The method, private adapter and the installation method that suppress chromatic dispersion in the process of optical fiber conduction
Technical field
The present invention relates to optical field, particularly the inhibition method of optical transmission process chromatic dispersion and private adapter and its assemble method.
Background technology
Development along with optical communication technology, more and more higher to transmission rate request, the above technology of 10G is also more and more ripe and universal, for cost consideration, a lot of basic networks is still continued to use original multimode optical fiber transmission network, when reducing cost certainly, also attracted new problem, that is: since the optical fiber and digital communications be a series of pulse codes, the pulse strenching of optical fiber in transmission has caused pulse and pulsion phase overlapping phenomenon, has promptly produced intersymbol interference, thereby form the error of transmission code, cause mistake.For avoiding error code to occur, will elongate pulse distance, cause transfer rate to reduce, thereby reduced message capacity.As shown in Figure 8, on the other hand, the broadening degree of optical fiber pulse is more and more serious along with the growth of transmission range.As shown in Figure 9, therefore, for fear of error code, the transmission range of optical fiber also will shorten.Pulse strenching is that promptly pattern is a lot of because the intermode dispersion of multimode optical fiber causes, and the angle of multimode optical fiber incident light is a lot, each pattern arrives the time order and function difference of fibre-optic terminus, cause the broadening of pulse, thereby dispersion phenomenon occurred, caused the receiving end signal distortion.As shown in Figure 7, for the prerequisite at the existing fiber network is issued at a high speed and the purpose of long Distance Transmission, have only and reduce mode one way that is coupled in the multimode optical fiber, the system equipment end has proposed the requirement of the ring of light amount of working (Encircle Flux) to the optical module end for this reason, be to be coupled into the lock pin adapter after laser instrument sends the focusing of light process condenser lens, reenter multimode optical fiber then, the luminous flux that requirement enters multimode optical fiber is concentrated more good more, index is as follows: in the scope of the 10um of multimode optical fiber, want to receive 30% of whole laser instrument incident optical power, in the scope of the 22um of multimode optical fiber, to receive 81% of whole laser instrument incident optical power.This light that just requires laser instrument to send must go into to inject in the lock pin (Core) of lock pin adapter accurately, and requires hot spot the smaller the better (as shown in Figure 3).But exist two problems, 1. present technologies to be difficult to allow laser instrument and lock pin adapter at present in the perfect adaptation of focus place, particularly the XY axle is responsive more, Gaussian beam hot spot after burnt 2. laser instruments focus on through globe lens appears easily losing all greater than the fibre core of single-mode fiber, these two problems cause light to see through from the covering of lock pin all unavoidablely, form claddingmode, because the lock pin length of adapter is very short, generally can not surpass 5mm, be difficult to be eliminated at short interior these claddingmodes of 5mm distance, after back form with higher mode enters multimode optical fiber in case these claddingmodes come out from the lock pin adapter, very serious intermode dispersion will occur, cause the distorted signals (as shown in Figure 4) of receiving end.
At present the 10G light emission module of some function admirables being arranged also all is originally to make a search on one's body at condenser lens or laser instrument, obtains the littler laser beam of emission angle, but all expensive.
Summary of the invention
The method, private adapter and the installation method that suppress chromatic dispersion in the process of optical fiber conduction provided by the invention, be exactly on the basis of these mature technologies, other wards off the small stream footpath, make full use of the connection status of lock pin adapter in whole optical-fibre communications, the theory of coupling collar amount of working and resisting chromatic dispersion, the low-cost technical matters that solves the distorted signals that serious chromatic dispersion causes in the prior art.
The present invention is for solving the problems of the technologies described above the lock pin adapter that chromatic dispersion is provided in a kind of process of optical fiber conduction that provides, in comprising, establishes by this lock pin adapter the adapter tail cover of stepped hole, be embedded with ceramic sleeve in the first step hole of this stepped hole, the second step hole that this stepped hole is positioned at the rear end is used for wringing fit setting-in incident single mode ceramic insertion core, and lock pin base and adapter tail cover wringing fit press-fits and is one; Single mode ceramic insertion core in the middle of also being embedded with in the described ceramic sleeve, this centre single mode ceramic insertion core two ends is all ground the middle fiber core convex shape into rule, and the termination shape of this centre single mode ceramic insertion core is identical with the termination shape of incident single mode ceramic insertion core of intending inserting and ejaculation single mode ceramic insertion core insertion end.The middle fiber core convex shape at single mode ceramic insertion core two ends in the middle of described, intend the incident single mode ceramic insertion core that inserts and penetrate single mode ceramic insertion core termination shape being dome-type, and the curvature between the three is identical, the middle fiber core convex shape at single mode ceramic insertion core two ends in the middle of perhaps described, fiber core was a tack in the middle of incident single mode ceramic insertion core that plan is inserted and ejaculation single mode ceramic insertion core termination shape were, covering is the shape of the sphere or the conical surface on every side, and the curvature between the three is identical, described middle single mode ceramic insertion core, incident single mode ceramic insertion core and the center offset that penetrates between the single mode ceramic insertion core three are not more than 1 μ m.
And the assemble method of the lock pin adapter of this inhibition chromatic dispersion may further comprise the steps:
A. with two ends the middle single mode ceramic insertion core of middle fiber core convex is inlaid in ceramic sleeve in the wringing fit mode middle part;
B. the ejaculation single mode ceramic insertion core that with insertion end is middle fiber core convex is inlaid in the ceramic sleeve in the wringing fit mode, and the fibre core of the intermediate projections that penetrates single mode ceramic insertion core insertion end and the fibre core of middle single mode ceramic insertion core one end intermediate projections are conflicted;
C. the incident single mode ceramic insertion core that with insertion end is middle fiber core convex is inlaid in the adapter tail cover endoporus in the wringing fit mode, and this incident single mode ceramic insertion core insertion end is inlaid in the ceramic sleeve in the wringing fit mode, the fibre core of intermediate projections of incident single mode ceramic insertion core insertion end and the fibre core of middle single mode ceramic insertion core one end intermediate projections are conflicted;
D. ceramic sleeve is embedded in the adapter tail cover in the wringing fit mode together with setting-in fixing ejaculation single mode ceramic insertion core, incident single mode ceramic insertion core and middle single mode ceramic insertion core, the sleeve base is inlaid in the tail end of adapter tail cover in the wringing fit mode.
The order of above-mentioned first three step can be exchanged mutually, and to steps d, the center offset that requires in the installation process to keep penetrating single mode ceramic insertion core, incident single mode ceramic insertion core and middle single mode ceramic insertion core is not more than 1 μ m at step a.
The method that suppresses chromatic dispersion in this process of optical fiber conduction may further comprise the steps: at first the head of incident single mode ceramic insertion core in butt joint optical fiber and ejaculation single mode ceramic insertion core all grinds to form the middle fiber core convex shape of rule, and be taken to less a bit of middle single mode ceramic insertion core, also can be middle single mode ceramic insertion core butt joint more than two sections or two sections, each section all grinds to form middle single mode ceramic insertion core two ends the middle fiber core convex shape of rule; With incident single mode ceramic insertion core, middle single mode ceramic insertion core and penetrate the single mode ceramic insertion core successively wringing fit pack in the same ceramic sleeve, make to keep fiber core contact, the state of peripheral covering air insulated between above-mentioned three optical fiber; And guarantee incident single mode ceramic insertion core and penetrate single mode ceramic insertion core to small part cylinder to embed in the ceramic sleeve, consume claddingmode with air insulated.
The present invention compared with prior art has the following advantages:
1. these " simple lights " can be coupled into multimode optical fiber near the parallel hot spot of 9um hot spot from second section lock pin of adapter, guaranteed the concentration degree of luminous flux in multimode optical fiber well, the luminous flux that can receive in the fibre core scope of 10um more than 30% can be satisfied, the belt flux index of the luminous flux more than 81% can be received in the fibre core scope of 22um;
2. the angle of light degree that is coupled into multimode optical fiber is single, substantially all is low order mode and basic mode, and the harm with intermode dispersion drops to minimum substantially;
3. cost is lower, and can realize on existing lock pin adapter, is convenient to transform, and avoids waste.
Description of drawings
Accompanying drawing 1 is the synoptic diagram of conventional lock pin adapter structure.Accompanying drawing 2 is synoptic diagram of resisting chromatic dispersion lock pin adapter structure of the present invention.Accompanying drawing 3 be conventional lock pin adapter and laser instrument under ideal coupling situation, observe the synoptic diagram that light enters mode in the multimode lock pin.Accompanying drawing 4 is that conventional lock pin adapter and laser instrument are losing under the burnt situation about being coupled, and observation light enters the synoptic diagram of mode in the multimode optical fiber lock pin.Accompanying drawing 5 is lock pin adapter of the present invention and laser instrument are observed mode in the multimode lock pin under the situation of losing burnt coupling synoptic diagram.The synoptic diagram of accompanying drawing 6 lock pin adapters and multimode Transmission Fibers lock pin.The formation synoptic diagram of the intermode dispersion of accompanying drawing 7 multimode optical fibers.The intermode dispersion of accompanying drawing 8 multimode optical fibers and the transfer rate of fiber-optic signal concern synoptic diagram.The intermode dispersion of accompanying drawing 9 multimode optical fibers and the transmission range of fiber-optic signal concern synoptic diagram.
Embodiment
In conjunction with above-mentioned description of drawings specific embodiments of the invention.
By among Fig. 2 as can be known, establish the adapter tail cover 10 of stepped hole 20 in the lock pin adapter of inhibition chromatic dispersion comprises in this process of optical fiber conduction, be embedded with ceramic sleeve 40 in the first step hole 21 of this stepped hole 20, the second step hole 22 that this stepped hole 20 is positioned at the rear end is used for wringing fit setting-in incident single mode ceramic insertion core 61, and lock pin base 50 and adapter tail overlap 10 wringing fits and press-fit and be one; Single mode ceramic insertion core 60 in the middle of also being embedded with in the described ceramic sleeve 40, these centre single mode ceramic insertion core 60 two ends are all ground the middle fiber core convex shape into rule, and the termination shape of this centre single mode ceramic insertion core is identical with the termination shape of incident single mode ceramic insertion core of intending inserting 61 and ejaculation single mode ceramic insertion core 62 insertion ends.The middle fiber core convex shape at single mode ceramic insertion core 60 two ends, the incident single mode ceramic insertion core of intending insertion and ejaculation single mode ceramic insertion core termination shape are dome-type in the middle of described, and the curvature between the three is identical.Middle the fiber core convex shape at single mode ceramic insertion core 60 two ends in the middle of perhaps described, intend the incident single mode ceramic insertion core that inserts and penetrate single mode ceramic insertion core termination shape be in the middle of the tack shape of covering sphere or the conical surface on every side, and the curvature between the three is identical.
The assemble method that suppresses the lock pin adapter of chromatic dispersion among the present invention is: with two ends is the middle single mode ceramic insertion core of middle fiber core convex is inlaid in ceramic sleeve in the wringing fit mode middle part; With insertion end is that the ejaculation single mode ceramic insertion core of middle fiber core convex is inlaid in the ceramic sleeve in the wringing fit mode, makes the fibre core of the intermediate projections that penetrates single mode ceramic insertion core insertion end and the fibre core conflict of the intermediate projections of middle single mode ceramic insertion core one end; The incident single mode ceramic insertion core that with insertion end is middle fiber core convex is inlaid in the adapter tail cover endoporus in the wringing fit mode, and this incident single mode ceramic insertion core insertion end is inlaid in the ceramic sleeve in the wringing fit mode, the fibre core of the intermediate projections of the fibre core of intermediate projections of incident single mode ceramic insertion core insertion end and middle single mode ceramic insertion core one end is conflicted; Ceramic sleeve is embedded in the adapter tail cover in the wringing fit mode together with setting-in fixing ejaculation single mode ceramic insertion core, incident single mode ceramic insertion core and middle single mode ceramic insertion core, the sleeve base is inlaid in the tail end that the adapter tail overlaps in the wringing fit mode, and the center offset that requires to keep penetrating single mode ceramic insertion core, incident single mode ceramic insertion core and middle single mode ceramic insertion core in installation process is not more than 1 μ m.High-precision incident single mode ceramic insertion core is pressed in the adapter tail cover, adopt wringing fit between the two, ceramic sleeve is enclosed within on the incident single mode ceramic insertion core, will penetrates the single mode ceramic insertion core again and inject ceramic sleeve, then lock pin base and adapter tail casing pressure are made into one.Ceramic sleeve can guarantee that two sections close coaxial between the ceramic insertion core cooperate.Behind the covering of the incident single mode ceramic insertion core that is optically coupled into the lock pin adapter, can be depleted at the joint of incident single mode ceramic insertion core and ejaculation single mode ceramic insertion core, the light that comes out from ejaculation single mode ceramic insertion core almost is exactly the light of single mode like this, after the light of single mode goes into to inject multimode optical fiber, in multimode optical fiber, just have little intermode dispersion.Thereby guarantee that transmission signals can high speed longer transmission distance transmission in multimode optical fiber.
The inhibition principle that suppresses chromatic dispersion lock pin adapter in this process of optical fiber conduction is: with incident single mode ceramic insertion core, middle single mode ceramic insertion core and penetrate the single mode ceramic insertion core successively wringing fit pack in the same ceramic sleeve, make and keep fiber core contact, the state of peripheral covering air insulated between above-mentioned three optical fiber; And guarantee incident single mode ceramic insertion core and penetrate single mode ceramic insertion core to small part cylinder to embed in the ceramic sleeve, consume claddingmode with air insulated.
Ceramic insertion core is divided into two sections, and the place of contact all grinds to form sphere, and then these two sections lock pins are docked with the very high ceramic sleeve of precision.Be coupled into first section single mode lock pin (incident single mode ceramic insertion core) after after laser instrument sends light, focusing on by globe lens, but because the Gaussian beam after focusing on is greater than fiber core (Core) even mode field diameter (Mode Field Diameter), therefore can see through from fibre cladding (Cladding) by some light inevitably, this part light is claddingmode (6 lock pin structure with reference to the accompanying drawings), when these claddingmodes are transferred to junction between the first section lock pin and the second claddingmode attitude section lock pin, because two sections lock pins connect between fibre core (core), be exactly the air dielectric that disconnects substantially between the covering, therefore this part claddingmode can be lost by air dielectric in the junction substantially, only remain the light that transmits and just can be coupled into the second fiber stub in fibre core, the laser that therefore transmits in the second fiber stub almost is without any the low order of higher mode and basic mode light (with reference to the accompanying drawings 5).
Above content be in conjunction with concrete preferred implementation to further describing that the present invention did, can not assert that concrete enforcement of the present invention is confined to these explanations.For the general technical staff of the technical field of the invention, without departing from the inventive concept of the premise, can also make some simple deduction or replace, all should be considered as belonging to protection scope of the present invention.