CN1179222C - Multimode optical fiber and method of forming the same - Google Patents
Multimode optical fiber and method of forming the same Download PDFInfo
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Abstract
揭示一种多模光纤(10)，具有850nm窗口中大于220MHz.km的第一激光器带宽、850nm窗口中大于500MHz.km的第二激光器带宽、以及在300nm窗口中至少500MHz.km的第二OFL带宽。该多模光纤能够操作采用LED功率源和大功率激光器源的电信系统。还揭示制造和测试该多模光纤的方法。
A multimode optical fiber (10) is disclosed having a first laser bandwidth greater than 220 MHz.km in the 850 nm window, a second laser bandwidth greater than 500 MHz.km in the 850 nm window, and a second OFL bandwidth of at least 500 MHz.km in the 300 nm window. The multimode optical fiber is capable of operating a telecommunication system employing LED power sources and high-power laser sources. Methods of manufacturing and testing the multimode optical fiber are also disclosed.
Description
The mutual reference of related application
The application advocates the Application No. 60/121 that on February 22nd, 1999 submitted to here, the Application No. 60/174 that on January 6th, 169 and 2000 submitted to, 722 right of priority, the content of these two patented claims is all incorporated by reference at this, advocates the interests of right of priority here according to 35U.S.C. § 120.
Background of invention
1.
Technical field
The present invention relates generally to be used for the multimode optical fiber and the method for the system of the telecommunication system of low data rate and High Data Rate, relate in particular to optimized multimode optical fiber of application and method into modern LASER Light Source and the design of common LED source.
Though the present invention has wide range of applications, it especially is suitable for to equal or exceed the telecommunication system of 1Gbit/sec rate sending data.
2.
Technical background
The target of telecommunications industry generally is to send bigger quantity of information in the shorter time cycle on longer distance.As time goes on, show that this target is to can not see the moving target of terminal point.The increase of the frequency of using along with system user number and system also increases the demand of system resource thereupon.
Even to this day, data network provides service by the Local Area Network that adopts relatively low data transfer rate usually always.To this, light emitting diode (LED) is always and is the most common light source during these are used with continuing.Yet, along with data transfer rate begins to increase modulation capability above LED, system protocol from LED to the LASER Light Source transition.These transition obtain the most proximad and can transmit the confirmation of transfer of the system of information to equal or exceed 1Gbit/sec speed.
Transfer rate although it is so will strengthen the ability of LAN greatly, but for the owner of system, it can bring direct stake.The current multimode optical fiber that uses in telecommunication system mainly designs at using led light source, for using laser instrument generally is not best, and described laser instrument imagination is for sending in the information designed system and work being equal to or greater than 1Gbit/sec speed.Compare with led light source, LASER Light Source proposes different requirements to the multimode optical fiber quality with design.From historical point view, the index distribution at the fibre core place of multimode optical fiber has turned to led light source and has produced high bandwidth, and this trends towards fibre core is crossed injection.Combination results from the index distribution of the light distribution of led light source input pulse and optical fiber is crossed the injection way weighting, and this causes exporting pulse and has level and smooth relatively rising edge and negative edge.Although peak or flat-top by the little deviation generation of desirable nearly parabolic refractive index distribution can occur, their amplitude does not influence the system performance under the low data rate.Yet, in system based on laser instrument, the intensity distributions of light source with its power concentration near the center of multimode optical fiber.Therefore, the little deviation of fiber distribution can produce the obvious disturbance of rising edge of a pulse and negative edge, and this can bring big influence to system performance again.Itself can show this effect as too high time jitter, has the form of low bandwidth, perhaps the two.Although, regulate connection flexible cord or laser beam beam expander as the biasing emission mode by changing the luminescent condition of light source, can proofread and correct these defectives to a certain extent, this generally is not the owner's of system an actual solution.
The typical campus layout of LAN system designs for satisfying particular link length.The standard of campus trunk (transmitting between buildings) has the linkage length that reaches about 2km usually.Buildings trunk or standpipe (transmitting between architecture bottom layer) have usually and reach about 500 meters linkage length.Horizontal link length (transmitting between the office on the architecture bottom layer) has usually and reaches about 100 meters linkage length.Early stage and current lan technology can realize that with the standard class multimode optical fiber 2km length transmits as 10 megabit Ethernets.Yet, have Gbit/sec and more the system of future generation of high transmission rates ability with providing the standard multimode fiber of use can not realize all these linkage lengths at present.In the 850nm window, standard multimode fiber is limited in linkage length and is about 220 meters.In the 1300nm window, standard class optical fiber is limited in linkage length about only 550 meters.So present technology only can cover two kinds in three kinds of campus linkage lengths at the most.In order to make LAN have the Gbit/sec transfer rate fully, need the multimode optical fiber of the information that can on each of three kinds of linkage lengths, send.
As used herein, cross injection (OFL) definitions of bandwidth for utilizing EIA/TIA 455-51 FOTP-51A, the bandwidth of the canonical measure technology of describing in " pulse distortion of multimode glass fiber information transmission capacity is measured ", launching condition is by EIA/TIA 455-54A FOTP-54, " cross inject launching condition the pattern scrambler of multimode optical fiber is required " definition.
As used herein, laser bandwidth is defined as in EIA/TIA 455-51A FOTP-51 and the following two kinds of launching condition methods any described canonical measure technology and utilizes its measurement.Method (a) is used for determining the three dB bandwidth of 1300nm, and method (b) is used for determining the three dB bandwidth of 850nm.The method (a) that is used for determining the 3dB laser bandwidth at 1300nm place is utilized 4nm RMS spectral bandwidth 1300nm laser instrument, and the connection that connects flexible cord by 2 meters, standard ladder refractive index, around the single-mode fiber of twice in the 50mm diameter mould heart improves classification 5 coupled power ratios and launches.The central shaft that mechanically departs from multimode optical fiber by the central shaft that makes single-mode fiber by this way further improves launching condition, promptly the time makes single-mode fiber connect lateral excursion 4 μ m between the central shaft of fibre core of flexible cord and multimode optical fiber in test.Attention: describe and utilize its measurement in the process of classification 5 coupled power ratios in EIA/TIA526-14A OFSTP 14 appendix As " optical power loss that multimode optical fiber optical cable factory is installed is measured ".The method (b) that is used for the 3dB laser bandwidth of definite 850nm is utilized 0.85nmRMS spectral bandwidth 850nm OFL launching condition, as what describe among the EIA/TIA 455-54A FOTP-54, be connected to 1 meter long custom-designed multimode optical fiber, having 0.208 numerical aperture and graded index profile and α is 2.This optical fiber can produce by 50 μ m diameter standard fibre core multimode optical fibers are drawn to 23.5 μ m diameter fibre cores, and described standard multimode fiber has 1.3 refractive index (Δ=n
0 2-n
c 2)/2n
0n
c, n here
0The refractive index of=fibre core, n
cThe refractive index of=covering).
Current, in order to increase distance, manufacturer changes bandwidth by changing refractive index profile shape usually between two wavelength windows.According to the change of being done, result or have high OFL bandwidth and have low OFL bandwidth at the 1300nm window at the 850nm window, or have low OFL bandwidth and have high OFL bandwidth at the 1300nm window at 850nm.For example, for standard 2% Δ 62.5 μ m FDDI type optical fiber, can regulate index distribution, be created in the 1000MHz.km of 850nm place and in the OFL bandwidth of the 300MHz.km of 1300nm place, perhaps can regulate index distribution, be created in the 250MHz.km of 850nm place and in the OFL bandwidth of the 4000MHz.km of 1300nm place.Yet, to adopt to have this multimode optical waveguide fiber that standard " α " distributes, it can not be implemented in the 1000MHz.km of 850nm place and in the OFL bandwidth of the 4000MHz.km of 1300nm place.More generally, make that tolerance limit then allows 600MHz.km/300MHz.km or 200MHz.km/1000MHz.km but be not the 850nm/1300nm OFL bandwidth of 600MHz.km/1000MHz.km.
Yet, between these historical bandwidth change, exist discontinuously, this is essential for the Gbit/sec transfer rate.Owing to high-speed laser is a standard sources of transmitting the LAN that information designs with the above speed of Gbit/sec, therefore need have and on 850nm and 1300nm window, all have the multimode optical fiber that increases bandwidth.
Yet, because this LAN also is in its early stage of development, to satisfy or surpass that all required system elements of 1Gbit/sec transfer rate can't fully reduce or put into practice, optimization and/or test.Owing to these reasons, it is unpractiaca using to satisfying or surpassing alternative existing LAN system of the custom-designed new LAN system of this High Data Rate.As if though might realize this result, this is not preferable or best solution, because may cause system cost to raise and total system potential repeats work according to this action.
Summary of the invention
The present invention is meant and is the optimized multimode optical fiber of high-rate laser light source that described light source has the data transmission rate of 1.0,2.5 and 10 capital bps (Gbit/sec), surpasses linkage length requirement discussed above simultaneously.In addition, same multimode optical fiber is enough to keep high OFL bandwidth, is used in the 1300nm of present use in the LAN system and the transmission of 850nm led light source support information.This multimode optical fiber will make the current LAN owner of system can keep their present LED-based LAN systems, meanwhile make them can be easy to transfer to " capital bit Ethernet system ", need not to bear expensive multimode optical fiber upgrading.As used herein, " capital bit Ethernet system " is defined as can be to equal and/or to surpass the telecommunication system of the rate transmissioning data of 1Gbit/sec, as LAN.
So, one aspect of the present invention relates to a kind of multimode optical fiber, it have in the 850nm window greater than first laser bandwidth of 220MHz.km, in the 1300nm window greater than second laser bandwidth of 500MHz.km, in the 850nm window at least the OFL bandwidth of 160MHz.km, in the 1300nm window the 2nd OFL bandwidth of 500MHz.km at least.This multimode optical fiber has various application in telecommunications industry, especially be suitable for adopting in the telecommunication system of high-speed laser light source.This multimode optical fiber has the fringe benefit that enough OFL bandwidth are provided for the led light source of present use in the LAN system.
In yet another aspect, the present invention refer to a kind of can be to equal and to surpass the multimode transmission system of 1Gbit/sec rate transmissioning data.This multimode transmission system comprise the laser light source of launching 1Gbit/sec information at least and with the multimode optical fiber of this laser optical sources traffic.Multimode optical fiber has in the 850nm window first laser bandwidth of 385MHz.km at least, and it can carry at least 500 meters of information.Multimode optical fiber also has in the 1300nm window second laser bandwidth of 746MHz.km at least, and it carries at least 1000 meters of information.In addition, multimode optical fiber comprises the sufficiently high first and second OFL bandwidth for 850nm and the use of 1300nm led light source.
Another aspect of the present invention relates to a kind of multimode optical fiber with covering of 62.5 μ m fibre cores and this fibre core of constraint.The refractive index of covering is lower than the refractive index of fibre core, and multimode optical fiber presents DMD and distributes, and when the 1300nm wavelength measurement, it comprises that average gradient is from (r/a)
2=0.0 to 0.25 first area of measuring and average gradient are from (r/a)
2=0.25 to 0.50 second area of measuring.The slope of first area is preferably greater than the slope of second area.Better, the slope of first area is greater than 1.5 times of the slope of second area.
In yet another aspect, the present invention refers to a kind of method that forms multimode optical fiber.The method comprising the steps of: make the silica thermal chemical reaction that contains precursor reactant and at least a alloy reactant with formation cigarette ash, and to be enough to produce the mode with predetermined characteristic preformed glass part this cigarette ash is sent to target.Preformed glass part is drawn into the multimode optical fiber of clad region with 62.5 μ m core regions and this core region of constraint.Reactions steps comprises according to being enough to makes multimode optical fiber present smoke deposition formulation selection precursor reactant and alloy reactant that DMD distributes, and when in the 1300nm wavelength measurement, it has from (r/a)
2First average gradient that=0.0 to 0.25 first area is measured and from (r/a)
2Second average gradient that=0.25 to 0.50 second area is measured, first average gradient is greater than second average gradient.
Multimode optical fiber of the present invention can produce many advantages that are better than other multimode optical fibers well known in the prior art.A this advantage is the use that multimode optical fiber of the present invention can be taken into account high-speed laser light source and led light source fully.Therefore, multimode optical fiber of the present invention can use with the conventional local area that adopts led light source, and can use with capital bit Ethernet system, and the latter adopts the high-speed laser light source.
In addition, multimode optical fiber of the present invention has been eliminated needs expensive pattern to regulate the connection flexible cord to capital bit Ethernet system agreement, and this connection flexible cord usually is used to and can works in the 1300nm window.For many multimode optical fibers, the use pattern is regulated and is connected the center that software comes the power excursion multimode optical fiber, and to avoid the center line distribution defect, these defectives are normally produced by some manufacture process.Because preferable multimode optical fiber of the present invention utilizes OVD (OVD) manufacturing, preferable multimode optical fiber of the present invention has reduced the center line distribution defect.So, no longer need regulate to connect flexible cord preferable multimode optical fiber of the present invention worked in the 1300nm operation window with pattern, therefore owing to loosen the connector tolerance limit, allow in emission or a little skew in the heart, thereby causing being easy to installs and uses.
In addition, multimode optical fiber of the present invention makes the laser performance optimization of various laser light sources, laser light source such as (but being not limited to) 780nm fabry-Perot type laser, 850nm vertical cavity surface emitting laser (VCSEL), 1300nm fabry-Perot type laser and be the following low-cost 1300nm transmitter that uses of imagination.Multimode optical fiber of the present invention also is designed to be supported in when using with high-performance laser in more advanced telecommunication system on the important linkage length with 2.5 and the work of 10Gbit/sec speed.
In the following detailed description, will provide supplementary features of the present invention and advantage, for this area professional and technical personnel, a part is conspicuous from describe or is familiar with by implementing the present invention as described herein, describes to comprise the following detailed description, claims and accompanying drawing.
Should be appreciated that above general description and the following detailed description only are examples of the present invention, wishing provides a general introduction or framework for understanding essence of the present invention and the feature that claim advocates.The accompanying drawing that comprises provides further understanding of the present invention, is added in the instructions and constitutes the part of instructions.Description of drawings various embodiment of the present invention are with describing the principle of the invention and the work of illustrating.
The accompanying drawing summary
Fig. 1 is the skeleton view of the preferred embodiment of multimode optical fiber of the present invention.
Fig. 2 is the DMD distribution curve at the multimode optical fiber shown in Figure 1 of 1300nm place measurement.
Fig. 3 is the DMD distribution curve at the multimode optical fiber shown in Figure 1 of 850nm place measurement.
Fig. 4 is the DMD distribution curve in second preferred embodiment of the multimode optical fiber of the present invention of 1300nm measurement.
Fig. 5 is at the DMD distribution curve of the multimode optical fiber shown in Figure 1 of 1300nm measurement and the DMD distribution curve of the second preferred embodiment multimode optical fiber.
Fig. 6 illustrates for various LASER Light Source, the bandwidth of multimode optical fiber shown in Figure 1.
Fig. 7 is the refractive index distribution curve of first preferred embodiment of multimode optical fiber of the present invention, and it has DMD shown in Figure 2 and distributes.
Fig. 8 is the refractive index distribution curve of second preferred embodiment of multimode optical fiber of the present invention, and it has DMD shown in Figure 4 and distributes.
The detailed description of preferred embodiment
Disclosed the index distribution of multimode optical fiber, made its optimization at the application that utilizes modern LASER Light Source and led light source commonly used.The α index distribution is described radially continually varying distribution shape.In the present invention, index distribution preferably comprises at least two zones, has " α " index at least, be commonly referred to symbol (α), thereby make index distribution near near the optimized α of one or more LASER Light Source is changed to this distribution outside smoothly to the optimized α of LED (at one or more wavelength) this distribution center.Multimode optical fiber with this index distribution make distance and data rate capacity extend to simultaneously can with equal or exceed 1gbit/sec speed transmit information telecommunication system institute documentary evidence beyond.Because LASER Light Source has " luminous point " littler than LED, have now found that, according to the OFL bandwidth requirement (for the multimode optical fiber of 62.5 μ m fibre cores, be 160-200MHz.km typically at the 850nm place, at the 1300nm place is 500+MHz.km) can make the exterior section optimization of this distribution, and require and the light source feature for laser bandwidth, make the interior section optimization of this distribution simultaneously.Believe that this is first to distribute, it 1300nm and 850nm window on the two to the two optimization simultaneously of big luminous point LED and little luminous point laser instrument.Because 1300nm laser instrument luminous point even littler than the luminous point of shortwave (SX) laser light source, inner distribute to require to be preferably determine by the SX bandwidth requirement.Have been found that and when correctly making inner distribution optimization, can be implemented in shortwave (for example selected 780nm CD laser instrument or 850nm VCSEL) and long wave (for example 1300nm or 1500nm fabry-Perot type laser) the wide laser bandwidth on the two.
A key character of optimization index distribution is that it provides high 1300nm OFL bandwidth to led light source, thereby can realize superperformance to the adjusting of whole distribution with little laser instrument and/or in the distributive province that does not influence the OFL bandwidth performance.This also needs α (r) is the smooth function of r, rather than sudden change.
The present invention is directed to multimode optical fiber, it has to typical shortwave (for example 780,850 or 980nm) laser instrument and long wave (for example 1300nm or 1500nm) laser instrument provides high bandwidth and low time jitter and custom-designed index distribution is to keep enough high bandwidths and low jitter simultaneously when using with original 1300nm and 850nm led light source.
The index distribution of multimode optical fiber of the present invention can be described with several different methods.At first, in multimode optical fiber, the output pulse can be described as P with M pattern
Out(t)=∑ P
mδ (τ
m-τ
Ave), m pattern has relative power P here
mWith with respect to mean value τ
Ave=∑ P
mτ
m/ ∑ P
mMode delay τ
mOFL or laser bandwidth are by P
OutThe amplitude of fourier transform (t) is determined, if all τ
mIt is the then optimization that equates.
Mode delay τ
mDetermine by index distribution and operation wavelength.Mode power P
mDepend on the characteristic of light source (particular laser, LED etc.).Multimode optical fiber of the present invention preferably is designed to the overwhelming majority, and light source preferably all commonly used satisfies OFL or laser bandwidth requirement.For example, optical fiber require may be the OFL bandwidth respectively greater than the 160MHz.km and the 500MHz.km of 850nm and 1300nm led light source, laser bandwidth is respectively greater than the 385MHz.km and the 746MHz.km of 850nm VCSEL and 1300nm fabry-Perot type laser light source.
The second method of describing the index distribution of optical fiber relates to the refractive index or the germania composition of direct measurement fibre core.Typical multimode optical fiber is designed to have the refractive index that changes and be proportional to the germania composition with the function of radial position.This index distribution n (r) is by following function representation:
For r＜a, n (r)=n
1(1-2 Δ (r/a)
g)
0.5
Here n
1Be the refractive index of the center of fibre core, r is radial position, and a is the radius at fibre core covering interface, and g is the distribution shape parameter, and Δ is defined as:
Δ＝(n
1 2-n
0 2)/2n
1 2
Here n
0It is the refractive index value at fibre core-covering interface.This distribution is described and used the index " g " through being often expressed as α is common in works.This area professional uses this two terms interchangeably, can not obscure.
For purpose of the present invention, index distribution is defined as follows:
For 0＜r＜a, n (r)=n
1(1-2 Δ (r/a)
G (r))
0.5
Here g (r) is to radius continually varying distribution shape parameter, thereby satisfies above-mentioned OFL and laser bandwidth target in the first method of describing index distribution.Say that roughly near the relative power LASER Light Source of the pattern the center is bigger than led light source, Long Wavelength Laser (for example 1300nm fabry-Perot type laser) is bigger than short-wave laser light source (for example typical 850nmVCSEL light source).Therefore, intuitively, g (r) can be in the 850nm optimization from changing at middle radius in the 1300nm optimization in the center, again to be in the 1300nm optimization than long radius.In fact, the smaller value (more approaching equal 1300nm) of g (r) near the higher value the center (making the more approaching 780-850nm of equaling of mode delay) to the outside is suitable.In fact g (r) arrives below the value that is fit to 1300nm never wittingly.For the OFL bandwidth, it is important that g (r) changes smoothly and continuously.
Perhaps can the most easily find out this index distribution with the third method of describing index distribution with variation g (r).This method adopts the module of differentials known to those skilled in the art to postpone (DMD) and measures.Describe simply, this method relates to from the radially pulse scanning of the single-mode fiber by the multimode optical fiber fibre core, and measures the output pulse and with the average delay time with respect to the pulse of the different peripheral position emission of multimode optical fiber fibre core.Depict pulse daley the slope local of the function of radial position and DMD as to (r/a)
2Here " r " is defined as single-mode fiber with respect to radially the departing from of multimode optical fiber center (being the distance between the center of axle center and multimode optical fiber fibre core of single-mode fiber), " a " is defined as the radius of the fibre core of multimode optical fiber, near profile parameter g (r).The slope local of DMD is to (r/a)
2Curve is proportional to local g (r) with respect to the best g (or α) of setted wavelength and the Δ of multimode optical fiber.Relation between DMD, the refractive index sum of errors " α error " is that those skilled in the art know, and is described in following list of references.Measure and being described in more detail of technology for DMD, can be with reference to Marcuse showed
Optical fiber measurement former Reason, p.255-310 (Academic Press, 1981), " propagation in the glass optical waveguide " that its hereby incorporated by reference and OlshanskyR. are shown here
Rev.Mod.Phys., Vol.51, No.2, in April, 1979, p.341-367, here with its hereby incorporated by reference.According to preferred embodiment of the present invention, measured the OFL and the laser bandwidth (and DMD) of several optical fiber, and evaluation reaches the optical fiber of wider bandwidth to laser instrument and led light source with different refractivity distribution.The DMD of these best optical fiber characterizes required or target distribution to duplicating of additional multimode optical fiber.Utilize this empirical method of DMD not characterize the Pm of Different Light.Its effect but characterize the optical fiber of working with light source.
A critical aspects of the present invention is that the laser instrument intensity distributions is more much smaller than LED usually.Owing to this reason, in the middle of other factors, can make laser and LED operate the Refractive Index Profile o optimization of the two.According to one embodiment of the present of invention, 1300nm LED is made the exterior section optimization of index distribution, guarantee superperformance thus, promptly for original system OFL bandwidth greater than 500MHz.km.Make the interior section optimization of index distribution, provide equal laser bandwidth at 1300nm and 850nm place.By increasing this design, can repeat to produce the multimode optical fiber that the laser instrument of two kinds of wavelength is had high laser bandwidth and low jitter with the manufacturing technology that guarantees level and smooth variations in refractive index.
In detail with reference to preferred embodiment of the present invention, its example is described in the accompanying drawings now.In possible place, represent same or similar part with identical reference number in the accompanying drawings.Fig. 1 illustrates an example embodiment of multimode optical fiber of the present invention, represents this multimode optical fiber generally with reference number 10.
Preferable multimode optical fiber 10 is to have greater than the optimized 62.5 μ m multimode optical fibers of second laser bandwidth of 500MHz.km for having at the 850nm place greater than first laser bandwidth of 220MHz.km with at the 1300nm place.Yet, it will be understood to those of skill in the art that to make multimode optical fiber of the present invention on 850nm and 1300nm operation window, have big bandwidth equally, promptly at about 810nm and 890nm, more preferably at 830nm and 870nm and 1260nm and 1340nm, more preferably between about 1280nm and 1320nm.
In addition, preferable multimode optical fiber 10 is included in the 850nm window at least the OFL bandwidth of 160MHz.km and the 2nd OFL bandwidth of 500MHz.km at least in the 1300nm window.Yet better, multimode optical fiber 10 has 62.5 μ m fibre cores, and for designing in the minimum laser device bandwidth of the 385MHz.km of 850nm place with in the minimum laser device bandwidth of the 746MHz.km of 1300nm place.It should be noted that: 1300nm laser bandwidth above-described and that describe in whole instructions preferably should be measured with the 1300nm laser device that uses for standard single-mode fiber.This area many technician believe at present, can will need pattern regulate to connect flexible cord with the telecommunication system that equals or exceeds the 1Gbit/sec rate transmissioning data and be offset Laser emission on the 1300nm.Yet for multimode optical fiber of the present invention, the Laser emission on 1300nm is what to use along the main power measurement of multimode optical fiber central shaft emission.This is avoided needing this pattern to regulate connecting flexible cord, and reduction system is thus fulfiled, cost and complicacy.For the multimode optical fiber of 50 μ m fibre core (not shown), the minimum laser bandwidth preferably is 500MHz.km at the shortwave wavelength window, is 1648MHz.km at the long wave window.When adopting the multimode transmission system of using the high-speed laser light source, as with 1Gbit/sec rate emissioning data at least and during the telecommunication system that designs, the multimode optical fiber 10 with 62.5 μ m fibre cores 12 can be on the linkage length at least 500 meters on the shortwave wavelength and carrying 1Gbit/sec information at least on the long wave wavelength on 1000 meters linkage length.For the multimode optical fiber of 50 μ m fibre cores, these distances increase to linkage length above 600 meters and 2000 meters respectively.Yet this area professional will recognize that preferable multimode optical fiber 10 is not limited to the 1Gbit/sec transfer rate.But the present invention can be to surpass the data rate transport of 10Gbit/sec on important linkage length.Fig. 2 to 5 illustrates DMD and measures curve, indicates the multimode optical fiber of 62.5 μ m fibre cores to have the characteristic that is enough to satisfy above-mentioned running parameter.
The DMD that Fig. 2 illustrates the multimode optical fiber of making according to the present invention 10 measures curve 20.The DMD measurement result of multimode optical fiber 10 is to utilize obtaining at the 1300nm place based on the measuring technique of pulse of standard, and this technology type is similar to that Marcuse shows
The principle of optical fiber measurement, p.255-310 (Academic Press, 1981) and Olshansky R. " propagation in the glass optical waveguide " of being shown
Rev.Mod.Phys., Vol.51, No.2 describes in p.341-367 in April, 1979, and is here that it is incorporated by reference.Measure in the acclivitous zone of curve at 1300nm DMD, index distribution comes down to the wavelength less than 1300nm optimized, and in the downward-sloping zone of DMD curve, index distribution comes down to the wavelength greater than 1300nm optimized.Near in the smooth zone, index distribution comes down to 1300nm optimized at the DMD curve.
Fig. 3 illustrates and utilizes Photon-Kinetics Model2500 optical fiber measurement instrument on sale on the market to measure curve 30 at the DMD of the multimode optical fiber 10 of 850nm measurement.Have, in the zone that the DMD curve rises slightly, index distribution is optimized to the wavelength that is slightly less than 850nm again, and in the downward-sloping zone of DMD curve, its expression index distribution is optimized to the wavelength greater than 850nm.
The DMD that measures at 1300nm that Fig. 4 illustrates the second preferable multimode optical fiber (not shown) distributes 40.Although DMD distributes and 40 to be different from DMD slightly and to distribute 20, it describes the multimode optical fiber of required running parameter that its characteristic is enough to satisfy the multimode optical fiber of 62.5 μ m or 50 μ m fibre cores.
In Fig. 5 that the 1300nm place is measured the same width of cloth there is shown DMD distribute 20 and 40 the two.Made every curve offset, thereby made them similar (rather than (r/a) at slope
2=0) consistent on the common ground, this point is defined as zero (0) arbitrarily and is postponed.Say that loosely when measuring on the wavelength at 1300nm, target DMD distributes and comprises having from (r/a)
2The first area of=0.0 to 0.25 average gradient of measuring and having from (r/a)
2The second area of=0.25 to 0.50 average gradient of measuring, the slope of first area is greater than the slope of second area.Different sayings are that it is not linear that target DMD distributes.More preferably, the slope of the slope ratio second area of first area is at least 1.5 times greatly.Best, target DMD distributes and comprises from (r/a)
2The 3rd zone of=0.4 to 0.6 average gradient of measuring, wherein, DMD is from (r/a)
2=0.4 to 0.6 be changed to be many+0.20nsec/km.
Form multimode optical fiber and have the preferred approach that above-mentioned target DMD distributes according to the present invention and comprise step: make the silica thermal chemical reaction that contains precursor reactant and at least a alloy reactant to form cigarette ash, to be enough to produce mode this cigarette ash is sent to target, and preformed glass part is drawn into the multimode optical fiber with 62.5 μ m or 50 μ m core regions with predetermined characteristic preformed glass part.Reactions steps comprises according to being enough to makes multimode optical fiber present smoke deposition formulation selection precursor reactant and at least a alloy reactant that target DMD distributes.In preferred embodiment, the smoke deposition prescription comprises the SiCl of required ratio
4And GeCl
4, it causes satisfying the multimode optical fiber of the requirement of required target distribution.When in the 1300nm wavelength measurement, this multimode optical fiber has from (r/a)
2First average gradient of measuring on=0.0 to 0.25 first area and from (r/a)
2Second average gradient of measuring on=0.25 to 0.50 second area, first average gradient is greater than second average gradient.Yet, should be appreciated that to the invention is not restricted to SiCl
4And GeCl
4
Fig. 7 illustrate multimode optical fiber of the present invention first preferred embodiment (the same optical fiber that presents the DMD distribution curve of Fig. 2 and 3) be essentially parabolic refractive index distribution.Fig. 8 illustrate multimode optical fiber of the present invention second preferred embodiment (presenting the same optical fiber that the DMD of Fig. 4 distributes) be essentially parabolic refractive index distribution.Do not need these figure although implement the present invention as mentioned above, they have clearly demonstrated the benefit of DMD measuring technique used according to the present invention.Except shown in Fig. 7 and 8 a little difference in the index distribution disturbance on the index distribution peak region, for first and second preferred embodiments of multimode optical fiber of the present invention, other zones of index distribution are very similar.
Though do not specifically describe here, can similarly form multimode optical fiber with 50.0 μ m fibre cores.This area the professional will be understood that, the target DMD distribution that the target DMD of this multimode optical fiber distributes and will be different from the above-mentioned multimode optical fiber with 62.5 μ m fibre cores.Therefore, the smoke deposition prescription also will be different.Be further understood that, by slope region is defined as from (r/a)
2=0.0 to 0.2 first area and from (r/a)
2=0.2 to 0.4 second area can be described target DMD and distribute.
Example
To further know the present invention by following example, wish that described example is an example of the present invention.
Example 1
Test is to make one to have the optical fiber of required DMD characteristic and test it with various laser light sources to a kind of method of the performance of laser instrument optimization multimode optical fiber.Fig. 6 illustrates the result of this test.
To 850nm capital bit Ethernet system laser instrument, Fig. 6 illustrates ' effectively ' bandwidth (MHz.km) of the multimode optical fiber that is characterized by the distribution of DMD shown in Fig. 2-3 and 7 to various 780nm.Utilizing (OFL) bandwidth of filling excessively of the canonical measure of previous reference among the application and the optical fiber that lift-off technology is measured is 288MHz.km at the 850nm place, is 1054MHz.km at the 1300nm place.The laser bandwidth of utilizing among the application the canonical measure of previous reference and the optical fiber that lift-off technology is measured is that (that utilizes 23.5 μ m diameter fibre cores is connected flexible cord and the RMS spectral bandwidth 850nm light source laser instrument less than 0.85nm to 930MHz.km at the 850nm place, as described previously), be 2028MHz.km (utilizing exemplary needle) at the 1300nm place to single-mode fiber fabry-Perot type laser of using and the flexible cord that is connected that guarantees to depart from 4 μ m emission from core centre.' effectively ' bandwidth shown in Fig. 6 for various capital bit Ethernet system laser light source is to connect flexible cord with 23.5 μ m to use the measuring technique identical with the 850nm laser bandwidth that limits to measure, but launching condition changes with each capital bit Ethernet system laser instrument, because each laser instrument all has different distribute power in the near field with the far field.This demonstration utilizes optical fiber of the present invention can present big bandwidth with diversified laser instrument emission.About identical with several actual capital bit Ethernet system laser instruments acquisitions of the laser bandwidth that records with emission (930MHz.km) of qualification.Shortwave wavelength capital bit Ethernet system laser bandwidth obviously all surpasses the 850nm OFL bandwidth of 288MHz.km, and for to extend in the required scope of capital bit Ethernet system linkage length significantly.In addition, utilize double big than 1300nm OFL bandwidth of 1300nm laser bandwidth that the 1300nm fabry-Perot type laser measures with 4 μ m skew.
Example 2
As second example, to measuring the test optical fiber OFL bandwidth of measuring its index distribution shown in its DMD and Fig. 8 shown in Fig. 4, utilize 23.5 μ m to connect flexible cord for ' limited ' laser bandwidth at 850nm and utilize 4 μ m skew at 1300nm, for ' effectively ' bandwidth with one group of 13 capital bit Ethernet system laser instrument.Recording standard OFL bandwidth is 564MHz.km at 850nm, is 560MHz.km at 1300nm.Utilizing the connection flexible cord of 23.5 μ m diameter fibre cores is 826MHz.km in 850nm place ' limited ' laser bandwidth, utilizes the limited laser bandwidth value of fabry-Perot type laser of 4 μ m skew to be 5279MHz.km at 1300nm.' effectively ' bandwidth of measuring with 13 capital bit Ethernet system laser instruments at 850nm or 780nm is as follows: 1214,886,880,876,792,786,754,726,614,394,376,434 and 472MHz.km.Have, for limited laser instrument emission generation one bandwidth of 850nm with the connection flexible cord of 23.5 μ m diameter fibre cores, this bandwidth is near ' effectively ' bandwidth of seeing with several actual capital bit Ethernet laser light sources again.
Obviously can make various improvement and variation to the present invention to this area professional and technical personnel, and without departing from the spirit and scope of the present invention.Therefore wish that improvement of the present invention and the variation that provides in appended claims and the equivalent situation thereof is provided in the present invention.
Claims (15)
Applications Claiming Priority (2)
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|---|---|---|---|
| US12116999P | 1999-02-22 | 1999-02-22 | |
| US60/121,169 | 1999-02-22 |
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| CN1341217A CN1341217A (en) | 2002-03-20 |
| CN1179222C true CN1179222C (en) | 2004-12-08 |
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|---|---|---|---|
| CN00804063A Pending CN1341223A (en) | 1999-02-22 | 2000-02-22 | Laser optimized multimode fiber and method for use with laser and LED sources and system employing same |
| CNB008040346A Expired - Fee Related CN1179222C (en) | 1999-02-22 | 2000-02-22 | Multimode optical fiber and method of forming the same |
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| CN00804063A Pending CN1341223A (en) | 1999-02-22 | 2000-02-22 | Laser optimized multimode fiber and method for use with laser and LED sources and system employing same |
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| EP (2) | EP1181597A4 (en) |
| JP (3) | JP2002538489A (en) |
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| ID (1) | ID30246A (en) |
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| ZA (1) | ZA200105863B (en) |
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| NL1019004C2 (en) | 2001-09-20 | 2003-03-26 | Draka Fibre Technology Bv | Multimode fiber with a refractive index profile. |
| KR100526516B1 (en) * | 2003-07-11 | 2005-11-08 | 삼성전자주식회사 | Graded-index optical fiber for high bit-rate and local area network |
| NL1024015C2 (en) * | 2003-07-28 | 2005-02-01 | Draka Fibre Technology Bv | Multimode optical fiber provided with a refractive index profile, optical communication system using this and method for manufacturing such a fiber. |
| WO2005071381A1 (en) * | 2004-01-27 | 2005-08-04 | Fujikura Ltd. | Multi-mode optical fiber measurement method |
| KR100594062B1 (en) * | 2004-02-13 | 2006-06-30 | 삼성전자주식회사 | Optical fiber having the low discontinuity of the residual stress |
| WO2009022479A1 (en) | 2007-08-13 | 2009-02-19 | The Furukawa Electric Co., Ltd. | Optical fiber and optical fiber tape and optical interconnection system |
| FR2946436B1 (en) | 2009-06-05 | 2011-12-09 | Draka Comteq France | MULTIMODE OPTICAL FIBER WITH LARGE BANDWIDTH WITH AN OPTIMIZED HEAT-SLEEVE INTERFACE |
| US9014525B2 (en) | 2009-09-09 | 2015-04-21 | Draka Comteq, B.V. | Trench-assisted multimode optical fiber |
| EP2482106B1 (en) | 2011-01-31 | 2014-06-04 | Draka Comteq B.V. | Multimode fiber |
| FR2971061B1 (en) | 2011-01-31 | 2013-02-08 | Draka Comteq France | BROAD BANDWIDTH OPTICAL FIBER WITH LOW CURB LOSSES |
| EP2506044A1 (en) | 2011-03-29 | 2012-10-03 | Draka Comteq B.V. | Multimode optical fiber |
| EP2518546B1 (en) | 2011-04-27 | 2018-06-20 | Draka Comteq B.V. | High-bandwidth, radiation-resistant multimode optical fiber |
| DK2541292T3 (en) | 2011-07-01 | 2014-12-01 | Draka Comteq Bv | A multimode optical fiber |
| USD679194S1 (en) | 2012-02-10 | 2013-04-02 | Access Business Group International Llc | Container |
| USD779332S1 (en) | 2015-12-07 | 2017-02-21 | Access Business Group International Llc | Container |
| USD779333S1 (en) | 2015-12-07 | 2017-02-21 | Access Business Group International Llc | Container |
| WO2018136477A1 (en) * | 2017-01-19 | 2018-07-26 | Corning Incorporated | Distributed fiber sensors and systems employing hybridcore optical fibers |
| US10197726B2 (en) | 2017-06-22 | 2019-02-05 | Corning Incorporated | Wide-band multimode optical fibers with cores having a radially-dependent alpha profile |
Family Cites Families (10)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US3932162A (en) * | 1974-06-21 | 1976-01-13 | Corning Glass Works | Method of making glass optical waveguide |
| US4339174A (en) * | 1980-02-01 | 1982-07-13 | Corning Glass Works | High bandwidth optical waveguide |
| US4298365A (en) * | 1980-07-03 | 1981-11-03 | Corning Glass Works | Method of making a soot preform compositional profile |
| JPS60125810A (en) * | 1983-12-09 | 1985-07-05 | Dainichi Nippon Cables Ltd | Optical fiber |
| US4599098A (en) * | 1984-02-13 | 1986-07-08 | Lightwave Technologies, Inc. | Optical fiber and method of producing same |
| GB9605011D0 (en) * | 1996-03-08 | 1996-05-08 | Hewlett Packard Co | Multimode communications systems |
| JP3417200B2 (en) * | 1996-03-15 | 2003-06-16 | 住友電気工業株式会社 | Optical transmission / reception module |
| BR9707515A (en) * | 1996-12-16 | 1999-07-27 | Corning Inc | Germanium-doped silica forming supply stock and process |
| US5963349A (en) * | 1997-01-27 | 1999-10-05 | Lucent Technologies Inc. | Inexpensive single-fiber bidirectional data link |
| JP3989115B2 (en) * | 1999-02-08 | 2007-10-10 | 古河電気工業株式会社 | Multimode optical fiber |
-
2000
- 2000-02-22 KR KR1020017010691A patent/KR100609438B1/en not_active Expired - Fee Related
- 2000-02-22 EP EP00919331A patent/EP1181597A4/en not_active Withdrawn
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| CN1341223A (en) | 2002-03-20 |
| JP2010286850A (en) | 2010-12-24 |
| WO2000050941A1 (en) | 2000-08-31 |
| ZA200105863B (en) | 2002-02-21 |
| KR100657601B1 (en) | 2006-12-13 |
| JP2002538489A (en) | 2002-11-12 |
| AU3003400A (en) | 2000-09-14 |
| CN1341217A (en) | 2002-03-20 |
| CA2369436A1 (en) | 2000-08-31 |
| KR20010113708A (en) | 2001-12-28 |
| EP1153323A1 (en) | 2001-11-14 |
| ID30246A (en) | 2001-11-15 |
| BR0008415A (en) | 2002-01-29 |
| AU758337B2 (en) | 2003-03-20 |
| CA2363682A1 (en) | 2000-08-31 |
| AU4003500A (en) | 2000-09-14 |
| JP2002538065A (en) | 2002-11-12 |
| EP1181597A4 (en) | 2005-11-02 |
| KR100609438B1 (en) | 2006-08-03 |
| EP1153323A4 (en) | 2005-11-02 |
| WO2000050936A1 (en) | 2000-08-31 |
| KR20010113694A (en) | 2001-12-28 |
| EP1181597A1 (en) | 2002-02-27 |
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