CN2381070Y

CN2381070Y - Cascade erbium-mixed optical-fiber amplified pump light-source switch-in apparatus

Info

Publication number: CN2381070Y
Application number: CN 99216418
Authority: CN
Inventors: 邹美余
Original assignee: Shenzhen Huawei Technologies Co Ltd
Current assignee: Huawei Technologies Co Ltd
Priority date: 1999-07-11
Filing date: 1999-07-11
Publication date: 2000-05-31
Anticipated expiration: 2009-07-11

Abstract

The utility model discloses an access device of a cascade erbium-doped fiber amplifying pumping light source, which comprises at least two pumping light sources. Before a wavelength division multiplexer (WDM) is coupled in an erbium-doped fiber amplifier, the pump light sources are coupled through a coupler in advance, so that the output light of the pumping sources conducts power distribution renewedly at the output end of the coupler, and thus, all the pumping sources form a whole. The power of one of the pumping light sources is regulated, so that the gain of all or multiple sections of erbium-doped fiber is influenced according to fixed proportion, so the harmful effect can not generated or reduced to the flatness of output gain spectral lines, and the gain flatness control difficulty is reduced.

Description

The pump light source access device that the cascade Er-doped fiber amplifies

The utility model relates to the telecommunication field, specifically belongs to the access device of Er-doped fiber amplification pump light source in the optical transmission.

In long-distance optical fiber communication, behind the optical signal transmission certain distance, will add a repeater, the light signal that will weaken amplifies, and continues transmission then.Traditional repeater is earlier low light level conversion of signals to be become the signal of telecommunication, after the signal of telecommunication is carried out shaping and amplifies, converts the electrical signal to the high light signal again and sends.This relay equipment complexity, reliability is not high, to long quite difficult apart from fibres submarine telecommunication.If take image intensifer, directly light signal is amplified, just can save light-electricity-light transfer process, simplify trunking.Erbium-doped fiber amplifier (hereinafter to be referred as EDFA) is exactly a kind of of image intensifer, and it needs pump light source that Er-doped fiber is encouraged, thereby reaches the amplification purpose, concrete structure as shown in Figure 1, flashlight only amplifies through one section Er-doped fiber 203 among this figure.If make powerful EDFA, just must take many pumpings multistage Er-doped fiber to carry out cascade and amplify.When existing high-power EDFA taked the cascade of many pumpings multistage Er-doped fiber to amplify, every section Er-doped fiber used an independently pump light source, and its structure is seen Fig. 2.Fig. 2 only makes the structure of Er-doped fiber amplifier section, and flashlight amplifies through Er-doped fiber 603,703,903,113 behind optical isolator 5 successively, after optical isolator 12 outputs.Before every section Er-doped fiber 603,703,903,113, a wavelength division multiplexer 601,701,901,111 is all arranged respectively, pump laser 602,702,902,112 closes ripple by wavelength division multiplexer 601,701,901,111 and flashlight respectively, export to corresponding Er-doped fiber then, realize amplification flashlight.Also added an optical isolator 8 before wavelength division multiplexer 901, its effect is to prevent reverse bad pump laser of exciting radiation light loss 602,702, also avoids the inverted population of reverse exciting radiation light absorption Er-doped fiber 603,703 simultaneously, reduces gain.

Appearance along with wavelength-division multiplex system, EDFA has been proposed requirements such as flat gain, gain controlling, the gain spectrum of finding EDFA after deliberation has direct relation with the particle inverted population in the Er-doped fiber, and at present for reaching the purpose of gain controlling, mainly realize by changing pumping light power.For single pumping source, just as long as pumping source of control, but when needing a plurality of pumping source, control a pumping and just become problem, because in this cascade structure for high-power output, one of them pump light source of single change, then to wherein one section Er-doped fiber, the particle inverted population change, and other each section does not change, make that the output spectral line that is formed by stacking by each section gain spectrum is uncertain, make quite difficulty of flat gain control.Certainly change four pump light sources simultaneously, but also can bring like this problem in many controls, as should changing which pumping source, each pumping source should change how much power could be under the situation that does not change gain curve ride gain simultaneously.

The purpose of this utility model is the access device that a kind of pump light source is provided for cascade EDFA, when utilizing this device to carry out gain controlling, can not influence the shape of gain curve simultaneously more easily by changing the purpose that less pump light source reaches gain controlling.

The purpose of this utility model is to realize like this, the pump light source access device that the cascade Er-doped fiber amplifies comprises at least two pump lasers, the pump light of its output is before inserting Er-doped fiber, close ripple by wavelength division multiplexer and flashlight, it is characterized in that: the pump light source access device also includes coupler, the pump light of described pump laser output is coupled through coupler earlier, and then exports to wavelength division multiplexer.

Described coupler is 2 * 2 couplers, and its power output ratio is 1: 1; When the hop count of cascade Er-doped fiber is N (N 〉=2), be N as the pump laser number of pumping source, described 2 * 2 coupler numbers are N-1.

Because in the above scheme, pump light source was carried out cross-couplings earlier before inserting Er-doped fiber, make a plurality of pump light sources constitute an integral body, and no longer be independently of one another.The power of regulating one of them pump light source will influence the gain of all or multistage Er-doped fiber by fixed proportion ground, so the flatness that can or reduce the output gain spectral line does not produce harmful effect, when carrying out gain controlling, reduced the difficulty of flat gain control.

The utility model is described in further detail below in conjunction with drawings and Examples.

Fig. 1 is Er-doped fiber amplification principle figure;

Fig. 2 is the pump light source access infrastructure figure that prior art cascade Er-doped fiber amplifies;

Fig. 3 is the pump light source access infrastructure figure of the utility model embodiment.

Fig. 4 is the pump light source access infrastructure figure of another embodiment of the utility model.

The principle that flashlight amplifies through Er-doped fiber as shown in Figure 1, flashlight is by splitter 1, sub-fraction light is told gives detector 401, use as the input signal light detection, most of light enters later the optical isolator 201 of erbium-doped fiber amplifier 2 by splitter 1, pump light with pump light source 205 outputs enters from two ports of wavelength division multiplexer (hereinafter to be referred as WDM) 202 respectively again, the later flashlight port from WDM202 of mixing comes out to insert Er-doped fiber 203 and amplifies, light after amplifying is input to optical branching device 3 through optical isolator 204 again, tell sub-fraction light by splitter 3 and give light detection device 402, export light detection, most of light is exported as flashlight.Wherein optical branching device 1 and optical branching device 3 can be exported to different port by a certain percentage with the flashlight of input, and the effect of optical isolator 201,204 is to prevent reverberation vibration back and forth in light path.

Fig. 2 is the access infrastructure figure of pump light source in the prior art, in front by the agency of.

In the utility model, the pump light source access device that the cascade Er-doped fiber amplifies comprises at least two pump lasers, also includes coupler in addition, and the pump light of pump laser output is coupled through coupler earlier, and then export to wavelength division multiplexer, with photosynthetic wave signal.

An embodiment of the present utility model as shown in Figure 3.It is to be formed by 142,152,172,182 cascades of four sections Er-doped fibers that the Er-doped fiber of present embodiment amplifies, and every section Er-doped fiber all has a WDM.Flashlight closes ripple at the pump light of first WDM141 and pump light source device 21 first output Out1 output behind optical isolator 13, output to first section Er-doped fiber 142 then and carry out the amplification first time.Because of every section Er-doped fiber multiplication factor is limited, so high-power signal is exported, flashlight after once amplifying will be exported to second WDM151, mix with the pump light of pump light source device 21 second output Out2 output, carry out the second time at second section Er-doped fiber 152 then and amplify; Amplify the same with first, second time, flashlight after amplifying for the second time is again successively through the 3rd WDM171, the 3rd section Er-doped fiber 172, the 4th WDM181, the 4th section Er-doped fiber 182, respectively with the pump light mixing amplification of pump light source device 21 the 3rd, the 4th output Out3, Out4 output, export to external circuits through optical isolator 19 then and transmit or make other usefulness.Wherein the effect of isolator 16 also is to prevent reverse exciting radiation influence of light gain amplifier.

According to Fig. 3, present embodiment pump light source device 21 comprises 214,215,216,217 and three 2 * 2 couplers of four pump lasers (LD) 211,212,213.The pump light of pump laser 215 and pump laser 216 outputs is from two input inputs of coupler 213, the pump light intensities of 213 pairs of inputs of coupler is redistributed at two outputs, and the output intensity of three couplers ratio is 1: 1 in the present embodiment.Two outputs of coupler 213 are connected with the input of coupler 211, coupler 212 respectively, and are coupled with the pump light of pump laser 214, pump laser 217 respectively.The pump light of 211 pairs of pump lasers 214 of coupler, coupler 213 outputs is coupled, and on average exports to two outputs then, i.e. two of pump light source device 21 output Out1, Out2; The pump light of 212 pairs of pump lasers 217 of coupler, coupler 213 outputs is coupled, then also fifty-fifty from two other output Out3, the Out4 output of pump light source device.

Adopt pump light source device as shown in Figure 3, in the time will regulating to gain amplifier, only need to change the power output of pump laser 215 or pump laser 216, at this moment, four output Out1, Out2 of pump light source device, the power output of Out3, Out4 change synchronously, the gain of four sections Er-doped fibers also changes synchronously, so can not influence the shape of whole Er-doped fiber gain amplifier curve.

Be that four sections Er-doped fiber cascades are amplified in the present embodiment, use be the pump light source access device that four pump lasers are coupled to form by three couplers, and the output of the power of each coupler is 1: 1 than all.But the utility model protection range is not limited only to so, can do suitably to adjust to pump light source as required.As three sections Er-doped fiber cascades are amplified, just can use pump light source device 31 as shown in Figure 4, this device comprises 313,314,315 and two couplers 311,312 of three pump lasers, and the pump light of its three output Out1, Out2, Out3 output is respectively as the pump light source of three sections Er-doped fibers.In addition, the power output of coupler was not limited to 1: 1 than also, can be made as other ratio as required, as 1: 2.

Claims

1, the pump light source access device of cascade Er-doped fiber amplification comprises at least two pump lasers, the pump light of its output is before inserting Er-doped fiber, close ripple by wavelength division multiplexer and flashlight, it is characterized in that: the pump light source access device also includes coupler, the pump light of described pump laser output is coupled through coupler earlier, and then exports to wavelength division multiplexer.

2, the pump light source access device of cascade Er-doped fiber amplification according to claim 1, it is characterized in that: described coupler is 2 * 2 couplers, its power output ratio is 1: 1; When the hop count of cascade Er-doped fiber is N (N 〉=2), be N as the pump laser number of pump light source light source, described 2 * 2 coupler numbers are N-1.

3, the pump light source access device that cascade Er-doped fiber according to claim 2 amplifies, it is characterized in that: described cascade Er-doped fiber is by Er-doped fiber (142), (152), (172), (182) totally four sections cascades form, described pump light source access device comprises four pump lasers (214), (215), (216), (217) and three couplers (211), (212), (213), pump laser (215), (216) Shu Chu pump light is located coupling at coupler (213), after coupler (213) averages distribution to pump light, two output respectively with pump laser (214), pump laser (217) is in coupler (211), coupler (212) is located coupling, coupler (211), (212) output is the output Out1 of pump light source access device, Out2, Out3, Out4.

4, the pump light source access device of cascade Er-doped fiber amplification according to claim 2, it is characterized in that: described cascade Er-doped fiber is to be formed by three sections Er-doped fiber cascades, and described pump light source access device comprises three pump lasers (313), (314), (315) and two couplers (311), (312).