CN104076433B - A kind of fiber mode separator - Google Patents
A kind of fiber mode separator Download PDFInfo
- Publication number
- CN104076433B CN104076433B CN201310692492.0A CN201310692492A CN104076433B CN 104076433 B CN104076433 B CN 104076433B CN 201310692492 A CN201310692492 A CN 201310692492A CN 104076433 B CN104076433 B CN 104076433B
- Authority
- CN
- China
- Prior art keywords
- core
- fibre
- fiber
- fibre core
- mode
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Active
Links
Abstract
The present invention discloses a kind of fiber mode separator, and optical fiber is made up of host material and three fibre cores；In line, middle fiber core is identical with the centre distance of both sides fibre core for three lines of centres of fibre core.Three index distributions of fibre core, core sizes are identical.The present invention using three fibre cores optical fiber structures, the coupling length difference between increase different mode, implementation pattern efficiently separates, and mixed effectively between suppression mode disturbs.Used after being concatenated, be capable of achieving to efficiently separate multiple different modes.Fiber core parameter is identical, it is to avoid during using different size fibre core, the difficult and influence of the parameter error to fiber coupling performance of making.
Description
Technical field
The present invention relates to fiber optic communication field, it is specifically divided into the mode splitter between implementation pattern separate.
Background technology
In recent years, space division multiplexing causes the extensive interest of people.SDM system uses multi-core fiber or multimode light
Fibre is realized.It is by different mode when wherein using multimode fibre（Including different polarization modes）Realize mode division multiplexing.Due to
The different information of multiple different pattern load, therefore, mode division multiplexing can effectively improve the transmission capacity of optical fiber.
In mode division multiplexing system, both needed for different mode to be synthesized to an optical fiber, it is also desirable in receiving terminal by difference
Pattern efficiently separated.Pattern bundling device is needed in transmitting terminal, and mode splitter is needed in receiving terminal.Using point
Vertical element, such as grating with the separation of implementation pattern, but can increased the complexity of system.Mode splitter based on optical fiber structure
Most simple case be Twin-Core Fiber Coupler using symmetrical structure, using the difference of different mode coupling length, by choosing
Select the purpose that suitable parameter with implementation pattern can just separate.Because the coupling length of different mode to be made meets specific multiple
Relation, the narrower bandwidth of the separator that this method is obtained.It is same with the twin-core fiber that less fundamental mode optical fibre is coupled based on single-mode fiber
Also can be used as pattern bundling device, the basic mode that it has the disadvantage single-mode fiber is based on index matching with the high-order mode of less fundamental mode optical fibre
Coupling, due to being difficult to Broadband Matching, its bandwidth of operation is general all narrower, and can be coupled between different mode【Few-
(less fundamental mode optical fibre is used for mode division multiplexing to mode optical fiber for mode-division multiplexing）,Opt. Fiber Technol.,2011, 17(5): 490-494】。
The content of the invention
In view of the shortcomings of the prior art, there is wideband operation characteristic it is an object of the invention to provide one kind and pattern is prevented effectively from
Between couple new ant algorithms separator.
The technical scheme is that：A kind of fiber mode separator, including three fibre cores and covering, the covering have base
Material is constituted；In line, middle fiber core is identical with the centre distance of both sides fibre core, institute for the line of centres of three fibre cores
The index distribution of stating three fibre cores is identical, three fibre cores diameters are identical, the normalized frequency of three fibre coresVIt is full
FootV>2.405,, whereinaIt is fiber core radius, λ is operation wavelength,n coreIt is fiber core refractive index,n cladFor
Cladding index.
As a further improvement on the present invention, the refractive index of three fibre coresaWith the refractive index of coveringn cladDifference expire
Foot：n core-n clad>0.008。
As a further improvement on the present invention, the centre distance of the middle fiber core and both sides fibre coredMeet：d >2a+3
μm。
As a further improvement on the present invention, the refractive index of three fibre coresaWith the refractive index of coveringn cladDifference expire
Foot：n core-n clad>0.01, the normalized frequency of the fibre coreVMeetV>3.832。
Technique effect of the invention is：Using three optical fiber structures of fibre core, the coupling length between increase different mode
Difference, implementation pattern is efficiently separated, and mixed effectively between suppression mode disturbs.Used after being concatenated, be capable of achieving to multiple not
With efficiently separating for pattern.Fiber core parameter is identical, it is to avoid during using different size fibre core, the difficulty and ginseng of making
Influence of the number error to fiber coupling performance.
Brief description of the drawings
Fig. 1 is a kind of cross-sectional view of embodiment of the invention；
Fig. 2 is the connecting curve of different mode in twin-core fiber；
Fig. 3 is the connecting curve of different mode in the optical fiber shown in Fig. 1；
Fig. 4 be Fig. 1 shown in optical fiber in from the first fibre core 2 be input into LP02After mould, the optical fiber at different transmission ranges
Field strength distribution；
Fig. 5 is that structure shown in Fig. 1 is used to separate LP02During mould, the output energy of the 3rd fibre core 4 is with wavelength change curve；
When Fig. 6 is normalized frequency V=4.8, d=18 μm of core centre spacing, a) it is for fibre core is poor with cladding index
The connecting curve of 0.01 different mode；B) it is fibre core and the connecting curve that cladding index difference is 0.012 different mode.
Wherein, 1 host material, 2. the first fibre core, 3. the second fibre core, 4. the 3rd fibre core.
Specific embodiment
The cross section that Fig. 1 show optical fiber of the present invention is illustrated, including host material 1, the first fibre core 2, the second fibre core 3 and the
Three fibre cores 4, in line, the second fibre core 3 is fine with first respectively for the first fibre core 2, the second fibre core 3 and the line of centres of the 3rd fibre core 4
Core 2 is identical with the centre distance of the 3rd fibre core 4.Index distribution, the fibre core of the first fibre core 2, the second fibre core 3 and the 3rd fibre core 4
Size is identical.Three normalized frequencies of fibre coreVMeetV>2.405.Here,, whereinaIt is fiber core radius, λ
It is operation wavelength,n coreIt is fiber core refractive index,n cladIt is cladding index.
If input light only includes both of which, i.e. basic mode and a high-order mode, then light beam is input into from the first fibre core 2, high-order
After mould is coupled, exported from the 3rd fibre core 4, basic mode is retained in the first fibre core 2, so that the purpose that implementation pattern is separate.If input
Comprising multiple patterns, then after light is input into from the first fibre core 2, pattern (the most short pattern of coupling length of most high-order in light）Will be from
Three fibre cores 4 are exported, and other patterns stay in the first fibre core 2.If desired all patterns are separated, then can be from the first fibre
The light of the output of core 2 isolates next high-order mode again through mode splitter.Finally all patterns can all be separated through separating for several times
Open.
In theory, using symmetrical twin-core fiber can also implementation pattern separate function.Had based on different mode
Different coupling lengths, selects suitable optical fiber parameter, and different patterns can be made to be exported from different fibre cores, so as to realize point
The purpose of beam.Fig. 2 for twin-core fiber different mode connecting curve, will light from side fibre core be input into when, opposite side fibre core
In mode of energy with transmission range change curve.As seen from the figure, optical fiber basic mode coupling length is most long, and mode order is got over
Height, its coupling length is shorter, such as LP02The coupling length of mould is longer than LP11Mould.Order pattern high is easier coupling, therefore coupling
The reason for length is shorter be：Order pattern higher its mode distributions more extend to covering, by theory of fiber, the weight between pattern
Folded region is bigger, and its coefficient of coup is bigger, therefore, its coupling length is also shorter.
If LP02The coupling length of mould is significantly shorter than LP11Mould, it is clear that LP11The coupling length of mould is shorter than LP01Mould.Therefore, take
Fiber lengths are LP02The coupling length of mould, then, if containing LP01Mould, LP11Mould, LP02The light beam of mould is input into from a fibre core, then LP02
Mould will be exported from another fibre core, and LP01Mould, LP11Mould is long due to coupling length, energy still input fibre core in, thus, just
LP can be realized02The separation of mould.If the coupling length difference between pattern is not big enough, easily there is the mixing between pattern, make
The crosstalk increase of output mode, so as to influence the extraction and reduction of information.For example, LP shown in Fig. 201Mould, LP11Mould, LP02Mould,
LP21Coupling length ratio between mould is：12.25: 2.04: 1.14: 1.The difference of three kinds of wavelength is smaller afterwards.
Obviously, the fibre core is non-single-mode fiber, except transmission basic mode is LP01Beyond mould, LP can be at least transmitted11Mould, root
Should have according to mode characteristic：Normalized frequencyV>2.405.To realize separating LP02Mould, then its normalized frequencyV>3.832.As schemed
3 connecting curves for showing different mode in the optical fiber shown in the present invention.Will light from the first fibre core 2 be input into when, the 3rd fibre core 4
In mode of energy with transmission range change curve.As seen from the figure, after being changed into three-core structure from twin-core structure, different mode it
Between coupling length difference substantially become big.LP shown in Fig. 201Mould, LP11Mould, LP21Coupling length ratio between mould, LP02 moulds
For：26: 3.44: 1.476: 1.This change can so be understood.Three-core structure may be considered in twin-core structure
The heart adds a fibre core and obtains again.And, i.e., between pattern overlapping region larger pattern shorter for coupling length, increase a fibre
After core, the pattern between two adjacent fibre cores is overlapped can be bigger, thus is more prone to strong coupling, therefore, from side, fibre core is defeated
The light for entering quickly first through the second fibre core 3, then can be coupled opposite side fibre core long.And it is more long for coupling length in twin-core structure
Pattern, after increased a fibre core, its coupling length reduce DeGrain.Can effectively be increased using three-core structure
The difference of the coupling length between different mode, so that modal cutoff is more easy.As seen from Figure 3, the LP of the first fibre core 202
Mould is transmitted by a segment distance, will be coupled with the second fibre core 3, then after being coupled with the 3rd fibre core 4, is transferred to the 3rd fibre core
4.If being transmitted through this segment distance, other patterns are all difficult to be coupled to the 3rd fibre core 4, then take fiber lengths for LP02Mould is from first
Fibre core 2 is coupled to the coupling length of the 3rd fibre core 4, when input light is input into from the first fibre core 2, it is possible to by LP02Mould is isolated
Come.
Fig. 5 provides structure shown in Fig. 1 for separating LP02During mould, the output energy of the 3rd fibre core 4 is with wavelength change curve.
As seen from the figure, LP02Mould can low-loss output, and LP in the range of wider bandwidth01Mould, LP11The energy of mould is all very low.I.e.
LP02Mould can be efficiently separated, and other patterns crosstalk very little.
Fig. 6 provides normalized frequency V, core centre spacing, and d is identical, and fibre core different situation poor from cladding index
Under, light from side fibre core be input into when, the energy curve of opposite side fibre core.As seen from the figure, when fibre core and cladding index are poor larger
When, the energy conversion of high-order mode is higher, while the coupling length difference between different mode is larger.Because, in normalization frequency
In the case of rate V identicals, fibre core is poor with cladding index bigger, then the effective refractive index difference between pattern is also bigger, namely not
Energy distribution difference with pattern in covering is also bigger.This results in the further increasing of the difference of coupling length between different mode
Greatly.Therefore, it is more excellent using the poor performance that can make mode splitter of larger fibre core and cladding index.
Obviously, optical fiber of the present invention can also serve as pattern bundling device.The light of synthesis will be needed respectively from both sides fibre core
Input, after the short pattern of coupling length is coupled, reaches opposite side fibre core, is exported after converging with another light beam.When pattern closes beam,
Coupling length pattern more long should first be synthesized, then synthesize the shorter pattern of coupling length.The final conjunction Shu Guang for obtaining multiple patterns.
Embodiment one：
Below in conjunction with brief description of the drawings the preferred embodiments of the present invention.As shown in figure 1, the present embodiment realizes LP02Mould and LP01
Mould, LP11Separation between mould.Matrix material of optic fibre 1 is pure quartz, and three radiuses of fibre core are 6.15 μm, fibre core and covering
Refringence be 0.012.The centre distance of adjacent fibre core is 22 μm.Light is input into from the first fibre core 2, LP02Mould is from the 3rd fibre core
4 outputs, other patterns are exported from the first fibre core 2.Its coupling length curve is as shown in Figure 3.It can be seen that, LP02Mode-coupling length is much
Less than the coupling length of another two pattern.Fiber lengths are taken for 33.5 mm.The energy of the different mode of the output of the 3rd fibre core 4 is such as
Shown in Fig. 4.It can be seen that, in 1.48-1.515 μ m wavelength ranges, LP02The power output of mould is all higher than -1 dB, and another two pattern
Energy be respectively less than -30 dB, therefore, the exportable LP with low crosstalk of the 3rd fibre core 402Mould.
Above-mentioned accompanying drawing is only explanatory view, protection scope of the present invention is not formed and is limited.
Claims (1)
1. a kind of fiber mode separator, including three fibre cores and covering, the covering are made up of host material；Its feature exists
In：In line, middle fiber core is identical with the centre distance of both sides fibre core for the line of centres of three fibre cores, three fibres
The index distribution of core is identical, three fibre cores diameters are identical, and the normalized frequency V of three fibre cores meets V>
3.832,Wherein a is fiber core radius, and λ is operation wavelength, ncoreIt is fiber core refractive index,
ncladIt is cladding index；The refractive index a of the three fibre cores and refractive index n of coveringcladDifference meet：ncore-nclad>
0.01；Meet between middle fiber core and the centre distance d and fiber core radius a of both sides fibre core：d>2a+3μm.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201310692492.0A CN104076433B (en) | 2013-12-18 | 2013-12-18 | A kind of fiber mode separator |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201310692492.0A CN104076433B (en) | 2013-12-18 | 2013-12-18 | A kind of fiber mode separator |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| CN104076433A CN104076433A (en) | 2014-10-01 |
| CN104076433B true CN104076433B (en) | 2017-05-31 |
Family
ID=51597811
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN201310692492.0A Active CN104076433B (en) | 2013-12-18 | 2013-12-18 | A kind of fiber mode separator |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN104076433B (en) |
Families Citing this family (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2016170356A (en) * | 2015-03-13 | 2016-09-23 | 株式会社フジクラ | Optical fiber and method of manufacturing the same |
| CN106019475B (en) * | 2016-07-28 | 2019-04-02 | 江苏大学 | A kind of less fundamental mode optical fibre device |
| CN106304419B (en) * | 2016-08-15 | 2020-06-12 | 上海交通大学 | Wireless forward transmission system for digital optical transmission based on multi-core optical fiber |
| CN108964765B (en) * | 2017-05-19 | 2021-05-28 | 吕婧菲 | Multimode optical fiber transmission device |
| WO2021214976A1 (en) * | 2020-04-24 | 2021-10-28 | 日本電信電話株式会社 | Intermode loss difference compensator |
| CN112162355A (en) * | 2020-09-18 | 2021-01-01 | 北京交通大学 | Optical fiber mode selection coupler based on symmetrical double-core few-mode optical fiber |
Citations (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US6538807B2 (en) * | 2000-09-07 | 2003-03-25 | Sumitomo Electric Industries, Ltd. | Amplification optical fiber, fiber optic amplifier, optical transmitter, and optical communication system |
| US7412142B2 (en) * | 2006-05-19 | 2008-08-12 | Corning Incorporated | Optical fiber with plurality of air holes and stress rods |
| CN101339269A (en) * | 2008-08-12 | 2009-01-07 | 江苏大学 | Optical fibre wavelength-division multiplex device |
| CN103154790A (en) * | 2010-10-05 | 2013-06-12 | 株式会社藤仓 | Polarization-maintaining optical fiber |
-
2013
- 2013-12-18 CN CN201310692492.0A patent/CN104076433B/en active Active
Patent Citations (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US6538807B2 (en) * | 2000-09-07 | 2003-03-25 | Sumitomo Electric Industries, Ltd. | Amplification optical fiber, fiber optic amplifier, optical transmitter, and optical communication system |
| US7412142B2 (en) * | 2006-05-19 | 2008-08-12 | Corning Incorporated | Optical fiber with plurality of air holes and stress rods |
| CN101339269A (en) * | 2008-08-12 | 2009-01-07 | 江苏大学 | Optical fibre wavelength-division multiplex device |
| CN103154790A (en) * | 2010-10-05 | 2013-06-12 | 株式会社藤仓 | Polarization-maintaining optical fiber |
Non-Patent Citations (1)
| Title |
|---|
| Mode splitter based on triple-core waveguide;Zhi Wang etc;<Optics Express>;20061030;第14卷(第22期);10324-10331 * |
Also Published As
| Publication number | Publication date |
|---|---|
| CN104076433A (en) | 2014-10-01 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| CN104076433B (en) | A kind of fiber mode separator | |
| US11855755B2 (en) | WDM1r combiner for PON | |
| CN101339273B (en) | Optical fibre mode converter | |
| CN107272115B (en) | Mode multiplexer/demultiplexer based on three-core optical fiber | |
| CN102749676B (en) | Cross waveguide based on linear tapered multimode interference principle | |
| CN103698842B (en) | A kind of optical fiber mode add-drop multiplexer | |
| CN103698843A (en) | Low-degeneracy few-mode fiber | |
| CN102904641A (en) | Communication system based on few-mode optical fiber | |
| JP6288772B2 (en) | Mode multiplexer / demultiplexer and mode multiplexing communication system | |
| CN108508539A (en) | Silicon substrate wavelength division multiplexer based on taper asymmetrical directional coupler | |
| JP5988100B2 (en) | Mode multiplexer / demultiplexer | |
| CN103728694B (en) | A kind of broadband optical fiber mode converter | |
| CN109725386B (en) | Multiband Broadband Optical Waveguide Mode Converter | |
| Reyes-Vera et al. | Mode selective coupler based in a dual-core photonic crystal fiber with non-identical cores for spatial mode conversion | |
| CN104345380B (en) | A kind of dual mode optical fiber | |
| US8594474B2 (en) | Mach-Zehnder wavelength division multiplexer having flat passband and low crosstalk | |
| Lan et al. | Mode multiplexer/demultiplexer based on tapered multi-core fiber | |
| CN115079345B (en) | Double-conical asymmetric directional coupler-based light polarization beam splitting rotator | |
| US10101531B2 (en) | Polarization mode converter | |
| CN207148361U (en) | A kind of pattern multiplexer/demultiplexer based on three core fibres | |
| CN108508530A (en) | Couple four-core fiber | |
| JP6503513B2 (en) | Multicore fiber | |
| JP2015075616A (en) | Method for manufacturing planar optical waveguide and mode multiplexer/demultiplexer | |
| CN103728689B (en) | A kind of high birefringence optical fiber | |
| JP5842277B2 (en) | Mode multiplexer / demultiplexer and design method thereof |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| C06 | Publication | ||
| PB01 | Publication | ||
| C10 | Entry into substantive examination | ||
| SE01 | Entry into force of request for substantive examination | ||
| GR01 | Patent grant | ||
| GR01 | Patent grant | ||
| TR01 | Transfer of patent right |
Effective date of registration: 20171117 Address after: 212100 Zhenjiang province Jiangsu city Dantu District Shangdang ecological Automobile Industrial Park No. 8 Patentee after: JIANGSU HUIZHI INTELLECTUAL PROPERTY SERVICES CO., LTD. Address before: Zhenjiang City, Jiangsu Province, 212013 Jingkou District Road No. 301 Patentee before: Jiangsu University |
|
| TR01 | Transfer of patent right | ||
| TR01 | Transfer of patent right |
Effective date of registration: 20200521 Address after: 215500 No.13, Caotang Road, Changshu, Suzhou, Jiangsu Province Patentee after: Changshu intellectual property operation center Co., Ltd Address before: 212100 Zhenjiang province Jiangsu city Dantu District Shangdang ecological Automobile Industrial Park No. 8 Patentee before: JIANGSU HUIZHI INTELLECTUAL PROPERTY SERVICES Co.,Ltd. |
|
| TR01 | Transfer of patent right | ||
| CP02 | Change in the address of a patent holder |
Address after: 215500 5th floor, building 4, 68 Lianfeng Road, Changfu street, Changshu City, Suzhou City, Jiangsu Province Patentee after: Changshu intellectual property operation center Co.,Ltd. Address before: No.13 caodang Road, Changshu City, Suzhou City, Jiangsu Province Patentee before: Changshu intellectual property operation center Co.,Ltd. |
|
| CP02 | Change in the address of a patent holder |