TW454099B - Multicore and multimode dispersion managed fibers - Google Patents

Abstract

Optical pathways along optical fibers, including multiple cores or multiple modes, are arranged with positive and negative dispersion characteristics. Coupling or connecting mechanisms regulate relative lengths of travel between the pathways having different dispersion characteristics so the total dispersion of the combined pathways approaches zero dispersion over a range of signal wavelengths intended for transmission.

Description

45 4 09 9

Monthly work of the Central German Bureau of the Ministry of Economic Affairs: ^-;!;.; 4:-; >:,; ...- !! ^,:;? Invention Field:. The present invention relates to the US Patent Application No. 60/100495 filed on September 16, 1998. The date of the patent is the priority application date of this case. The optical signal running in the standard optical fiber medium has a relatively small change, and the optical signal will cause significant losses in the distance. —The term change includes light dispersion. The dispersion management fiber has positive and negative dispersion characteristics, and its length and average dispersion product are close to zero dispersion. Background of the invention: Light dispersion changes along the waveguide as a function of waveguide material and structure. Zero dispersion is possible at a fixed wavelength, but zero dispersion is about "four-wave mixed water, which produces crosstalk in adjacent wavelength channels." Four-wave mixing is most significant in the case of zero dispersion, but it increases with optical power and reduced channel spacing. Optical dispersion and four-wave mixing can be avoided by the dispersion management fiber, which combines positive and negative dispersion fibers (at the pre-transmitted wavelength). Because only using zero-dispersion fiber will avoid four-wave mixing. The term uses positive dispersion fibers to transmit optical signals through long distances and the dispersion compensation module contains roll-shaped negative dispersion fibers to periodically insert the dispersion fibers to reduce the average dispersion of the combined optical path. However, the imitation module will reduce the signal power without moving the signal towards its intended purpose. The ends of the positive and negative dispersion fibers are spliced together to transmit optical signals more efficiently and reduce optical dispersion. However, it is necessary to plan to keep track of the dispersion characteristics of the combined fibers, and to keep two different fibers in stock.

GM China National Standard (CNS) Λ4 specification (_ 210X m mm) (read the precautions on the back before filling this page). ^. --5 Line 454 09 954 09 9 V. Description of the invention (2- A7 B7 via the central part of the drop section # -offset elimination: Dispersion management fiber is also manufactured as a continuous length, which has alternating sections, which have the opposite dispersion sign at the wavelength to be transmitted. Only one fiber is required to be stocked, However, the dispersion period must be selected at the time of manufacture (ie, repeating the length of the two sections) and cannot be changed later. Contamination may also enter the fiber at the interface between the sections, which is drawn into the final form · It is also necessary to add the light and combination separately. The dispersion management cable contains one or more pairs of optical fibers, and the dispersion symbols are opposite. The segments of the cables are spliced together so that a segment of positive dispersion fiber is connected. Negative dispersion fibers to adjacent sections. Again, the dispersion plan that needs to track the length of the section and the design of the individual fibers are limited because the opposite sign dispersion must be equal in size at the transmission wavelength. Important: The present invention includes various embodiments of optical systems that compensate for optical dispersion and avoid four-wave mixing, while reducing the fiber inventory and providing more flexibility and fiber characteristics in the design. At the same time, it may be a shorter dispersion period (that is, repeating in The length within the dispersion variation) does not complicate manufacturing and other dispersion parameter selection after manufacturing. One. An embodiment is a dispersion-compensated fiber system that includes a single-mode fiber that has a set of multiple continuous optics Path, which has different dispersion characteristics to transmit optical signals. One optical path exhibits positive dispersion at the central wavelength of the optical signal and the other optical path exhibits negative dispersion at the central wavelength of the optical signal. Coupling mechanism shift The optical signal is between the two forward parts of the path. At the central wavelength of the optical signal, the path length multiplied by the average dispersion value is close to zero. Preferentially, the dispersion and dispersion slope are in the middle (CNS) Λ4 specification (210X 297 male axe). r (please read the precautions before filling this page)

、 -J ------. I 1 1-: 11 • mu t .......--mt · ίκΊ Β7 V. Description of the invention ίΐίΓ is matched so that the average dispersion in the entire wavelength range is close to (Please read the precautions on the back before filling in this page) Even if the optical pavement of the stomach and the stomach extend in parallel or intently, and the frequency is equal to the number of cars, the signal deviation of the road scale will not interfere with it! A sweet road. For example, a single-fiber can be manufactured with -groups of multiple cores =, f wrapped around. Each core forms an optical path, which has different dispersion characteristics. The ^ number is enough to be a combination of one or more long-term jobs and = a positive shift in heart. The _he mechanism can make the heart's place quite close to each other by the distance between the cores and cores to maintain the signal transfer. The latter coupling mode requires symmetrical dispersion characteristics between the cores and a length of 1¾ between the cores. Anterior green mold clamping energy_By shifting between the cores and cores at unequal distances, the dispersion of the cores will be more flexible. For the mold coin, the dispersion slopes of the positive value and the positive value dispersion 4 are matched preferentially (for example, with low values or opposite signs) so that the average dispersion is kept close to zero. ′, ^ Another implementation includes a fiber section that has one or more pairs of opposite sign dispersion and dispersion characteristics. The end of the segment is spliced into a twist opposite the end. It has one segment positive dispersion core and the other color ^ core. The length of the segment is chosen so that the product of the length and the average button value approaches zero. Each pair of cores can transmit signals in parallel, which is achieved by the absolute saturation t of positive and negative dispersion t and by the cores of the S-segment aligned to the adjacent segment, the adjacent area Segments are positive and negative dispersion with opposite signs. Many pairs of positive and negative dispersive cores can be independently arranged to maintain greater than one degree. Applicable to China National Standard (CNS) 8 4 specifications (210 X m mm) 454 09 9 8 7 B7 5. Description of the invention (屮)

I-¾ edit rate or transfer. The large jigsaws of the pigment tj level can be made possible by controlling the angular notches between adjacent sections to align different combinations of multiple cores, which have different dispersion characteristics. A single optical fiber can also be manufactured as a multimode fiber with a fundamental mode path and a higher order mode path with different dispersion values to form concentric circular optical paths with different dispersion characteristics. The coupling mechanism of this further embodiment includes one or more mode light couplers, which can also be formed as gradually changing consumable or long-period gratings to bias optical signals between the fundamental mode and the higher mode path. .. Fundamental modes can be arranged to exhibit positive dispersion, and higher order modes can be arranged to exhibit negative dispersion with smaller values. Thus, the arrayed mode couplers are placed as offset optical signals into the fundamental mode as longer distances than the higher order modes. However, with proper core distribution and selection of the normalized frequency, the dispersion and dispersion slope of the fundamental and second-order modes can be phase-specific, but with opposite signs. At the same time, it is possible that the better signal limit is far away from the mode cutoff value at the standardized frequency value. Different connectors can be used in multi-core or multi-mode fibers to transmit signals into single-mode single-core fibers. For example, a grating can be used to shift the optical signal from one core to another core, which is aligned with a single-mode single core fiber or from a higher order to the fundamental mode for further transmission through a single-mode single core fiber . Gradual coupling can also be used to force the signal into a single stamen or into the fundamental mode. In addition, the separated single-mode single-core ‘black fiber can be connected to different cores of a multi-core fiber, and a switch can be used to further transmit signals from a link fiber to a common single-mode single-core fiber. '(Please read the precautions on the back before filling in this page)

、 1T line. The scale of Zhang ’s scale is in accordance with the general Chinese solid standard (CNS) Λ4 specification (210X297 mm) ^ 54 09 9 A7 ——_ B7 V. Description of the invention (.f) (Please read the notes on the back before filling in this Page) Multimode fiber can be manufactured using traditional processing, which has modal dispersion characteristics. Multi-core fiber can be combined in a preform before traditionally pulling fiber by combining two or more core rods. Different arrangement of pipes or rods can be used to align and separate the core core members, and the dust cover can be consolidated to the core core; ^ surrounded by a closed structure in the preform. Brief description of the drawings: The first diagram (Figure 1A) is an enlarged view of a multi-core fiber, which has two offset cores with different dispersion characteristics. Figure 1B (Figure 1B) is similar to another multi-core fiber; ^ large figure, which has a central core and an offset core, which have different dispersion characteristics. The first C figure (Figure 1C) is a similar enlarged view of another multi-core fiber, which has two concentric cores with different dispersion characteristics. The second image is a smaller enlarged side view showing the lengths of two segments that are relatively rotated and spliced together. The first three graphs (Fig. 3A) and the third graph (Fig. 3B) contain the refractive index distribution of the two cores of the core. The refractive index is a function of the radius of the cores " r ". Figures II.C (Single. 3C) to third. Figures (Figure 3F) contain alternate refractive index distributions, which are particularly suitable for achieving negative dispersion. The fourth figure (Figure 4) is another schematic view of a multi-core fiber that includes a long-period grating to optically couple the two cores. The fifth figure (FIG. 5) is an enlarged end view of a multi-core fiber with four cores, in which two cores have positive dispersion characteristics and two have negative dispersion characteristics. The sixth figure (Figure 6) is a side view of gradually changing coupling to connect multiple paper sizes in Figure 1A. It is applicable to China National Standards (CNS) Λ4 specification (210 X 297 cm)-09 9. The two cores of the core fiber Core to traditional single core fiber. Figure = (Figure 7) is a side view of the light closing, the offset signal is between the two core fiber ^ and the connection ◎, this connector connects the two core fiber of the multi core fiber-to the traditional single- Heart Core of Heart Fiber. The eighth figure (Figure 8) is a side view of a multimode optical fiber, which has a continuous long-period grating with a non-patterning mode and a non-patterning mode. —The ninth figure (Figure 9) is the standardization transmission using the step-distribution core design as an example. The curve diagram of the sowing reed bn and the standardized frequency of multimode fiber ". The tenth figure (Fig. 10) is a graph showing the normalized waveguide dispersion dn and the waveguide normalized frequency, .ν "of the same step-separated heart core meter. The tenth figure (Fig. 11) is to support two core members An enlarged end view of the hole-shaped member. The tenth-figure (fig. 12) is an end view of the same size that supports the two core rods in the tube. An end view of the same size where two core rods are glued together. Figure 24 (®14) corrects an end shelf of the same size, which shows: a core rod_ 在 —starts from the fusion fabric Before the two cores are around... Brief description of the drawings: Optical fiber 10, 10 ', 10 " Optical fiber section 10A, 1〇β; Heart core 12, 12 f '14, 14', 14 '' Cardiac fan 14 &rigid; cladding. 16, 16 'central axis 18, 18'; central axis 18A, ⑽; score% light sugar ice light 30; core 32, 34, 36, 38; package Layer 40; heart 44; central axis post

454 09 9 '. A7 ___ B7 V. Description of the invention (7) Printed by the Industrial Standards Bureau of the Ministry of Economic Affairs of the Central Government Bureau of the Industrial Cooperatives Co., Ltd. 60; waveguide 62, 64; core 66; optical fiber 7q. Substrate π Optical fiber 80; heart 82, cladding 84; light thumb 86; center axis 88 v pre-strike 90; rod 92, heart 'solitary' wood? · Pieces 94, 96; glass dust 预; pre.event ίο . Glass rods 102,104; filled rods 106, 108; tube members 11; dust '112; rods 114; core rods 116, 118; preforms 12; packs ^^ 22; preforms 130; core rods Pieces 132,134; dust 136. Detailed description: The multi-core fiber 10 shown in FIG. 1A has a positive dispersion core 12 and a negative dispersion core 14 and is surrounded by a common cladding 1 cap. The two symbols of opposite sign dispersion, '12 and 14 ', refer to the central wavelength of a wavelength range (usually equivalent to the amplification window of the feedband), which is transmitted by the optical fiber 10. For the range from 530nm to 1560nm, the set core value can be similar to the SMF 1528 fiber, and the design negative core value can be similar to the product of 1585 LS. Two kinds of fiber can be provided by our company. For other wavelength ranges, different forms of known cardiac designs can be used, which are simply made as follows. : The rain bar is reduced by 1 parallel extension and separation of the heart fiber of the fiber optic school towel, and the distance from "S" can be adjusted to prevent or promote the automatic handle to fit between the heart cores 12 and 14. As shown in the figure, the distance " s " is assumed to be quite large enough to prevent automatic closing. In the manufacturing process, a core-bar member with a core-to-bar ratio of about 0.4 or greater is usually separated by a phase #sat to produce the required isolation. In the fiber 10 = additional nick 2 in the side (3 provides the reference point for the optical fiber 1 () angle index section length. In Figure 2 < the two initial section length continuity ship and 10B axis Ground alignment and relative rotation, the solution center axis hits ⑽ This paper is suitable for China and the country (please read the precautions on the back first and then fill out this page) • Binding-Thread 10 4 5 4 099 A7 B7 V. Description of the invention (g ·) Printed by the Central Consumers' Bureau of the Ministry of Economic Affairs, the Consumer Cooperatives of the Ministry of Economic Affairs ¾ Rotating before splicing together, it uses, for example, a splicer to design it as a polarized maintaining fiber. Choosing the size of the rotation will make fiber section 1 〇A's positive value 12A is aligned with the negative dispersion core 14B of the optical fiber section 10B. In addition, the design symmetry can also make the negative dispersion core 14A of the optical fiber section 10A and the optical fiber section 12B Positive dispersion center alignment 12B. The lengths of the segments 10A and 10B can be adjusted to differ from the combined length of the two segments 丨 0A and 〇β, and the average dispersion along any subsequent pair of segments Close to zero dispersion. Suppose that the two cores 12A, 14A and 12B in each segment 10A and 10B. 14B is used to transmit different signals. The positive and negative dispersion values of the two cores are the same and the two segments 10A and 10B should be equal in length. However, if there is only one cardiac transmission signal in each segment (For example, the heart core 12A of segment 10A and the heart core 14B of segment 1 〇B), the dispersion of the two cores can be optimized at different sizes and the segments of different lengths can be combined to obtain an average The dispersion is close to zero. The dispersion slopes of the two cores are preferentially matched to keep the average dispersion close to zero over the entire transmission wavelength range. Fibers without segmented lengths are spliced with alternating optical paths at positive and negative dispersion centers. Between cores 12 and 14, passive or active coupling can occur between the forward lengths of the cores 12 and 14. Passive coupling can reduce the separation between the cores " S11 so that the power transfer is centered on the required dispersion period The period between cores is equal to the coupling length. The positive and negative dispersion of cores 12 and 14 should be symmetrical to the central wavelength (which is equal in size), because the signal is occupied in each core. 12 and 14. Half-time. The propagation coefficients of the two cores 12 and 4 regarded as isolated should be as same as possible to maintain more complete power transfer. The coupling length is determined by the difference between the propagation coefficients of the two lowest-order supermodes of the composite waveguide. Paper size applies to China National Standards (CNS) to specifications (2 丨 〇 > < 297g) (锖 Read the precautions on the back before filling this page)-Gutter and can be designed as achromatic or light Figures 3A and 3B show the positive and negative dispersion of the refractive indices of the cores 12 and 14, respectively, and the difference is changed so that the effective refractive indices between the two cores 12 and 14 are equal. Positive The value dispersion core 12 has a simple step distribution (Ge〇2—

Si 〇2 core has Si 〇2 cladding) and effective refractive index "n (milk)" between the core and cladding value. Negative value dispersion core 丨 4 has "w form" or segmentation Mind: The third decoration is added, and the dopant with a slight increase in the refractive index of the cladding layer matches the positive refractive index of 12 effective refractive index " neff ". For example, the cladding containing the dopant can be made of Ge 〇2-Si〇2 or Ti〇2-SiO // f. (Note: the dashed line in Figure 3B represents the refractive index of the stone cladding layer 16.) Generally, more complex distribution shapes need to form negative dispersion and The dispersion slope is different from the case with positive dispersion cores. The other four examples are depicted in Figures 3C-3F. Each case can maintain negative dispersion without unduly compromising other optical characteristics such as effective area, mode field Diameter, bend, and microbend. The arrows that intersect the distribution line indicate the flexibility of the design to change the various line segments of the distribution. Use the distribution of Figure 3C to achieve positive or negative dispersion with a positive or negative dispersion slope. Figure 3D design Specially used as reaching with a considerable effective area Positive or negative dispersion. The latter two design diagrams 3 £ and 邡 can be considered as dispersion control, which has low loss during manufacture. Attention: Effective light coupling between 12 and 14 can be between the cores as shown in Figure 4. Is achieved by forming one or more long-period gratings 24. The coupling function is local, so the two cores 12 and 14 can be independently designed. For example, the propagation coefficients between the cores 12 and 14 and the core dispersion can be small. Change it. Grating 24 wooden paper ruler ^ TfSii standard (CNSy ^ M 210x-^^ y D4〇99 .A7 ~~ --- '' _B7 V. Description of the invention (P) 1 ΊΛ Member of the Central Bureau of the Ministry of Economic Affairs Two ίίίφί cooperation.,-Ϊ́-t .: The interval can be adjusted to compensate for the different sizes of cardioid dispersion, so the average value multiplied by the length is still close to zero dispersion. Gradual changes can be used and long-period gratings24 Coupling function for magnification.-The long-period grating 24 can be formed of a light-color sensitive core material, which is exposed to a chemical radiation pattern to create a scoring disturbance in the optical fiber 10. The cladding region between 14 and 14 can also be manufactured Optical scoring to improve coupling function. Long period light 24 can be marked by the high-power excimer laser during the drawing operation of the fiber. The dispersion period can be very small and various, because the coupling mechanism cannot add contaminants to the fiber 10. The accuracy of the grating is very strict because The required spectrum effect frequency band is a very common and long-period grating, which usually has a period of about several hundred microns. At the same time, the size of the scratch disturbance is very low (to avoid the need for hydrogen loading), because the long-period grating 24 will run along the fiber 10. Occupies a considerable distance (for example, one or two meters) without negative effects. Scale disturbances can mark one point at a time or immediately count the number, especially at the height pull speed. The scoring or curvature disturbance can also be marked with a high-power CO2 laser during the drawing operation to accomplish a similar coupling function. The ability to use other perturbations to form similar gratings includes pressure changes generated by periodically extruding fiber or path length changes or by periodic microbend path length changes. Other information about long period gratings and die face combiners can be found in Long-Period Fiber Gratings, as Band-Rejection Filters by VengSarkar, published in Journal of Ligthwave Technology, Vol, 14, No. 1, JanuaiT 1996, pages 58-65. Medium, and Pohl and others, " HelicaJL-Grating Two-Mode Fiber Spatial-Mode ★ The paper size is applicable to China National Standards (..CNS) to present (2 丨 0 > < 297 mm) 13 '(Please read the precautions on the back before filling this page).

, 1T 454099, 'A7 —--; --B7 V. Description of the invention (丨 丨) 2 1 Printed by the Central Government of the Ministry of Economic Affairs ^ Printed by Bei Gong Consumer Goods Couple: r Also published in Joumal _〇 f Ligthwave Technology, '_〇 * 5, May 1991, pages .. 598-604 literature. Two articles are included here for reference. ; More than two cores can be formed in a single fiber, as shown in Figure 5. The two positive dispersion cores 32 and 34 and the two negative dispersion cores 36 and 38 of the optical fiber can be surrounded by a common cladding. Cortex 32-38 can be paired with positive and negative dispersive cortex groups (for example, 32, 36 and 34, 38), and the paired cortex can be optimized for individual bit rates or applications. It can be changed, and the pairing can be changed by changing the angle between adjacent sections of the optical fiber 30 to increase the flexibility of the dispersion plan. In other words, the same fiber 30 can be used to maintain-set multiple different dispersion plans. The virtual core 44 provides a reference point for optically marking the optical fiber 30 around the optical central axis 46. Similar to the cores 12 and 14 of the optical fiber 10, and the cores 32, 34, 36, and 38 of the optical fiber 30 are offset, and the money generates a prototype color problem. This problem can be reduced by periodically twisting or continuously chirping the fiber 10 or 30. The cores 12 and 14 of the optical fiber 10 or the cores 32, 34, 36, and 38 of the optical fiber 30 can be surrounded by respective cladding regions to optimize the separation optical path performance through the optical fibers 10 and 30. When connected to a conventional single-mode fiber or similar waveguide structure, such as an instant amplifier workstation or a connection end, each pair of two cores is a single core of a conventional waveguide. Figure 6 depicts a gradual coupling region 60, which connects the dispersion management fiber 10 to a conventional single-mode fiber 70. The two waveguides 62 and 64 are aligned with the positive and negative dispersion cores 12 and 14 of the optical fiber 10, but only the waveguide 64 is aligned with the single core 66 of the conventional optical fiber 70. Within the consumable area, two waveguides of 62 paper sizes are applicable to the Chinese storehouse standard (CNS) six 4 specifications (2 丨 0X 297 public fee) \ ψ I --------- install-(Please read first Note from the back, please fill out this page), 1T line 4 5 4 09 9 A7 B7

V. Description of the invention (tJ and 64 are gradually coupled together to transfer power to the waveguide. A long-period grating 24 can be used instead of the gradual light closing region 60. As shown in the figure? To guide the optical signal into the appropriate heart (For example, the core core 12) Before the interface of the traditional optical fiber 70. The core core 66 of the conventional optical fiber 70 is aligned with the core fusion wire of the dispersion management optical fiber 10 and the optical fiber spreads along the fresh fiber. The V-groove substrate 72 is maintained The required alignment between the optical fiber 10 and 70. ^ Traditional Guang Qing Nozaki hybrid dispersion management light, _Heart, core 12 or 14 'or the traditional rule that each twelve and 14 can touch the separation. In the latter f month In this case, the optical fiber switcher (not shown) can be used to alternately connect the traditional optical fibers to the single-traditional Lai. The switcher can be controlled by the sensor. Figure W depicts another optical fiber 10, which has two similar cores 12, and 1 'buried under the common cladding. Compared with the core of fiber 10 (not shown in the figure) (Middle), the core of the heart is along the center of the optical axis of the other Guangqing, the other core is 14, The central axis 18, ^ The central core 12 is easier to align with the core of the standard fiber. However, the segments are alternated, and the end of the fiber 10 'is facing the end to splice to offset the central core 12 and deviate ~ It is more difficult to condense the signal of the 14th. Therefore, the heart cores 12 and 14 and the second of the 2nd turn f are preferentially laterally-occurring. Before any end is connected to the end, Yeyou Silk will gradually change first. _ 'Or by gradually shifting it to _ offset to the center minus 12, as shown in _. __Asian concentration has only one stamen 12, on the optical central axis 18, Figure 1C shows that the other has Two cores 12 "and 14" fiber 10 "are set in the center of the optical fiber in a concentric circle pattern. The side face coupler can be used to offset

ir 4 5 4 09 9 V. Invention_

.14. The Ministry of Economic Affairs rb ordered A's ^ to fool between the concentric cores 121 'and 14 ". Optical fiber 10 with concentric cores 12 "and 14 " shows a smaller birefringence and is easier to manufacture with traditional techniques. It is also possible to use other concentric cores or concentric cores that merge with off-center cores .. In fiber Another method for medium dispersion management is depicted in Figure 8. The shown multimode fiber 80 has a center core 82 and a cladding material surrounding it designed to maintain greater than one silk pass though. For example, a basic mode Showing positive value dispersion; and in addition, for example, showing negative value dispersion for the second-order mode. The long-period grating 86 is marked on the optical fiber 80 in a repeating pattern along the optical center axis 88 'This pattern adjusts the optical in each mode The sum of the signal's relative durability and the average dispersion product is close to zero. &Quot; Referring to Figure 8, the second-order mode negative value dispersion has a larger value and is larger than the negative value of the fundamental mode. Therefore, the running distance between the gratings 86 in the fundamental mode is measured The distance between the lengths LF is greater than the running distance between the gratings 86 in the second-order mode. The other distances are possible, including the opposite sign of the same size between the two operating modes, and the dispersion. Equally spaced light can be used. In order to evenly distribute the optical running distance between two non-drags. At the same time, a die higher than the second mode can be used for this purpose to reduce chirp and polar mode dispersion. Grating ridge height offset 1 «moved to 仏Continuing higher-order modes, but the unpredicted and expected loss pairs for adding modes will limit the use of higher-order modes. Figures 8 and 9 plot the performance with a step index. In Figure 8, the normalized propagation coefficient 'The benchmarking frequency V " is drawn, and it can be defined mathematically as follows: bnK / 5 / k-n2) / (n 「n2) Please read the notes on the back first # fill in this education]-equipment · line 4 d 4 uy y M B7 5 1—_ 5. Description of the invention (leaf) τ.!? i 消

i'J V 2 2; τ—2-η22) 0 · 55 / λ where " point " is the propagation coefficient, X 'is the refractive index of the core,' v is the refractive index of the cladding, and " is The central wavelength of a range, and " k "is the coefficient 2ττ / λ, and " a " is the core radius of the waveguide. The normalized propagation coefficient is expressed as " n (eff > ", which is in " 〇 " And 111 ", " 〇 " means the entire spread in the cladding and" Γ means the entire spread in the heart core. More transmission in the heart core is more strictly restricted than in the cladding. The normalized frequency value "V1 'has an inverse relationship with the central wavelength " λ ". The curves LPq !, LPU, and LP02 represent the fundamental mode, the second, and the third mode, respectively. According to the exemplary curve diagram of FIG. 9, a normalized frequency greater than 2.4 is required to maintain a mode, but a large value even around 3.5 is required to properly define the most commonly used signals. As shown in Figure 10, about 3.5 standardized frequencies An operating area is also provided, which has the opposite sign to the normalized waveguide dispersion " Dn 11 Its empirical formula is as follows: Dn = Vd2Vbn / (dV2) Although less than 3.5 normalized frequency may produce higher dispersion, the second-order mode signal limit will be reduced. Operations far away from the second-order mode cutoff wavelength (that is obviously high) 4) will reduce bending and bending loss and polarization splitting. Periodic or continuous twisting of optical fiber 80 can also be used to reduce polarization mode dispersion. Waveguide dispersion measured in ps / km " D " Dn (-niA) / (cA) can be calculated by the following formula, where △ is the relative refractive index difference. The waveguide dispersion " D " sign is opposite to the normalized waveguide dispersion "Dn", so the fundamental mode "LPqi" waveguide dispersion is positive And the 1st paper standard is applicable in the first paper standard (CNS) / \ 4 present grid (21〇_X 297 public capital) 1 * 7 ... (Please read the precautions on the back before filling this page). Order line 4 54 09 9 、 Instruction of the invention (\ f) A7 B7 6 1 Combined second-order mode. LPn " Waveguide dispersion is negative. At a standardized frequency greater than 2.4, the waveguide of the fundamental mode Lp θΐ of the step-index fiber Dispersion "D " is quite low so any significant light dispersion is mainly attributed to Material dispersion. In the 1550nm frequency window, the fundamental mode dispersion of a step-index fiber is limited to 17-20ps / km. However, more complex stamen distribution designs that include segmented stamens and annular distribution can be used Produces higher dispersion values. The core design between positive and negative dispersion cores can also be selected to properly correlate the dispersion slope so that the average dispersion remains near zero over the entire signal wavelength range. For example, the dispersion slopes are equal in magnitude, but the signs are reversed or the absolute value is low. Multimode and multicore designs can be incorporated into each fiber to further control dispersion, while other design criteria are optimized. For example, the cores 12 and 14 of the optical fiber 10 depicted in Figure 1A or the other cores depicted in Figures ΐβ and π can be formed into multimode cores, and the dispersion specifications can be distinguished between the modes and the cores. 'Member & can use conventional manufacturing techniques to make multimode fiber 80, and light refraction techniques similar to those previously described for multicore fibers can be used to mark gratings. Although the long-period grating 86 preferentially acts as a mode coupling to other patterns and variations including diameter changes, it can also be used to bias signals between different modes. The remaining Figures 11-14 show various prefabricated parts (also known as bristles) to make it easier to manufacture the previously described multicore fiber, which uses different rods in the tube 'and to form an OVD (optical vapor Phase deposition) technology. The optical fiber preform 90 shown in FIG. 11 has a drilled rod member 92 to support the two (please read the precautions on the back before filling this page.)

、 1T line—— 454099 A7 "-----. _ B7 V. Description of the invention (() glass heart loyalty 'rods 94 and 96. The rod 92 is made of cladding material, and two glass pot cores The rods 94 and 96 include a core and a cladding material, which are sequentially coated by optical vapor deposition to produce refractive index distributions with different dispersion characteristics. Glass dust 98 is also manufactured from the cladding material and coated on The outside of the rod is consolidated to complete the preform 90. The multi-core fiber drawn from the preform has at least two cores extending parallel to each other and exhibits different scattering characteristics. The optical fiber preform shown in Figure 11 100 has two glass rods 102 and 104, two filling rods 106 and 108 installed in the tube 110, and a consolidation dust 112 surrounding the tube i1G. The two heart cores take And 104 have core and cladding distributions, which maintain different dispersion characteristics. Filled rods 106 and 108, f 11 and dust H2 are all made of cladding material, which is related to the core rod 102 and 104 is fused together to complete the preform. ^ Figure 12 depicts the preform 120, which contains a special shape Rod-like cladding member 114, which maintains two core members 6 and 118 with different dispersion characteristics. The two core members 16 and 118 can be adhered to the rod 114 to maintain the two core members. The rods continue to be fixed at the required relative position until the preform 12o is consolidated. As shown in FIG. 13, the preform 13o contains two core rods 132 and 134 adhered together and is surrounded by consolidation dust 136. Cardiac rods] [32 and 134 have different dispersion characteristics and refractive index distributions, which can promote or prevent the automatic coupling between the final cores drawn from the preform 130. Dust coating 98'112, 122, And 136 shrink in the axial and radial forces during the consolidation process, and its sealing components are in the prefab 90, 100, 120, and the paper is very suitable for IS, ¾ Jia Cupquan (CNS) 210X2 ^ ^ 7 4 Λ7 Β7 8 It · V. Description of the invention (Η130). In the next drawing process, there is co-operation between the heart and the heart, and refraction technology can be used to compensate the heart around the heart, and to supplement one side, The considerable amount is set to generate the Xiao Niu reference point. 赖 In the four faces, Lai Xinrui leans _96, wins 1 {} 4, ιΐ6—, and 132-134 with Yang et al. or unequal absolute numbers = size or dispersion of continuity or continuity. The length and average dispersion product are close to zero. However, different sizes of dispersion are required, and the period is full. In different dispersive cores, different operations are performed to achieve the relevant long-term flat peach blossoms.. '' ~ ..... ---- 1 n I— n ----- I-·! --- ( Please read it first. Read the precautions on the back before filling out this page} --- Order --- 1 Line 乂 乂 乂. ) National Standards of 7 Countries (CNS) Λ4 is now available (210 X 297 public epidemic) * 2 ^ 0

Claims (1)

4 54 09 9 9 1ί. A8 B8 C8 D8 6. Scope of Patent Application Central Bureau 1. — A multi-core optical fiber for managing light dispersion, including: — a group of multiple cores surrounded by a cladding; the multi-core has a cladding having a refractive index different from that of the optical signal transmitted Refractive index; and 'The multiple cores exhibit excellent dispersion between the cores. 2. According to the optical fiber of item 1 of the scope of patent application, one of the cores has a chromatic dispersion value and the other core has a negative dispersion. 3. The optical fiber according to item 2 of the scope of the patent application, in which multiple core tombs exhibit standing values and negative dispersion slopes. 4. The optical fiber according to item 2 of the scope of patent application, in which the positive and negative dispersion values are symmetrical to the central wavelength of the optical signal. 5. The optical fiber according to item 4 of the scope of the patent application, in which multiple cores are placed quite close together to maintain coupling between multiple cores. 6. The optical fiber according to item 5 of the scope of patent application, in which the propagation coefficients between the cores are approximately equal. 7. According to the optical fiber in the scope of patent application, one of the cores is a multimode core. 8_ The optical fiber according to item 7 of the scope of the patent application, wherein the multimode core includes a first mode in which I exhibits positive dispersion and a second mode in which it exhibits negative dispersion. 9. The optical fiber according to item 1 of the scope of patent application, in which the multiple cores are separated far enough to prevent coupling between the cores. 10. The optical fiber according to item 9 of the scope of the patent application, wherein the optical fiber also includes a gradation part to promote the transfer of the optical signal between the heart cores. 11. The optical fiber according to item 9 of the scope of the patent application, in which the core formed in the heart core, or the legal scale is applicable to the Chinese country. CNS (2) 0X297 mm) Guang Chu read and wept Fill in the contents of this tribute)-Packing. 4 54 09 9 < B, CD 20 VI. Patent Application Scope Central Ministry of Economic Affairs " Bureau staff extinction co-operative printing disturbance will promote the transfer of optical signals between the heart. 12. The optical fiber according to item π of the scope of patent application, wherein the disturbance is also formed in the cladding region between the cores to facilitate the coupling between the cores. 13. The optical fiber according to item 1 of the scope of the patent application, wherein the perturbation arrangement will form a group of multiple gratings to transfer optical power between the cores. 14. The optical fiber according to item 11 of the scope of the patent application, wherein the perturbation arrangement pattern will shift the optical § hole number between the cores, and the product of its length and average dispersion will be close to zero at the central wavelength of the optical number. Π 15. The optical fiber according to item 11 of the scope of the patent application, wherein the optical fiber gradient section and the perturbation are used to promote the transfer of the optical signal between the heart cores. Person 16. The optical fiber according to item 丨 of the scope of the patent application, wherein the optical fiber is divided into two £ ·! Also, the counterparts are rotated relative to each other and spliced together as relative rotary contacts ^ to align the first pair with different dispersion Worth of heart. π 17. The fiber according to item 16 of the scope of the patent application, in which two segments of fiber can be rotated towards another angular position to align the second pair of fibers with different dispersion values. 18. The fiber according to item 17 of the patent application, wherein the first paired core cage is optimized for the first bit rate and the second paired core is optimized for the second bit rate. Ά 19. The optical fiber according to item 丨 of the scope of patent application, which further includes an optical fiber interface to connect a heart-wrath which is not located in the center of the cladding to the core of the additional optical fiber located in the cladding. A 20. The optical fiber according to item 1 of the scope of patent application, in which the optical fiber is turned at least periodically to avoid polar mode dispersion. This paper size is applicable to Zhongwei National Standards (CNS) Λ4 See the grid (210X 297 mm) (Please read the precautions on the back before filling out this page} 、 1T line 9 9 ο 4 5 4 ABCD patent application scopeΊί 2 4i Φ • ΐ ·. 宍 局 • r- " Second, Consumer 21. According to the scope of the patent application. Item 1 'of the fiber, which further includes a light closing mechanism, which transfers the optical signal to the forward part of the heart, making First learn that the product of the length and average dispersion at the central wavelength of the band is close to zero. · 22. According to the optical fiber of item 21 of the patent application, the center core of the optical fiber exhibits excellent gas slopes that match the length and flatness within a wavelength range of the optical signal ^ The dispersion product is close to zero. 23. A multimode fiber that manages light dispersion, which includes:-a core is surrounded by a cladding to keep light in multimode transmission along the optical central axis; and the first mode path follows An optical central axis having a first dispersion value; a second mode path along the optical central axis having a second dispersion value;-the first and second dispersion values are different from each other; and a set of multiple mode couplers along the optical The mandrel couples light back and forth between the first and second mode paths. 24. The optical fiber according to item 23 of the patent application scope, wherein the first mode path is a fundamental mode path with a positive dispersion value. _ 25. Basis The optical fiber of the 24th scope of the patent application, wherein the second mode path is a fundamental mode path with a negative dispersion value. &Quot; "~, 26. The optical fiber according to the 23rd scope of the patent application, wherein the first and second mode paths The inter-dispersion values have opposite signs and unequal absolute values. 27: The optical fiber according to item 26 of the scope of the patent application, in which the inter-light rays of the first and second mode paths occur at different lengths of the non-tree path. The absolute value is compensated. 28. The optical fiber according to item 23 of the scope of patent application, in which the first and second mold paths (please read the precautions on the back before filling in this page). Install two 11 wires " This paper size applies Ten countries trapped family # 准 （CNS） 八四 格格 (210X297 mm) 4 454099 ABCD 2 2 VI. Patent Application Park — Inter-path dispersion values have opposite signs and are approximately equal in size. 29, | According to the first fiber of the scope of application for patent 23, the mode coupler is formed by the disturbance of the score. '30. The optical fiber according to item 29 of the scope of application for profit, wherein the scoring disturbance forms a long-period grating. Λ-31.j is an optical fiber according to item 23 of the patent application range, in which the mode coupler is formed at least in part by a graded portion of the optical fiber. 32. The optical fiber according to item 23 of the scope of the patent application, wherein the mode coupler is placed so that the solution color uniform product is close to zero in the length of the transmission gauge. 33. According to the phosgene of Item 32 of the scope of the patent application—and the second mode path shows excellent dispersion slopes that match the length and the average dispersion product within a wavelength range of transmitted light close to zero. 34. — Dispersion compensation fiber optics A system comprising: a first multi-core optical fiber section having a first optical fiber exhibiting a positive dispersion value and a second optical fiber exhibiting a negative dispersion value; a second multi-core optical fiber section having a positive dispersion value Value of the first fiber and the second fiber exhibiting a negative dispersion value; ^ The optical interface between the first and second multi-core fiber sections converts the first-core section of the first fiber section and the second fiber section The second core of the segment is aligned to control the average dispersion along the combined length of the fiber segment. ° 35. The optical system according to item 34 of the patent application scope, wherein each of the first and second fiber segments is the first And the second core are sufficiently separated to avoid unwanted coupling between the first and second cores. ~ 36. The optical system according to item 34 of the scope of patent application, in which the wood fiber scale of the fiber zone is applicable China® National Standards (CNS) Λ #! Grid (210x: 297 public goods) In In II si 1 II--mi; ^ i—I (please read the precautions on the back before filling this page), line 11: ABCD 45409 9 The second core is aligned with the first core of the second fiber segment to control the average dispersion. * * 37. The optical system according to item 34 of the patent application scope, wherein the second core of the first fiber segment and the first core The first core of the two fiber sections exhibits a dispersion slope matching so that the average dispersion along the combined length of the fiber section within a transmission wavelength range of the transmission through the merged fiber section is close to zero. Optical system, in which the first and second night coagulation fiber sections also have a third core, which has a positive dispersion value, and a fourth core, which has a negative dispersion value. 38 items of winter optical system, in which the first core of the first optical fiber segment is aligned with the second core of the second optical fiber segment to complete the optical path between these segments under the optimization of the first bit rate transmission and Third heart of the first fiber segment The fourth core aligned with the second optical fiber section transmits the optical signal at the second bit rate. 110-40. According to the optical button of the project, the first and third of the optical fiber section The peak division and the + standard of the second optical fiber section to generate different optical trees of the p 4 range of the optical fiber, the fourth optical fiber system, in which the first optical fiber area and the second core and core are also separately with the second The fourth core alignment of the optical fiber section produces more options for dispersion compensation. I ^ ^ The optical system of item 34 of the patent scope emits the light required for the angular notch applied to the optical fiber secondary aid at the optical interface. Shenchenli is currently covering the optical system of item 34, in which the connector for the design of the optical fiber for holding the polarized pole 454 09 9 Λ8 B8 C8 D8 24 will produce the required optical interface. 44. The optical system according to item 34 of the patent application, wherein the first and second optical fiber sections are substantially the same sections produced from the same optical fiber. 45. A dispersion-compensated fiber optic system comprising: a multimode fiber, which has fundamental mode paths and higher order mode paths of different dispersion values, a group of multiple mode couplers shifted back and forth along the central axis of the fiber optics The optical signal is between the fundamental mode and the higher-order mode path; the optical system components are aligned with the optical central axis of the fiber to further transmit the optical signal; and the mode coupler is arranged to guide the optical signal into a mode path between the system and the system. Interface of the component. '46. The optical system according to item 45 of the patent application, wherein the fundamental mode path has a positive dispersion value and the higher order mode path has a negative dispersion value. 47. The optical system according to item 46 of the patent application, wherein the negative dispersion value has a higher value than the positive dispersion value. The optical system according to Item 47 of the scope of patent application, wherein the mode coupler shifts the optical signal between the mode path and the higher-order wedge path at unequal distances between the mode branches. : According to the 45th patent application of the optical system, one mode is coupled to the optical mode, and the fundamental mode path precedes the optical system components. The optical system according to item 45 of the patent application scope, wherein the optical system group ^ an optical amplifier and a mode coupler guide the optical signal into a higher path to connect the optical amplifier. (Please read the precautions on the back before filling in this page). Binding and binding line 4 54 09 9 Λ8 Β8 C8 D8 51. The optical system according to item 45 of the scope of patent application, perturbation along the scale of the optical center axis to transfer optics 52.-A dispersion compensation fiber optical system, which includes:-a single fiber in which the mode coupler packs the signal between the mode paths It has a set of multiple optical paths with different colors to transmit optical signals; the continuity of the political characteristics at the central wavelength of the optical signal-the optical path has a positive dispersion. At the central wavelength of the optical signal, the path is bound. For example, the dispersion mechanism of chaos value shifts the optical signal between the first and second slit months, and the length and the average dispersion product are close to love at the wavelength of the optical signal center. 53. The optical system according to item 52 of the application, wherein the first and second paths extend parallel to each other and the coupling mechanism shifts the optical signal between the parallel portions of the first and second paths. 54. The optical system according to item 53 of the scope of patent application, wherein the first and second optical paths are formed by the first and second cores hidden by the cladding. 55. The optical system according to item 54 of the patent application, wherein a single optical fiber has a central central axis and the first core is aligned with the central central axis and the second core is offset from the central central axis. Jiyang 56. The optical system according to item 54 of the patent application, wherein a single optical fiber has a central center axis and the first and second cores deviate from the central center axis. ^ 57. The optical system according to item 54 of the patent application, wherein The first core is a multi-mode core with a first mode showing positive dispersion and a second mode with a negative dispersion. 58. The optical system according to item 54 of the patent application, wherein the coupling mechanism includes a set of multiple couplers that positively shift the optical signal back and forth in the first paper scale application (CNS) (210 X 297 / ^ ¾) Application for patents "Park Λ8 B8 C8 D8 26 ^ 容. &Quot; '..' ?? &" ^-,-'汽 ντ'η: ΐ.' '. Λ: Γ 工 r and the second Between the heart. '59. The optical system according to item 58 of the scope of patent application, in which the first and second cores show opposite signs of different sizes at the central wavelength of the optical signal. ^ The dispersion and the arrangement of the couplers shift the signal at different intervals to the first — Between the second heart. ~ ^ 60. The identification system according to item 54 of the scope of patent application, in which the light closing mechanism is formed because the heart is placed very close to it to keep the optical signal transferred between the heart. 61. The optical system according to item 1 of the scope of patent application, in which the first and second cores exhibit the same size and opposite dispersion at the central wavelength τ of the optical signal towel. 62. The optical system according to item 52 of the scope of patent application, wherein the first and second optical paths extend concentrically with each other and the coupling mechanism is offset between the first and second path_central circle portions. ^ Xian 63. The optical system according to item 62 of the scope of the patent application, in which a single fiber is a multimode fiber and the first and second optical paths have a mode path and a higher order mode path with different dispersion values. Soil 64. The optical system according to item 63 of the patent application scope, in which the handle mechanism includes a set of multi-faceted Mi, and its recording material is reduced between the path of the basic mode and the higher mode. 65. The optical system according to item 63 of the scope of the patent application, in which the first and second cores and cores have a relatively large and small dispersion when the optical signal is long. 66. According to the application of the optical system of UJ Item 52, the middle-aged mechanism can be read first. Please read back the V6 crying note rt and fill in this education) —I ---. 丁 _ 、 I --- -! This paper & scale is applicable (C ^ A4 ^ (210 ^^ 7 ^ 54099 six ',, patent application scope ABCD 27 Formed by perturbation in the optical path. An optical system according to claim 66, wherein the coupling mechanism includes a set of multiple gratings. 68. The optical system according to item 52 of the patent application, wherein the third and fourth optical paths have different dispersion characteristics to transmit optical signals. 69. The optical system according to item 52 of the application, wherein the coupling mechanism includes the coupler shifting the optical signal between the first and second paths with a first dispersion period and the coupler shifting the optical signal with a second dispersion period between Between the third and fourth paths. 70. According to the optical system of claim 52, the first optical path exhibits a positive dispersion slope and the second optical path exhibits a negative dispersion slope. 71. The optical system according to item 52 of Shenyan's patent, wherein the first and second optical paths exhibit excellent scatter slopes close to zero. 72 · —A method for manufacturing a multi-core fiber to transmit an optical signal with reduced light dispersion, the method includes the following steps: Align at least two glass core rods, the refractive index distributions of which are different from each other; Layer material surrounds the glass core rod member; fuses the cladding material to the core core rod member to form a glass preform; and pulls out the multi-core fiber from the at least two core core preforms, which extend out of each other and present Out of different dispersion characteristics. 73. The method according to item 72 of the scope of patent application, wherein at the central wavelength of the optical signal, the first core has a positive dispersion and the second core has a negative value -------------- (Please read the precautions on the back before filling in this page. Order-Thread --- m-1 HI The paper size is suitable for Chinese EJ homes # PD (CNS) (210 × 297 ^ ~ Τ 28 28454 09 ^ Dispersion. The method of claim 2 is the method of claiming patent: the capping step includes coating the cladding material with optical dust 75. The method according to item No. 2 of the application scope, wherein the step of aligning includes aligning the free strips to the pieces For face rods, the refractive index is similar to that of the outer cladding material. m The method according to item 75 of the scope of patent application, in which the glass rod member supports two heart-shaped rod members. 77. The method according to item 72 of the scope of patent application, which further includes the step of arranging the two core rods around the front axis with a glass cladding. 78_ The method according to item 72 of the scope of patent application, which further includes forming a coupling between the two stamens. 79. The method according to item 72 of the scope of patent application, which further comprises the step of coating the scale s to generate a sharp reference point on the optical fiber. 80. A method for compensating light dispersion. The dispersion is added to the optical ifL number propagating along the fiber. The method includes the following steps. • Guide the signal along the fiber, which is arranged to have the opposite sign at the center wavelength of the signal. Dispersion characteristics of the two parallel optical paths; and the coupling signal back and forth between the continuous parts of the two parallel paths of the optical fiber so that the average dispersion of the illumination signal is close to zero dispersion. δΐ, according to the method in the scope of patent application No. 80, wherein the light closing step includes shifting the signal between different cores of the multi-core fiber. Pyridium is a method based on the details of the scope of the patent application, wherein the light closing step includes shifting the signal between different modes of the multicore fiber. (Please read the precautions before filling in this page) Install I .-- ° line α scale pass; Π Zhongyuan National Standard (CNS) 8 4 condition (21 〇X tear off) 4 54 09 9 6 、 Fan for patent application | δ3. According to the value of the square w of the patent application scope, the distance between the paths is unequal. , And the light and light step-by-step job includes the scope of the patent of the scope of the patent according to the standard; Columns are parallel to pass rounds for the same amount of time and money numbers are combined with the Buhui package. The paper method is a good standard ® National Standard (CNS) Λ specifications (210 parents 297 male ^ :)