CN101277153A - Optical coupler including mode-mixing - Google Patents

Abstract

A mode-mixer is used to introduce mode-mixing to an input in an optical coupler. As a result, modal noise effects are minimized in an output of the optical coupler. An example of a mode-mixer implemented includes a step index optical fiber which may or may not be coupled to a graded index optical fiber via a splice within an optical coupler. The splice may be a mechanical splice using connectors or a fused splice in some embodiments. The optical coupler may be included in a system for monitoring and/or analyzing a network.

Description

The optical coupler that comprises mode mixture

Related application

The application requires in the U.S. Provisional Application No.60/908 of submission on March 27th, 2007,396 interests.Its content is incorporated herein by reference.

Technical field

The present invention relates to the optical communication technique field, especially, relate to a kind of optical coupler and a kind of method that is used to handle light signal that comprises mode mixture.

Background technology

To need with high data rate transfer and the supervision and analyzing that receives the data network of data can the access network data flow, and do not destroy the operation of transfer of data or network.For this reason, adopted the surveillance of utilizing network tap, it is configured to catch the network data that is used to analyze, and the operation that does not jeopardize network.In the multimode fiber net, can use optical coupler, so that extract a part of light energy in the signal from main transmission path.The part of Chou Chuing can be received by optical receiver and data processor like this, so that make signal quality obtain analyzing and make optical fiber link obtain monitoring.

Optical coupler should have low-loss at main output, thereby the decay of main signal is minimized.In addition, owing to, require optical coupler to shift than the small part light energy with higher data rate for the loss budget of the reduction of higher data rate.Because most of light energy is retained in main output, therefore such optical coupler is called as " high splitting ratio optical coupler ".Finally, because the data rate increase, so bit period just reduces.The effect that the reducing of bit period increases corresponding to signal attenuation.

The summation of all these effects is exactly traditional multimode optical coupler can not work reliably under high bit rate (for example, like that high at 4 gigabits/per second (Gbps) at least).Therefore, because data rate increases, the operation that does not jeopardize transfer of data and network so some restrictions just provide reliable access network data flow to traditional optical coupler has produced obstacle.

Summary of the invention

A kind of optical coupler is disclosed.This optical coupler comprises input and is used to introduce the device of mode mixture.This optical coupler also comprises first output, second output and fiber optic splitter.This fiber optic splitter is configured to input and first output and second output are carried out optical coupling.

A kind of system is disclosed.This system comprises optical coupler.This optical coupler comprises input and is used to introduce the device of mode mixture.This optical coupler also comprises first output, second output and fiber optic splitter.This fiber optic splitter is configured to make the input and first output and second output to carry out optical coupling.This system also comprises first electronic equipment of the input that couples light to optical coupler.This system also comprises second electronic equipment of second output that couples light to optical coupler.

A kind of method that is used for handling the light signal that transmits at optical communication link is disclosed.This method comprises the light signal of mode mixture being introduced light signal and a part of mode mixture of transfer.

According to the following description and the appended claims, these and other aspects of the present invention will become more obvious.

Description of drawings

In order further to illustrate above-mentioned and other aspects of the present invention, will provide more specifically description of the present invention by the specific embodiment of middle explanation with reference to the accompanying drawings.Will be appreciated that these accompanying drawings have only provided exemplary embodiments of the present invention, therefore can not be considered to its scope is limited.To describe and explain the present invention by the use accompanying drawing and in conjunction with supplementary features and details, wherein:

Figure 1A and 1B are the eye pattern of explanation when the signal attenuation increase of data rate 30% tap output when 2Gbps (Figure 1A) is increased to 4Gbps (Figure 1B);

Fig. 2 A, 2B and 2C are that explanation does not have the optical coupler (Fig. 2 B) of mode mixture and comprises the eye pattern image of the difference of the signal attenuation between the optical coupler (Fig. 2 C) of mode mixture;

Fig. 3 A is the eye pattern of explanation shake (jitter) relative increase when bit rate increases with 3B;

Fig. 4 shows the example of optical coupler;

Fig. 5 A and 5B have illustrated before mode mixture (Fig. 5 A) and the cylindric pattern in (Fig. 5 B) optical fiber after mode mixture;

Fig. 6 shows the example of optical coupler;

Fig. 7 shows the example of optical coupler;

Fig. 8 shows the example of the high density tap that comprises a plurality of optical couplers;

Fig. 9 shows the example of the system that is used to monitor optical link; And

Figure 10 shows the example of the method that is used to handle light signal.

Embodiment

Traditional optical coupler can not carry out mode profile in optical fiber.Pattern is to keep or propagate the various possible pattern of electromagnetic field in optical fiber.The feature of pattern is by showing with wavelength, spatial distribution and the direction of its electromagnetic field component of the boundary-related of optical fiber and the field intensity of these components.

When the optical coupler splitting ratio increased, the probability of modal noise increased significantly in the fraction tap output.Modal noise stems from: when light signal between the most of main output of optical coupler and fraction tap output during by beam splitting, the power loss of the light signal of one or more patterns.This modal noise shows self as the shake that increases in the small part tap output, yet the signal of most of main output is not generally represented in such shake.

As disclosed herein, mode mixture is introduced into the input optical signal of optical coupler to reduce the modal noise in the tap output.Mode mixture relates to the transmission of power in the pattern, so that the mode profile of expectation is provided in optical fiber.As using herein, any equipment that can execution pattern mixes is described to " mode mixer " at this.And as use herein, term " tap " or " light tap " can refer to one or more optical couplers.Therefore, term " tap ", " optical coupler ", " light tap " and " light tap coupler " can be used alternatingly.

The result of this mode mixture is that the modal noise that extracts in the output reduces, thereby the waveform of the waveform of tap output signal and input optical signal is more similar.This effect is especially useful in high splitting ratio optical coupler is used.So optical coupler disclosed herein provides more reliable access to network data flow, so that be used for analyzing or other purposes in the situation that does not jeopardize the transfer of data and the network operation.

For the importance of the mode profile of understanding high splitting ratio optical coupler better, following is the short discussion of reflection each side of the present invention: the relation of (1) optical loss budget and splitting ratio; (2) relation of splitting ratio and modal noise; (3) next the relation of data rate and the signal attenuation such as shake is the discussion of several examples, and (4) optical coupler and (5) have merged the system and method for optical coupler.

I. the relation of optical loss budget and splitting ratio

Usually, in assembly or the system admissible light loss consumption budget limits according to optical loss.In optical communication system, loss is the luminous power that consumes in circuit or the assembly or the amount of energy, represents with decibel (dB) usually.Admissible loss total in the assembly such as cable, coupler and joint of optical loss the budget includes system distributes, and the system that makes designs with minimum cost under the tolerable bit error rate (BER).The transmitter power that requires, receiver sensitivity, interference loss and power hold sunken all being taken into account in the loss budget.

When data rate in the optical fiber data transmission system increased, the optical loss budget reduced.Thus, the optical loss budget of relative smaller portions can be arranged to the tap output of optical coupler.Therefore, in high-speed applications so, need have the optical coupler of higher splitting ratio.

In high splitting ratio optical coupler, greater number is meant a part of light energy of the main output that is coupled to optical coupler, and is meant the part light energy of the tap output that is coupled to optical coupler than peanut.For example, the high splitting ratio optical coupler that requires to be associated with 70: 30,80: 20 or higher splitting ratio substitutes 50: 50 splitting ratios, and is feasible from the less light energy of main output transfer.

The selection of the splitting ratio of the optical coupler that is used for optical link is indicated in the loss budget of given link usually.Can be the budget of fibre channel link computed losses in every way.A kind of mode is to determine the theoretical loss budget according to standard.For example, by following table 2 a kind of standard of inserting loss at the channel of 50 microns 2000Mhzkm multimode fibers has been described.

Fiber channel bit rate (Gbps)	Theoretical channel inserts loss (dB)
		1.0625	4.62
2.125	3.31
		4.25	2.48

Table 2

In addition, at different tap splitting ratios, main channel and tapping channel decay are considered in illustrated such of table 3 that can be as follows.

The MM tapping ratio	Line side decay (maximum) dB	Tap side decay (maximum) dB
			90∶10	1.3	10.8
80∶20	1.9	8
			70∶30	2.5	6.3
60∶40	3.2	4.9
			50∶50	4	4

Table 3

Therefore, for example, by the theoretical channel with the 4.25Gbps link insert in loss (2.48dB of table 2) and the given tap line side decay (secondary series of table 3) compare, can determine that tap in certain embodiments should have and not be higher than 70: 30 splitting ratio.Therefore, in high data rate applications, the minimizing of optical loss budget often need be used high splitting ratio optical coupler.

II. the relation of splitting ratio and modal noise

When the optical coupler splitting ratio increased, the probability of modal noise increased in the tap output of the optical coupler that does not use mode mixture.For example, having the optical coupler of 50: 50 splitting ratios will be than having 70: 30 or the optical coupler of higher splitting ratio has the probability of lower modal noise.Below the example shown in the table 4 effect (showing as caused shake) of the modal noise when bit rate increases has been described.

Fiber channel bit rate (Gbps)	Bit period (psec)	The closed cost (Eye Closure Penalty) of shake 80ps-eye pattern
			1.0625	941	8.50％
2.125	471	17.00％
			4.25	235	34.00％
8.5	118	68.00％

Table 4

Therefore, in lower data speed, the percentage of eye closure (eye closure) allows.Yet for example, at the bit rate of 4.25Gbps and 8.5Gbps, the shake shown in the table 4 begins to have a strong impact on systematic function.

With reference to Figure 1A, the image of eye pattern has been described, expression does not have the light signal of tap output of 70: 30 optical coupler of the 2Gbps of mode mixture.As shown in the figure, because all sample points of this eye pattern are located substantially on overlapping sheltering outside 100, remain very acceptable so shelter the tolerance limit test.On the other hand, under the situation of not introducing mode mixture, arrive 4Gbps by the bit rate (reducing bit period) that increases in the fiber coupler, shake related in the eye becomes more obvious, and in this eye and border, a lot of some samplings are fine, as among Figure 1B by shown in the dotted line 200, overlapping sheltering will be positioned at wherein.Yet the increase of the shake that obviously illustrates by relatively Figure 1A and Figure 1B is not the accurate expression of signal in the main output, because the corresponding increase of data rate, so described signal has experienced a spot of decay, as shown in Figure 1B.Further discussion about the relation of shake and modal noise is provided in the third part below.

Mode mixture is introduced light signal reduced loss of signal basically, described loss of signal is introduced in the tap output with the splitting ratio optical coupler of high data rate work.For example, with reference to figure 2A, the eye pattern image for the sampling of the 4Gbps input optical signal that arrives optical coupler has been described.Shown in Fig. 2 A, input optical signal is had the open basically eye of minimum jitter and signal skew and characterization.Usually, the eye pattern that is associated with the tap output of optical coupler should be similar as far as possible with the eye pattern of the signal shown in Fig. 2 A.

Fig. 2 B is the image of an eye pattern, and its expression does not have the light signal of tap output of 70: 30 splitting ratio optical couplers of mode mixture.Fig. 2 C has described the image of an eye pattern, and its expression has merged the light signal of tap output of 70: 30 splitting ratio optical couplers of mode mixture.As can be according to relatively the knowing of Fig. 2 B and 2C, the tap of Fig. 2 C output eye pattern than the tap output eye pattern of Fig. 2 B more similar in appearance to the input optical signal eye pattern of Fig. 2 A.Therefore, according to specific embodiment disclosed herein, by mode mixture being introduced the integrality of the signal in the tap output that light signal greatly strengthened optical coupler.

In addition, also can improve for the line speed that is higher than 4Gbps.In a test, as shown in following table 5, use 20 centimetres step index optical fiber (also being used for), the signal of extraction that is operated in 70: 30 splitting ratio optical couplers of about 10Gbps to show this improvement at the eye pattern shown in 4Gbps generation Fig. 2 C.

There is not mode mixture	70% output	30% output	Be input to tap
				Shake (rms)	3.23ps	4.35ps	3.32ps
Shelter tolerance limit	28％	-30％	30％
				Mode mixture is arranged
Shake (rms)	3.28ps	3.8ps	3.17ps
				Shelter tolerance limit	24％	15％	27％

Table 5

In the example of the 10Gbps shown in the table 5 owing to introduced mode mixture, shelter in the 30% tap output tolerance limit from-30% bring up to+15%.Therefore, introduce mode mixture at the 10Gbps data rate and reduced the modal noise that shows by the shake that increases, also like this for 4Gbps.

III. the relation of data rate and signal attenuation

As discussed above, modal noise is shown as the increase shake in the tap output of high splitting ratio optical coupler, and it does not show in input optical signal.Yet,, also become more remarkable owing to the bit period that reduces makes shake at least at high data rate.So, when data rate increases, reduce because the shake that modal noise causes becomes important further.

Shake is the regularly desirable of bias data signal, and generally measures from the zero passage of data-signal.In other words, the shake indicating impulse departs from its temporal ideal position.The method that is used to show degree of jitter comprises the generation of eye pattern.Eye pattern shows simultaneously on the base (overlaid time base) when repeating that generally a plurality of waveforms intersect.Eye pattern has presented the measurement of total shake (through the deterministic of combination and shake at random) and extinction coefficient (mean height is to the ratio of average low logic level).Eye pattern also is used to provide the visual representation of the eye pattern test specification whether link meet given standard, the standard such as fiber channel-general service 4 (FC-GS-4) (2004) standard, for example, the content of FC-GS-4 standard this by with reference to and merged.

Modern sampling oscilloscope can locate to show the shake block diagram at out-of-limit (threshold crossing), and can produce one " sheltering ", so that the identification shake is disturbed.Can discern shake by the sampling of the unacceptable number noted down in the circumference of sheltering disturbs.Yet, in order to satisfy standard, outside the pulse of sampling generally must be retained in fully and shelter.

When bit rate increases, cause that from modal noise the susceptibility of shake also increases.Illustrated as following table 6, when bit rate increased, bit period reduced pari passu.

Fiber channel bit rate Gbps	Bit period (psec)
		1.0625	941
2.125	471
		4.25	235
8.5	118

Table 6

The reducing of bit period causes in the eye pattern eye width is corresponding reducing.So, reduce to facilitate the shake that causes owing to modal noise to disturb the risk that increases owing to the bit period that reduces causes the corresponding of eye.

For example, with reference to figure 3A, the performance of expression with the eye pattern of the data-signal feature of first data rate transport has been described.Three time cycle tP 300A that represented main system clock.In Fig. 3 A, shake is represented by the width 305A of eyewall (walls).When shake increased, the space 310A of the center of eye pattern (comprising that eye is wide) reduced.Eye is wide to be good standard of measurement at the stability of data channel.

When data rate increased, the timing accuracy was more important to the systematic function change.This is not change owing to the value possibility of the shake of measuring with second is rough, but measures according to a part of bit period, and shake is along with the proportional increase of data rate and cause error.Like this, may be unacceptable in the admissible amount of jitter of lower data speed for relative higher data rate.

Fig. 3 B has illustrated the eye pattern of expression with the signal of the data rate transport that doubles the represented signal of the eye pattern shown in Fig. 3 A.For example, Fig. 3 A can represent the signal with the 2Gbps transmission, and Fig. 3 B can represent the signal with the 4Gbps transmission.As shown in Fig. 3 B, because the corresponding of the increase of data rate and time cycle tP 300B reduces to make that the shake 305B of every bit period increases.So, liken the wide amount of jitter 305B of eye to along with the proportional increase of data rate, and it is bigger to cause receiver wrong possibility to occur when whether the detection pulse exists.

IV. mode mixture optical coupler example

Mode mixer is used to improve the mode profile in the optical coupler.Improved mode profile is brought the modal noise of reduction, and wherein said modal noise is that the shake that reduces in the tap output by high splitting ratio optical coupler shows.Therefore, the tap output has been represented the waveform (although in high splitting ratio embodiment by more low level power) of the light signal that transmits in the main output more exactly.So the tap output signal is provided to monitor and the phase-split network data flow reliably, and the operation that does not jeopardize transfer of data or network.

Mode mixture also can be used for providing the mode profile that is independent of the source characteristic.There is not modal noise in the optical coupler of mode mixture to be entered the influence of the joint technology of using in the mode of the initial pattern of pattern of the light energy of optical fiber, the pattern by spread fiber and the fiber optic splitter yet.For example, mode profile can be dependent on the type in the source such as laser or light emitting diode that produces signal.And mode profile can be subjected to the influence of the optical assembly quality of the quality such as light source, optical fiber, light joint or light connect.By mixed mode in input optical signal, mode mixture compensation is distributed by the different mode that not homology characteristic and assembly quality cause, makes that modal noise reduces in the tap output, and irrelevant with the influence of light source type or optical assembly quality.

With reference to figure 4, optical coupler 400 has been described, it comprises the input 405 that is coupled to first output 410 and second output 415 by fiber optic splitter 435.Optical coupler 400 also comprises the device that is used to introduce mode mixture.In this example, the device that is used to introduce mode mixture is realized as the step index optical fiber 420 that couples light to a length of input 405.Optical coupler 400 also comprises the device that is used for the coupling light energy, and it couples light to gradient index fiber 425 with step index optical fiber 420.In embodiment illustrated in fig. 4, the device that is used for the coupling light energy is realized as mechanical splice 430.Mechanical splice 430 can be included in the step index optical fiber 420 of optical coupler 400 and the connector assembly of the pairing between the gradient index fiber 425.In certain embodiments, use industrial standard connector such as LC type optical connector to realize the connector assembly 430 that matches.

Fiber optic splitter 435 according to a certain relative percentage (splitting ratio) of light energy between first output 410 and second output 415 to the input optical signal beam split.In certain embodiments, be coupled to first output 410 the part light energy can total light energy of input signal about 10% to about 50% between.According to other embodiment, about 20% or about 30% of total light energy of input optical signal is transferred to first output 410.Yet scope of the present invention is not limited to the example of these splitting ratios.

By the pattern scattering of considering step index optical fiber 420 and the maximum bit rate that will transmit, can determine the length of step index optical fiber 420.Yet the length of step index optical fiber 420 optionally relies on bit rate basically.That is to say that the step index optical fiber 420 of certain-length can be for the bit rate of wide region, for example 4,8 or 10Gbps or higher bit rate, carry out sufficient mode mixture.Yet the length of step index optical fiber 420 can have introduces the necessary or manufactured process-bound minimum value that is associated of abundant mode mixture, such as being used for the desired minimum length of fusion splice below with reference to Fig. 6 discussion.

Step index optical fiber 420 can have the combination in any of length, diameter and numerical aperture (NA) attribute.For example, the length of step index optical fiber 420 can be about at least 2 centimetres, about 5 and about 100 centimetres between or between about 10 centimetres and about 20 centimetres (about 8 inches).The diameter of step index optical fiber 420 can be at least 25 microns, less than 200 microns, about 50 microns or about 62.5 microns.Also can select diameter, so that improved coupling (least power loss) is provided in the joint between step index optical fiber 420 and gradient index fiber 425.For example, the NA of step index optical fiber 420 can be about 0.2.In each example, the length of step index optical fiber 420, diameter and NA can be selected, make that when mode mixture is introduced input signal fully the transfer of data that optical coupler 400 can receive input 405 is to first output 410 and second output 415.

With reference to figure 5A, the representativeness of the cylinder transverse mode 500A in the optical fiber 505A distributed to be illustrated as: distribution can occur before execution pattern mixed process.Can be subjected to the example of the quasi-mode that mode mixer influences that the use of cylinder transverse mode is described by simple understanding, yet can obtain similar benefit according to the pattern of teaching other types disclosed herein.

In this example, pattern 500A is distributed in the middle body of optical fiber 505A usually as shown in figure.Therefore, which part light energy to be transferred to the tap output according to, the part of pattern 500A can not be coupled to this tap output of optical coupler at least.For example, shown in Fig. 5 A, if be transferred to the tap output of optical coupler from the light energy of the peripheral 510A of optical fiber 505A, pattern 500A may not can suitably be coupled to the tap output so.As second example,, have only sub-fraction pattern 500 can be coupled to the tap output of optical coupler so if be transferred to the tap output of optical coupler from the light energy of the lateral part 515A in the optical fiber 505A.The shake that the variation of modal loss (for example owing to optical fiber layout, source wavelength etc.) is illustrated as causing.

Yet,, illustrated in the expression of having carried out the mixed mode 500B after the mode mixture of pattern 500A with reference to figure 5B.Shown in Fig. 5 B, the pattern 500B of mixing fills optical fiber 505B more fully.As discussed here, when the increase of the speed of light transfer of data required higher splitting ratio optical coupler, such mode profile had increased the importance of optical coupling in the optical fiber.For example, as can be according to Fig. 5 A relatively learning to Fig. 5 B, if from peripheral 510B or transfer to the tap output of optical coupler from optical fiber 505B from the light energy of lateral part 515B, so because pattern 500B fills the cross section of optical fiber 505B more fully, so the possibility of modal loss is less after the mode mixture.And Fig. 5 B has illustrated and should be appreciated that any variation that has comprised mode profile in the teaching here by the optical fiber 505B that pattern is basically filled, and it is improved to the Mode Coupling of the tap output of optical coupler.

In a test relatively,, realized sheltering 131% improvement of the percentage of tolerance limit at 4Gbps for the introducing of mode mixture according to the result of 80: 20 splitting ratio optical couplers of the example of Fig. 4 explanation.More particularly, use the optical coupler do not have mode mixture, noted down-97% the tolerance limit of sheltering.Yet, use the optical coupler merged mode mixture, realized+34% shelter tolerance limit.And, after optical coupler being connected to bit error rate (BER) test (BERT) equipment, do not find error after 46 hours at the light signal that test 4Gbps extracts.

With reference to figure 6, optical coupler 600 has been described according to an exemplary embodiment.Optical coupler 600 illustrated in fig. 6 and optical coupler illustrated in fig. 4 400 are similar, wherein, optical coupler 600 comprises input 605, first output 610, second output, 615 ends, step index optical fiber 620, gradient index fiber 625 and fiber optic splitter 635.Yet according to embodiment illustrated in fig. 6, the device that is used for coupling light energy between step index optical fiber 620 and gradient index fiber 625 is implemented as fusion splice 630.Fusion splice is an optical fiber light joint, and enough heat melts this optical fiber light joint by applying, welding and be thus connected the termination of each section of two sections optical fiber, and to have at the fusion splice place be low-loss or near zero simple optical fiber so that form.Can realize the joint of any other type, such as joint, rotating machinery joint or the joint strap of ultraviolet curing or combination.

Yet some elements that are to be understood that specific embodiment disclosed herein can omit and/or be replaced.For example, can realize introducing other devices of mode mixture.The optical fiber of some relaxation equipment, surface-coated, bright and clean (finishe), machinery or optical disturbance and other types also can be introduced mode mixture.For example, in some specific embodiments, the optical fiber that mixes is used to replace step index optical fiber, or also can use the optical fiber that mixes except using step index optical fiber, so that introduce mode mixture.According to another example, by deposition technique any surface finish is applied to the input of optical coupler or is applied to any surface finish by the roughness with controlled amounts and introduce mode mixture.These various embodiment also can have the effect of introducing mode mixture.

Yet, use the gradient index fiber may be more reliable in some applications.And the use of gradient index fiber can not introduced in some applications may disadvantageous substantive decay or loss of signal.Therefore, although some embodiment may show the advantage that surpasses other embodiment in some applications,, can be implemented in any device of introducing mode mixture in the optical coupler according to teaching disclosed herein.

As another example,, can remove gradient index fiber so if do not need gradient index fiber for the function of fiber optic splitter.For example, with reference to figure 7, optical coupler 700 has been described according to an exemplary embodiment.Optical coupler 700 comprises input 705, first output 710, second output 715 and fiber optic splitter 720.Yet in this embodiment, whole input optical fibre 725 is step index optical fibers.Therefore, in this example, omitted the device that is used for coupling light energy between step index optical fiber and gradient index fiber at input.And gradient index fiber has also omitted from input optical fibre 725.Yet, for example by the connector assembly of pairing, from the outside to the optical coupler 700, gradient index fiber may be optically coupled to input optical fibre 725.

In one embodiment, first output optical fibre 730 and second output optical fibre 735 each all comprise or comprise step index optical fiber.According to another embodiment, only in first output optical fibre 730 or second output optical fibre 735 comprises or comprises step index optical fiber.For example, in one embodiment, second output optical fibre 735 is main outputs of high splitting ratio optical coupler and comprises step index optical fiber, yet first output optical fibre 730 is tap outputs of optical coupler and comprises gradient index fiber.

Optical coupler also can comprise overcoat, comprises the optical coupler of Fig. 4, Fig. 6 and/or Fig. 7 in this overcoat.Because this overcoat, manufacturer can stop the user to distort various elements basically.In another embodiment, gradient index fiber and fiber optic splitter can be contained in the overcoat, and step index optical fiber can be in the outside of overcoat, but are coupled to gradient index fiber by the connector such as the LC style connector.Therefore, by connection therebetween, can use the step index optical fiber wire jumper mode mixture to be incorporated into the input of optical coupler.

V. the system and method for implementation pattern mixed light coupler

Disclosed optical coupler can be integrated into high density light tap system among Fig. 4, Fig. 6 and/or Fig. 7.For example, with reference to figure 8, high density light tap 800 can comprise a plurality of optical coupler 805A-N the disclosed optical coupler in Fig. 4, Fig. 6 and/or Fig. 7.In one embodiment, high density light tap 800 can comprise the optical coupler 805A-N between about 4 and 32.Optical coupler 805A-N can be placed in the same direction, on the rightabout or equidirectional and rightabout combination.Can combined diagram 4, an example of the high density light tap of disclosed optical coupler among Fig. 6 and/or Fig. 7 is the high density TAP that the Finisar company in Sen Niweier city, markon Fo Niya state makes.Such high density tap embodiment can comprise fault-tolerant TAPs (traffic access point), and it can insert the storing communication amount from the both sides of full-duplex link with the speed of line speed.Such high density tap embodiment does not disturb basically for storage networking (or other networks), and provides the mode of incoming fiber optic channel traffic to monitor, analyzes and diagnose.Such high density tap embodiment can be minimized in the 1U frame that configuration can be installed has space shared in the chassis of 16 independent TAP.For example, utilize the selection of the splitting ratio of 50: 50,70: 30 or 80: 20, the optical coupler in the high density tap can be used for the optical fiber of 62.5 or 50 microns types.

Fig. 4,6 and 7 optical coupler can be used for extracting a part of luminous power from optical link.The luminous power that is extracted can be received by optical receiver and data processor, so that make that signal quality and optical fiber link obtain monitoring.Therefore, the optical coupler of Fig. 4, Fig. 6 and Fig. 7 can be to comprise the optical fiber link supervision of network analysis equipment and the part of analytical system.

Fig. 9 has illustrated the example of the system that is used to monitor optical link.This system comprises optical coupler 900.Optical coupler 900 comprises the device 905 that is used to introduce mode mixture.This optical coupler 900 also comprises fiber optic splitter 910.Optical coupler 900 comprises input 915, first output 920 and second output 925.Input 915 be optically coupled to first output 920 and second output 925 the two, make the data-signal that receives by input 915 be transferred to output 920 and output 925.

Described system also comprises first electronic equipment 930 of the input 915 that couples light to optical coupler 900.Described system also comprises second electronic equipment 935 of second output 925 that couples light to optical coupler 900.In one embodiment, depend on the network link that optical coupler 900 is coupled to, first electronic equipment 930 comprises network host equipment, and second electronic equipment 935 comprises the network switching equipment, and perhaps vice versa.

Described system also comprises the analytical equipment 940 that is coupled to first output 920.Analytical equipment 940 can be configured to monitor and/or analyze with at least 2,4,8 and/or the line speed of 10Gbps be transferred to the data of second electronic equipment 935 from first electronic equipment 930.An example of such analytical equipment 940 is NetwisdomProbe that the Finisar company in Sen Niweier city, markon Fo Niya state makes.Analytical equipment 940 can be connected on the link of network by the use of optical coupler 900.In this way, analytical equipment 940 can be collected all mutual (main frame is to memory device sessions) at the Initiator/Target/LUN layer, and the detail statistics about network health and performance is provided.Input 915 can be coupled to the interior fibre channel link (or link of other types) of network such as storage area network (SAN).Electronic equipment 930,935 and/or analytical equipment 940 can comprise the tester such as BERT equipment, oscilloscope, signal generator or other electronic test equipments.

With reference to Figure 10, the method that is used to handle light signal has been described.This method comprises mode mixture is incorporated into the input optical signal (1000) that transmits in the optical communication link.This method also is included in mode mixture and is introduced in input optical signal (1000) and migrates out a part of input optical signal (1005) from optical communication link afterwards.

Described method also comprises the analysis (1010) of carrying out input optical signal.This analysis can comprise related with input optical signal the determining of tolerance limit of sheltering.This analysis also can comprise: to sheltering of being associated with the part input optical signal that shifts from communication link hit (hits) (sheltering aging) be less than 5% increase determine.This analysis also can comprise the performance evaluation of the network that transmits input optical signal.

The part input optical signal that is shifted can be output to passive or active light device.For example, the part input optical signal that is shifted can be output to optical receiver, and the part input optical signal that this optical receiver will shift converts the signal of telecommunication to.The result of the described signal of telecommunication or analysis can be output to electronic equipment.The example of such electronic equipment comprises: no matter local computer, display, printer, the network switch, router, modulator-demodulator, physical storage medium, data processing equipment, detector, network analysis equipment, network test equipment, BERT equipment, oscilloscope or other electronic equipments of placing or placing by network.

Should be appreciated that accompanying drawing is the summary of this type of exemplary embodiment and schematically expresses, and therefore, should not limit the scope of the invention that described accompanying drawing also needn't draw in proportion.The present invention can be presented as other concrete forms and not depart from its spirit or inner characteristic.It is just illustrative in every respect that described specific embodiment is considered to, rather than restrictive.So claims more can show scope of the present invention than above stated specification.The all changes that come within the spirit and scope that are equivalent to claim all are comprised within its scope.Comprised detailed description to those of ordinary skills' known devices and treatment technology in the field of the invention.

Claims (38)

1. optical coupler comprises:

Input;

Be used to introduce the device of mode mixture, it is optically coupled to described input;

First output;

Second output; And

Fiber optic splitter, it is configured to make described input and described first output and described second output to carry out optical coupling.

2. optical coupler as claimed in claim 1, wherein, the described device that is used to introduce mode mixture comprises step index optical fiber.

3. optical coupler as claimed in claim 2, wherein, described input comprises gradient index fiber, wherein, described input also comprises the device that is used for coupling light energy between described step index optical fiber and described gradient index fiber.

4. optical coupler as claimed in claim 3, wherein, the described device that is used for the coupling light energy is included in the optical fiber splice between described step index optical fiber and the described gradient index fiber.

5. optical coupler as claimed in claim 4, wherein, described optical fiber splice is included in the fusion splice between described step index optical fiber and the described gradient index fiber.

6. optical coupler as claimed in claim 4, wherein, described optical fiber splice is included in the mechanical splice between described step index optical fiber and the described gradient index fiber.

7. optical coupler as claimed in claim 6, wherein, described mechanical splice is included in the connector assembly of the pairing between described step index optical fiber and the described gradient index fiber.

8. optical coupler as claimed in claim 7, wherein, the connector assembly of described pairing comprises the LC type optical connector of pairing.

9. optical coupler as claimed in claim 1, wherein, described first output comprises step index optical fiber.

10. optical coupler as claimed in claim 1, wherein, described second output comprises step index optical fiber.

11. optical coupler as claimed in claim 1, wherein, described optical coupler is associated with the splitting ratio of being scheduled to.

12. optical coupler as claimed in claim 11, wherein, described splitting ratio is between about 10: 90 and 50: 50.

13. optical coupler as claimed in claim 11, wherein, described splitting ratio is about 20: 80.

14. optical coupler as claimed in claim 11, wherein, described splitting ratio is about 30: 70.

15. optical coupler as claimed in claim 2, wherein, the length of described step index optical fiber is about 2 centimetres at least.

16. optical coupler as claimed in claim 2, wherein, the length of described step index optical fiber is between about 5 centimetres and about 100 centimetres.

17. optical coupler as claimed in claim 2, wherein, the length of described step index optical fiber is between about 10 centimetres and about 20 centimetres.

18. optical coupler as claimed in claim 2, wherein, the core diameter of described step index optical fiber be about 25 and about 200 microns between.

19. optical coupler as claimed in claim 2, wherein, the core diameter of described step index optical fiber is about 50 microns.

20. optical coupler as claimed in claim 2, wherein, the core diameter of described step index optical fiber is about 62.5 microns.

21. optical coupler as claimed in claim 1, wherein, described first output comprises first output optical fibre, and described second output comprises second output optical fibre, and described input comprises input optical fibre.

22. optical coupler as claimed in claim 1, wherein, the described device that is used to introduce mode mixture comprises attenuator, surface-coated, surface treatment, machinery or optical disturbance, the optical fiber that mixes or rough surface is handled.

23. a fiber channel tap comprises optical coupler as claimed in claim 1.

24. a fiber channel tap comprises at least two optical couplers as claimed in claim 1, and is configured to support to reach 10 gigabits/per second.

25. a fiber channel tap, be included in about 4 and about 32 between optical coupler as claimed in claim 1.

26. a system comprises:

Optical coupler, this optical coupler comprises:

Input;

Be used to introduce the device of mode mixture, it is optically coupled to described input;

First output;

Second output; And

Fiber optic splitter, it is configured to make described input and described first output and described second output to carry out optical coupling;

First electronic equipment, it is optically coupled to the described input of described optical coupler; And

Second electronic equipment, it is optically coupled to described second output of described optical coupler.

27. system as claimed in claim 26, wherein, the described device that is used to introduce mode mixture comprises step index optical fiber.

28. system as claimed in claim 26, wherein, described first electronic equipment comprises network host equipment, and described second electronic equipment comprises the network switching equipment.

29. system as claimed in claim 26 also comprises the analytical equipment that is coupled to described first output, this analytical equipment is configured to monitor and/or analyzes data from described first electronic equipment to described second electronic equipment.

30. system as claimed in claim 29, wherein, described analytical equipment comprises sensitive detection parts, and these sensitive detection parts are configured to the data of line speed from described first electronic equipment to described second electronic equipment with at least 4 gigabits/per second are monitored and/or analyze.

31. a method that is used for handling the light signal that transmits at optical communication link, this method comprises:

Mode mixture is introduced described light signal; And

Shift the light signal that a part is transmitted in described optical communication link.

32. method as claimed in claim 31, wherein, the described part optical signals that is transferred has the waveform of representing the photosignal waveform that transmits in the described optical communication link basically.

33. method as claimed in claim 31 also comprises:

Convert the described part optical signals that is transferred to the signal of telecommunication; And

The described signal of telecommunication is outputed to electronic equipment.

34. method as claimed in claim 31, wherein, the described light signal that transmits in described optical communication link is associated with the transmission rate of about at least 4 gigabits/per second.

35. a method that is used to analyze light signal comprises:

Enforcement of rights requires 31 processing; And

Analyze the described part optical signals that is transferred.

36. method as claimed in claim 35 wherein, at the tolerance limit of sheltering that is associated with the light data that received, is analyzed the data that received.

37. method as claimed in claim 36, wherein, the described tolerance limit of sheltering comprises the degeneration of sheltering less than 5%.

38. method as claimed in claim 35, wherein, described analysis comprises the analysis to the network that transmits described smooth data.

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