pump beam P of rare-earth doped optical fibre 54 output, might prevent that just pump beam from transmitting by optical link.
Fig. 4 illustrates the configuration that comprises according to the fiber amplifier of the reflection loop of the 3rd embodiment of a first aspect of the present invention, and this amplifier adopts two-way incentive mode.Referring to Fig. 4, the first pump beam P1 that input optical signal S and pump diode 81 generate is coupled mutually with first wavelength division multiplexer 82,, acts on then on the rare-earth doped optical fibre 84 by second wavelength division multiplexer 83 with minimum loss.The length of optical fiber 84 is equivalent to half the length of rare-earth doped optical fibre of traditional fiber amplifier.Pass through the 3rd and the 4th wavelength multiplexer 85 and 86 from the light signal S of rare-earth doped optical fibre 84 outputs, lose minimum.
From the residual first pump beam P1 of rare-earth doped optical fibre 84 output by 85 wavelength-divisions of the 3rd multiplexer and be coupled on the feedback control loop 87.The first pump beam P1 is circulated back to second multiplexer 83 by feedback control loop 87, so that offer rare-earth doped optical fibre 84 again.The second pump beam P2 that second pump diode 88 is generated is coupled on the input of the 4th multiplexer 86, so that offer rare-earth doped optical fibre 84 by the 3rd multiplexer 85.From the residual second pump beam P2 of optical fiber 84 output by 83 wavelength-divisions of second multiplexer, so that be coupled on the feedback control loop 87.Then, the residual second pump beam P2 that feedback control loop 87 is circulated back to the 3rd multiplexer 85 offers optical fiber 84 again.
Feedback control loop 87 comprises with first or second pump beam P1 that will provide from feedback control loop 87 such as 99: 1 predetermined ratio or first tap coupler 89 of P2 beam split, and the pump beam of a part of beam split acted on first photodiode 90, the pump beam that latter's opto-electronic conversion receives also offers control circuit 94 with it as pilot signal.To be coupling on second tap coupler 92 from the light signal S of the 4th multiplexer 86 outputs by the isolator 91 that blocks reflected light signal.Second tap coupler 92 is from the predetermined light signal S that exports from isolator 91 than beam split such as 99: 1, and the light signal of a part of beam split acted on second photodiode 93, the light signal that latter's opto-electronic conversion is received also offers control circuit 94 with it as pilot signal.
Control circuit 94 is provided according to the pilot signal control that provides by first and second photodiode 90 and 93 by the operating current amount of first and second pump diode 81 and 88.This is, when the level of the pilot signal that provides from first photodiode 90 when being high by reducing first and second pump light diode 81 and 88 the operating current amount supplied with, and when by increase operating current amount fiber amplifier being controlled at the optimum state when hanging down from the level of the pilot signal that provides with boundary photodiode 93.
As mentioned above, light signal S acts on the rare-earth doped optical fibre 84 by first and second multiplexer 82 and 83.Here, pumping signal as rare-earth doped optical fibre 84, offer it by first and second multiplexer 82 and the 83 first pump beam P1 that first pump diode 81 is generated, and also offer it by the 4th and the 3rd multiplexer 86 and the 85 second pump beam P2 that second pump diode 88 is generated.First and second pump beam P1 has identical wavelength with P2.
With the length setting of rare-earth doped optical fibre 84 is to be shorter than traditional optical fiber.Thereby, when first and second pump light diode 81 and 88 output and traditional fiber amplifier the same big, not full consumption and remaining in the rare-earth doped optical fibre 84 of first and second pump beam P1 and P2.The residual light beam of first and second pump beam P1 and P2 is respectively by the 3rd and second multiplexer 85 and 83 wavelength-divisions, so that be coupled on the feedback control loop 87.With feedback control loop 87 they are circulated back to the 3rd and second multiplexer 85 and 83 then, so that act on the rare-earth doped optical fibre 84.Do not exhaust and left in rare-earth doped optical fibre 84 time in pump beam, this feedback operation of first and second pump beam P1 and P2 continues to carry out.
When first and second pump beam P1 and P2 are offered rare-earth doped optical fibre 84, be subjected to pumping so that just introduce among the light signal S of optical fiber 94 transmission to amplify this light signal from optical fiber 94 emissions.Control circuit 94 according to the output of controlling first and second pump diode 81 and 90 from first and second photodiode 90 and the pilot signals of 93 supplies with the amplification control from view of profit of fiber amplifier optimum state.
In the 3rd embodiment of a first aspect of the present invention, be fed loop 87 from the pump beam of rare-earth doped optical fibre 84 output and be circulated back to wherein.Thereby, if the same big in first and second pump diode 81 and 88 output and the traditional fiber amplifier, just could be below half of the fiber lengths of traditional fiber amplifier with the contraction in length of rare-earth doped optical fibre 84.Moreover, for pump beam is run out, will be provided to wherein again continuously from the residual pump beam P1 and the P2 of rare-earth doped optical fibre 84 outputs.Here, because first photodiode 90 detects the pump beam amount that offers optical fiber 84 again, and, just the electrical power of fiber amplifier might be set in the optimum state according to the power output of detected first and second pump diode of signal controlling.
Though the present invention is applicable to direction incentive mode and the reverse energization pattern that adopts the single pump diode (pumping source) among the embodiment shown in Fig. 2 and 3, but the present invention also can be applied on the fiber amplifier with a plurality of pumping sources, as shown in Fig. 5 and 6 in the same manner.
Fig. 7 illustrates the configuration according to the fiber amplifier of first embodiment of a second aspect of the present invention, and it adopts the circulating device of reflection loop as pump beam.Referring to Fig. 7, input optical signal S is coupling on first optical link 121, and the pump beam P that pump diode 122 is generated is coupling on second optical link 123.First and second optical link 121 and 123 is offered first wavelength division multiplexer 124 as its input.Here, light signal S has the wavelength such as 1520 to 1570nm, and pump beam P then has the wavelength of 980nm or 1480nm.The power output of pump diode 122 is to be determined by the operating current that control circuit 140 provides.
To be coupling on second tap coupler 136 by the isolator 135 that blocks reflected light signal by the light signal S that second multiplexer 128 is coupling on the 5th optical link 129.Second tap coupler 136 predetermined with such as 99: 1 than beam split light signal S, and each branch is coupled to respectively on the 8th and the 9th optical link 137 and 138.The part that is coupled to the light signal S on the 8th optical link 137 is transmitted as output signal, the part that is coupled to the light signal S on the 9th optical link 138 is then by second photodiode, 139 opto-electronic conversion, so that act on the control circuit 140 as pilot signal.
In the fiber amplifier that as above constitutes, first multiplexer 124 is coupled the pump beam of input optical signal S and pump diode 122 generations mutually, and they are acted on the rare-earth doped optical fibre 126, the rare earth ion that pump beam P excitation therein is entrained in wherein is subjected to pumping with what generation had a predetermined wavelength.To be subjected to pumping son to introduce among the light signal S and amplify it.Here, owing to compare with traditional situation, the length setting of rare-earth doped optical fibre 126 must be shorter, and pump beam P remains in from the output beam of optical fiber 126.By second multiplexer 128 residual pump beam is coupled on the reflection loop 132, and the looped cycle that is reflected is returned so that be coupled to again on second multiplexer 128 by tap coupler 131.Second multiplexer 128 sends to pump beam P on the rare-earth doped optical fibre by the 4th optical link 127.
In above-mentioned fiber amplifier, the pump beam P that pump diode 122 generates is by rare-earth doped optical fibre 126 at least twice.Thereby, compare with the optical fiber in the traditional fiber amplifier, can shorten the length of optical fiber 126 significantly.Moreover the residual pump beam of exporting from rare-earth doped optical fibre 126 is coupled on the reflection loop 132 by second multiplexer 128, and the looped cycle that is reflected is returned, and acts on again on the rare-earth doped optical fibre 126 by second multiplexer 128.Thereby might need not setting up independently, speculum just prevents pump beam P transmission passing through optical fiber.Moreover control circuit 140 is by according to the output of controlling the pump diode 122 of generation pump beam P from first and second photodiode 134 and the pilot signals of 130 effects, and the amplification rate of putting that optical fiber is gone into big device is controlled in the optimum state.
Fig. 8 illustrates the configuration that has according to the fiber amplifier of the pump beam reflection loop of second embodiment of a second aspect of the present invention, it adopts the reverse energization pattern, opposite with the direction incentive mode of first embodiment that pump beam P and light signal S are provided on same direction therein, pump beam P provides on the opposite direction of light signal S in a second embodiment.Referring to Fig. 8, input optical signal S to be coupled on first optical link 141, the latter is connected on first wavelength division multiplexer 142 as its input.First multiplexer 142 will be coupled on the 3rd optical link 144 by second optical link, 143 effect pump beam P thereon, and will be coupled on the light signal S that acts on by first optical link 141, by the pump beam P of the 3rd optical link 44 effects so that they are delivered on second optical link 143.
To be coupled on the reflection loop 146 by first tap coupler 145 by the pump beam P that first multiplexer 142 is coupling on the 3rd optical link 144, its loss is few, is looped back by the reflection loop, so that be coupled to again on first tap coupler 145.First tap coupler 145 predetermined with such as 99: 1 than the beam split pump beam P that loop 146 loops back that is reflected, and each branch is coupled to respectively on the 3rd and the 4th optical link 144 and 147.The pump beam P part that is coupling on the 3rd optical link 144 is acted on first multiplexer 142 again as its input.Thereby, be coupled to by first multiplexer 142 and comprise in the light beam on second optical link 143 by the light signal S of first optical link, 141 inputs and the pump beam that loops back by reflection loop 146.To partly be delivered to first photodiode 148 by the pump beam P that first tap coupler 145 is coupling on the 4th optical link 147, opto-electronic conversion acts on the control circuit 160 as pilot signal then in addition.Act on the rare-earth doped optical fibre 149 being coupling in the light signal S on second optical link 143 and the pump beam P of reflection, the latter's output beam is coupling on second wavelength division multiplexer 151 as its input by the 5th optical link 150.
In second embodiment of this a second aspect of the present invention, adopted such as light beam as light signal, and employing has the light beam of wavelength 980 or 1480nm as pump beam P with wavelength 1520 to 1570nm.Optical fiber 149 is doped with such as rare earth ions such as Er, and is half of fiber lengths in the traditional fiber amplifier with its length setting.Among Fig. 8, reference number 152 is illustrated in the following pump diode that generates the pump beam P with predetermined wavelength of control of control circuit 160.The pump beam P that pump diode 152 is generated is coupled on the 6th optical link 153, and the latter is connected on second multiplexer 151 as its input.Second multiplexer 151 will be coupling on the 5th optical link 150 by the pump beam P that the 6th optical link 153 receives, so that it is offered rare-earth doped optical fibre 149 as exciting light beam.
To be coupled to from the light signal S of second multiplexer 151 on the 7th circuit 154, the latter is connected on second tap coupler 156 by the isolator 155 that blocks reflected light signal.Second coupler 156 predetermined with such as 99: 1 than beam split light signal S, and each branch is coupled to respectively on the 8th and the 9th optical link 157 and 158.The light signal that is coupling on the 8th optical link 157 partly transmits as output signal, be coupling in light signal part on the 9th optical link 158 then by second photodiode 159 opto-electronic conversion in addition, so that offer control circuit 160 as pilot signal.
Control circuit 160, similar with first embodiment, in the following manner according to the operating current amount of supplying with pump diode 152 by the pilot signal control of first and second photodiode 148 and 159 effects, promptly when the level of the pilot signal of first photodiode 148 effect when being high, reduce the operating current amount, and when the level of the pilot signal of second photodiode 159 effect when low, increase the operating current amount, whereby fiber amplifier is controlled in the optimum state.
In according to the fiber amplifier among second embodiment of a second aspect of the present invention, the pump beam P that pump diode 152 is generated delivers to rare-earth doped optical fibre 149 by second multiplexer 151, and the rare earth ion that excitation is doped to wherein is subjected to pumping with what generation had a predetermined wavelength, and they are incorporated into by the input of first multiplexer 142 and among the light signal S by optical fiber 54 transmission, thereby amplifying optical signals S.
Moreover, owing to compare, having shortened the length of rare-earth doped optical fibre 149 significantly with traditional situation, a part of pump beam P just remains in the output beam from rare-earth doped optical fibre 149.And residual pump beam is delivered to reflection loop 146 by first multiplexer 142.The residual pump beam P that reflection loop 146 is looped back is coupled on first multiplexer 142 by tap coupler 145, first multiplexer then offers rare-earth doped optical fibre 149 with the circulation pump beam, it is coupled on second optical link 143 again.Control circuit 160 is according to the output of controlling pump diode 152 from the pilot signal of first and second photodiode 148 and 159.Thereby the electrical power efficiency of fiber amplifier is optimized, and the length of rare-earth doped optical fibre 149 is shortened simultaneously.
Fig. 9 illustrates the configuration that comprises according to the fiber amplifier of the pump beam reflection loop of the 3rd embodiment of a second aspect of the present invention, and it has adopted two-way incentive mode.Referring to Fig. 9, first wavelength division multiplexer 172 is coupled first pump beam of input optical signal S and 171 generations of first pump diode,, acts on then on the rare-earth doped optical fibre 174 by second wavelength division multiplexer 173 with few loss.The length setting of optical fiber 174 is half of fiber lengths in the traditional fiber amplifier.Pass through the 3rd and the 4th wavelength division multiplexer 175 and 176 from the light signal S of rare-earth doped optical fibre 174 outputs with minimum loss.
Be coupling on the first reflection loop 178 by 175 wavelength-divisions of the 3rd multiplexer and by first tap coupler 177 from the residual first pump beam P1 of rare-earth doped optical fibre 174 outputs.The residual first pump beam P1 that the first reflection loop 178 is looped back is coupled on the 3rd multiplexer 175 so that offer rare-earth doped optical fibre 174 again by first tap coupler 177.First tap coupler 177 is with such as 99: 1 the predetermined first pump beam P1 that loops back than the beam split first reflection loop 178, and the part of first pump beam of beam split is acted on first photodiode 179.This part first pump beam P1 is by first photodiode, 179 opto-electronic conversion, so that act on the control circuit 187 as pilot signal.
The second pump beam P2 that second pump diode 180 is generated is coupled in the input of the 4th multiplexer 176, so that offer rare-earth doped optical fibre 174 by the 3rd multiplexer 175.Be coupled to the second reflection loop 182 from the residual second pump beam P2 of rare-earth doped optical fibre 174 outputs by 173 wavelength-divisions of second multiplexer and by second tap coupler 181.Then, the second reflection loop 182 loops back the residual second pump beam P2 and be coupled to by second tap coupler 181 in the input of second multiplexer 173 as its input, so that offer rare-earth doped optical fibre 174.
The operating current amount that offers first and second pump diode 171 and 180 is provided according to the pilot signal that provides by first, second and the 3rd photodiode 179,183 and 186 for control circuit 187.This is, the operating current amount of supplying with first or second pump diode 171 and 180 is provided when being high at the level from first or second photodiode 179 of correspondence or 180 pilot signals that provide control circuit 187, and increase the operating current amount when low at the level of the pilot signal that provides from the 3rd photodiode 186, and fiber amplifier is controlled in the optimum state.
As mentioned above, by first and second multiplexer 172 and 173 light signal S is acted on the rare-earth doped optical fibre 174.Here, pumping signal as rare-earth doped optical fibre 174, offer rare-earth doped optical fibre 174 by first and second multiplexer 172 and the 173 first pump beam P1 that first pump diode 171 is generated, and also offer rare-earth doped optical fibre 174 by the 4th and the 3rd multiplexer 176 and the 175 second pump beam P2 that second pump diode 180 is generated.Here, first and second pump beam P1 has identical wavelength with P2.
With the length setting of rare-earth doped optical fibre 174 is to be shorter than the traditional fiber amplifier.Thereby,, do not exhaust first and second pump beam P1 and P2 but remain in the rare-earth doped optical fibre 174 when the output of the output of first and second pump diode 171 and 180 and traditional fiber amplifier as many time.The residual light beam of first and second pump beam is respectively by the 3rd and second multiplexer 175 and 173 wavelength-divisions, so that be coupled on first and second reflection loop 178 and 182.Then, residual pump beam P1 and the P2 that reflection loop 178 and 182 is looped back acts on the rare-earth doped optical fibre 174 again by the 3rd and second multiplexer 175 and 173.When pump beam does not exhaust and remains in the rare-earth doped optical fibre 174, continue as first and second pump beam P1 and P2 and carry out this reflective operation.
When first and second pump beam P1 and P2 are offered rare-earth doped optical fibre 174, just be subjected to pumping from rare-earth doped optical fibre 174 emissions, amplified by the light signal S of its transmission so that introduce.Control circuit 187 by the output that first and second pump diode 171 and 180 are provided according to the pilot signal that provides from first, second and the 3rd optical diode 179,183 and 186 with the amplification control from view of profit of fiber amplifier optimum state.
In the 3rd embodiment, pass through reflection loop reflected back wherein from the pump beam of rare-earth doped optical fibre 174 outputs, and repeatedly carry out this reflection by first and second reflection loop 178 and 182.Thereby, can be below half with the contraction in length of optical fiber 174 fiber lengths in traditional fiber amplifier.Moreover, in order to exhaust pump beam, will be provided to wherein again from the residual pump beam of rare-earth doped optical fibre 174 outputs continuously.Here, first and second photodiode 179 and 183 detects the amount of the pump beam that offers optical fiber 174 again, and according to the power output of first and second pump diode 171 of detected signal controlling and 180, the power efficiency with fiber amplifier is set in the optimum state whereby.
As mentioned above, according to the present invention, shortened the length that is used in the rare-earth doped optical fibre in the fiber amplifier significantly.Moreover, in rare-earth doped optical fibre, exhaust pump beam, improving the amplification efficient of fiber amplifier, and prevent that residual pump beam transmission from passing through optical link.
For person skilled in the art person, obviously can in fiber amplifier of the present invention, make various corrections and modification and do not break away from spirit of the present invention and scope.Thereby as long as they enter within the scope of appended claims and equivalent thereof, the present invention is intended to cover the correction and the modification of this invention.
Claims (19)
1. fiber amplifier comprises:
Optical link by its transmitting optical signal;
Be arranged on the rare-earth doped optical fibre that is doped with predetermined rare earth ion on the optical link;
Be used to generate the pumping electron gun of pump beam with predetermined wavelength;
Be used for pump beam is coupled to first multiplexer on the optical link;
Be used for second multiplexer of beam split by the pump beam of rare-earth doped optical fibre output; And
The pump beam of a part of beam split of being used to circulate is got back to the pump beam feedback device of rare-earth doped optical fibre.
2. desired fiber amplifier in the claim 1 wherein is coupling in pump beam and the equidirectional transmission of light signal on the optical link with first multiplexer.
3. desired fiber amplifier in the claim 1, wherein the pump beam that is coupling on the optical link with first multiplexer is transmitted in the other direction with light signal.
4. desired fiber amplifier in the claim 1 also comprises:
The pump beam checkout gear is used to detect the pump beam amount that is circulated back to rare-earth doped optical fibre by feedback device; And
Control device is used for the output energy level according to the detected pump beam amount control of pump beam checkout gear pumping electron gun.
5. desired fiber amplifier in the claim 1 also comprises:
The optical signal detecting device is used to detect the light signal amount of amplifying by rare-earth doped optical fibre; And
Control device is used for the output energy level according to the detected light signal amount control of optical signal detecting device pumping electron gun.
6. fiber amplifier that comprises the pump beam feedback control loop comprises:
First optical link by its transmitting optical signal;
Be arranged on the rare-earth doped optical fibre that is doped with predetermined rare earth ion on the optical link;
Be used to generate the first pumping electron gun of first pump beam with predetermined wavelength;
Be used to generate the second pumping electron gun of second pump beam with predetermined wavelength;
Be used for first pump beam is coupled to by first multiplexer on the light signal of optical link transmission, first pump beam and light signal are equidirectional transmission;
Be used for second pump beam is coupled to by second multiplexer on the light signal of optical link transmission, second pump beam and light signal are transmission in the other direction;
Be used for beam split by rare-earth doped optical fibre output and with the 3rd multiplexer of the pump beam of the equidirectional transmission of light signal;
The 4th multiplexer that is used for the pump beam that beam split transmits by rare-earth doped optical fibre output and with light signal in the other direction; And
Be optically coupled in second optical link on the 3rd and the 4th multiplexer,
Wherein the 3rd and the 4th multiplexer is exported the pump beam of beam split by second optical link, and will be coupled to by the pump beam that optical link receives on first optical link.
7. desired fiber amplifier in the claim 6 also comprises:
The pump beam checkout gear is used to detect the pump beam amount by the transmission of second optical link; And
Control device is used for controlling according to the detected pump beam amount of pump beam checkout gear the output energy level of first and second pumping electron gun.
8. desired fiber amplifier in the claim 6 also comprises:
The optical signal detecting device is used to detect the light signal amount of amplifying by rare-earth doped optical fibre; And
Control device is used for controlling according to the detected light signal amount of optical signal detecting device the output energy level of first and second pumping electron gun.
9. fiber amplifier that comprises the pump beam feedback device comprises:
Optical link by its transmitting optical signal;
Be arranged on the rare-earth doped optical fibre that is doped with predetermined rare earth ion on the optical link;
A plurality of pumping electron guns, each generation has the pump beam of predetermined wavelength;
Be used for pump beam is coupled to a plurality of light beam coupling multiplexers on the optical link;
Be used for a plurality of light beams of beam split by the pump beam of rare-earth doped optical fibre output and divide optical multiplexer; And
Be used for the pump beam feedback device that will be divided the pump beam of optical multiplexer beam split to be circulated back to rare-earth doped optical fibre by light beam.
10. one kind comprises the fiber amplifier that pump beam reflects loop, comprising:
Optical link by its transmitting optical signal;
Be arranged on the rare-earth doped optical fibre that is doped with predetermined rare earth ion on the optical link;
Be used to generate the pumping electron gun of pump beam with predetermined wavelength;
Be used for pump beam is coupled to first multiplexer on the optical link; And
Be used for beam split and offer the pump beam circulating device of rare-earth doped optical fibre again from the pump beam of rare-earth doped optical fibre output and with it.
11. desired fiber amplifier in the claim 10, wherein this pump beam circulating device comprises second multiplexer that is connected on the optical link, and be used to reflect circulation and be coupled on second multiplexer reflection loop as its input from the light beam of second multiplexer output and with it, second multiplexer will act on the reflection loop in the pump beam by optical link transmission on the first direction, and will be coupled to from the pump beam that the reflection loop receives with the first direction rightabout on optical link on.
12. desired fiber amplifier in the claim 10, wherein the pump beam that is coupling on the optical link with first multiplexer is transmitted on light signal is equidirectional.
13. desired fiber amplifier in the claim 10, wherein the pump beam that is coupling on the optical link with first multiplexer is transmitted in the other direction at light signal.
14. desired fiber amplifier in the claim 10 also comprises:
The pump beam checkout gear is used to detect the pump beam amount that is looped back by the pump beam circulating device; And
Control device is used for the output energy level according to the detected pump beam amount control of pump beam checkout gear pumping electron gun.
15. desired fiber amplifier in the claim 10 also comprises:
The optical signal detecting device is used to detect the light signal amount of amplifying by rare-earth doped optical fibre; And
Control device is used for the output energy level according to the detected light signal amount control of optical detection device pumping electron gun.
16. a fiber amplifier that comprises pump beam reflection loop comprises:
Optical link by its transmitting optical signal;
Be arranged on the rare-earth doped optical fibre that is doped with predetermined rare earth ion on the optical link;
Be used to generate the first pumping electron gun of first pump beam with predetermined wavelength;
Be used to generate the second pumping electron gun of second pump beam with predetermined wavelength;
Be used for first pump beam is coupled to by first multiplexer on the light signal of optical link transmission, first pump beam and light signal are equidirectional transmission;
Be used for second pump beam is coupled to by second multiplexer on the light signal of optical link transmission, second pump beam is transmitted in the other direction with light signal;
Be used for beam split by rare-earth doped optical fibre output and with the pump beam of the equidirectional transmission of light signal, and it is offered the first pump beam circulating device of rare-earth doped optical fibre once again; And
Be used for beam split by rare-earth doped optical fibre output and the pump beam transmitted with light signal in the other direction, and it is offered the second pump beam circulating device of rare-earth doped optical fibre once again.
17. desired fiber amplifier in the claim 16, wherein this pump beam circulating device comprises the multiplexer that is coupling on the optical link, and be used to reflect circulation and be coupled on this multiplexer reflection loop as its input from the light beam of this multiplexer output and with it, this multiplexer will act on this reflection loop in the pump beam by the optical link transmission on the first direction, and this multiplexer will be coupled on the optical link in the direction opposite with light signal from the pump beam that the reflection loop receives.
18. desired fiber amplifier in claim 16 or 17 also comprises:
At least one pump beam checkout gear is used to detect the pump beam amount that is looped back by the pump beam circulating device; And
Control device is used for controlling according to the detected pump beam amount of pump beam bolt side device the output energy level of first and second pump light electron gun.
19. desired fiber amplifier in the claim 16 also comprises:
The optical signal detecting device is used to detect the light signal amount of amplifying by rare-earth doped optical fibre; And
Control device is used for controlling according to the detected light signal amount of this optical signal detecting device the output energy level of first and second pumping electron gun.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN97126139A CN1189724A (en) | 1996-12-31 | 1997-12-31 | Optical fiber amplifier |
Applications Claiming Priority (3)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| KR78527/96 | 1996-12-31 | ||
| KR78489/96 | 1996-12-31 | ||
| CN97126139A CN1189724A (en) | 1996-12-31 | 1997-12-31 | Optical fiber amplifier |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CN1189724A true CN1189724A (en) | 1998-08-05 |
Family
ID=5177561
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN97126139A Pending CN1189724A (en) | 1996-12-31 | 1997-12-31 | Optical fiber amplifier |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN1189724A (en) |
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN101341635B (en) * | 2005-07-07 | 2010-12-22 | 诺基亚西门子通信有限责任两合公司 | Multistage fibre amplifier and method for adapting a pump power of a multistage fibre amplifier |
-
1997
- 1997-12-31 CN CN97126139A patent/CN1189724A/en active Pending
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN101341635B (en) * | 2005-07-07 | 2010-12-22 | 诺基亚西门子通信有限责任两合公司 | Multistage fibre amplifier and method for adapting a pump power of a multistage fibre amplifier |
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