A kind of preparation method of polarization maintaining optical fibreTechnical field
The present invention relates to the technical field of fiber manufacturing, be specifically related to the preparation method of a kind of polarization maintaining optical fibre.
Background technology
Polarization-maintaining fiber (Polarization Maintaining Optical Fiber, PMF) is called for short polarization maintaining optical fibre.Owing to the polarization characteristic of fiber waveguide has the most special purposes, adding to have with standard single-mode fiber and compare the good compatibility, polarization maintaining optical fibre is widely used in fields such as fiber optic communication, Fibre Optical Sensor, light polarization Sensitive Apparatuses.
Since nineteen seventies, each state is all competitively researching and developing high performance polarization maintaining optical fibre.The kind of polarization maintaining optical fibre is a lot, has different manufacture methods according to different types of polarization maintaining optical fibre.Circular polarization maintaining optical fibre mainly uses boring method and fluting method to realize, and fan-shaped polarization maintaining optical fibre then more uses the chemical gaseous phase manufacturing process improved to manufacture.
But being as the large-scale application of polarization maintaining optical fibre, large batch of mass manufacturing techniques is had higher requirement by it.At present the polarization-preserving fiber preform size of technique is less than normal, and within size is typically confined to 50mm diameter and length of string is within 50km, with the 200mm diameter optical wand of Standard single-mode fiber, the manufacturing process of Gao Kela 3000km falls far short.And along with the technology that optical fibre gyro, Fibre Optical Sensor etc. are new develops, the manufacture demand of new type polarization maintaining optical fibre also emerges in an endless stream, the chemical gaseous phase manufacturing process etc. of existing boring method, fluting method and improvement has respective limitation, it is difficult to realize the manufacture of diversified large scale polarization-preserving fiber preform.
In view of this, it is badly in need of providing a kind of and manufactures Multiple Shape, the manufacture method of large-sized polarization-preserving fiber preform, can effectively drive the manufacturing technology of polarization maintaining optical fibre and the ability of batch production, drive the development of optical fiber sensing technology.
Summary of the invention
The problem existed for prior art, the invention provides the preparation method of a kind of polarization maintaining optical fibre, comprises the following steps:
Chemical vapour deposition, Plasma Enhanced Chemical Vapor Deposition (PECVD), outside chemical vapor deposition method or axial vapor deposition method is used to prepare plug；
According to plug and the size of required prefabricated rods, the mould of semicylinder prepared by the material using temperature resistant range to be 2500～3000 degrees Celsius；
Injecting melted silica liquid in the mould of semicylinder, the quartz obtaining the semicolumn bodily form after it condenses partly cuts sleeve pipe, and quartz partly cuts the periphery of sleeve pipe and combined by center tangent plane and semicircle cambered surface；
Partly cut at quartz and on the center tangent plane of sleeve pipe, polish half stressed zone groove of required form and the half plug groove suitable with plug size；
Two semicylinder quartz are partly cut sleeve combination together, and two halves plug groove is combined as plug hole, and groove combination in two halves stressed zone forms hole, stressed zone, plug is put into plug hole, by melted heating, two quartz is partly cut sleeve pipe and is melt into an entirety with plug；
Silicon dioxide and the mixture of diboron trioxide is filled, it is thus achieved that there is the polarization-preserving fiber preform in the hole, stressed zone of required form in hole, stressed zone；
Polarization-preserving fiber preform is drawn on wire-drawer-tower, the polarization maintaining optical fibre of various diameter can be obtained.
In the above-mentioned methods, described temperature resistant range be the material of 2500～3000 degrees Celsius be graphite.
In the above-mentioned methods, generally circular in shape, fan-shaped, the hexagon, oval or square in hole, described stressed zone.
In the above-mentioned methods, the number in hole, described stressed zone is two, and is oppositely arranged on the both sides in described plug hole.
In the above-mentioned methods, the preform diameter that hole, described stressed zone is circular is 150mm to the maximum, a length of more than the 500km of polarization maintaining optical fibre being drawn into.
In the above-mentioned methods, described polarization-preserving fiber preform can be drawn into silica clad a diameter of 40～200um, coating diameter be 80～400um polarization maintaining optical fibre.
In the above-mentioned methods, quartz partly being cut by polishing method or aciding the middle part equating of the semicircle cambered surface of sleeve pipe, making semicircle cambered surface become both sides is that arc, the adjusting type quartz of mid-plane partly cut sleeve pipe.
In the above-mentioned methods, the part by weight scope of described silicon dioxide and diboron trioxide is 9:(0.2～2).
The present invention polish half hole, stressed zone of required form and the half plug groove suitable with plug size by partly cutting at preparation quartz on sleeve pipe, and by integrated combination fusion method, the quartz that two are matched partly is cut sleeve pipe combines together with plug, achieve hole, stressed zone and the manufacture of large-sized polarization-preserving fiber preform of Multiple Shape, can guarantee that again the optical property that polarization-preserving fiber preform is good, effectively reduce the manufacturing cost of polarization maintaining optical fibre and promote the manufacture efficiency of polarization maintaining optical fibre.
Accompanying drawing explanation
The schematic diagram of the polarization-preserving fiber preform plug that Fig. 1 provides for the present invention；
The structural representation of the embodiment one that Fig. 2 provides for the present invention；
The radial section schematic diagram of the embodiment two that Fig. 3 provides for the present invention；
The radial section schematic diagram of the embodiment three that Fig. 4 provides for the present invention；
The radial section schematic diagram of the embodiment four that Fig. 5 provides for the present invention；
The radial section schematic diagram of the embodiment five that Fig. 6 provides for the present invention；
The radial section schematic diagram of the embodiment six that Fig. 7 provides for the present invention.
Detailed description of the invention
Present invention achieves a kind of stressed zone hole Multiple Shape and the manufacture of large-sized polarization maintaining optical fibre, the manufacture of the polarization-preserving fiber preform of more than diameter 80mm or even 150mm can be realized simultaneously, can guarantee that again the optical property that polarization-preserving fiber preform is good, effectively reduce the manufacturing cost of polarization maintaining optical fibre and promote the manufacture efficiency of polarization maintaining optical fibre.Below in conjunction with specific embodiment and Figure of description, the present invention is described in detail.
The invention provides the preparation method of a kind of polarization maintaining optical fibre, comprise the following steps:
S1, method initially with modified chemical vapor deposition (MCVD), Plasma Enhanced Chemical Vapor Deposition (PECVD) (PCVD), outside chemical vapor deposition method (OVD) or axial vapor deposition method (VAD) prepare plug, as shown in Figure 1, plug 11 comprises sandwich layer 12 and is wrapped in the first covering 13 of sandwich layer 12 periphery, first covering 13 can be during polarization-preserving fiber preform integrated combination, avoid introduced contaminants to enter sandwich layer 12, thus avoid the optical property of optical fiber to be affected.
S2, employing integrated combination fusion method, according to plug 11 and the size of required prefabricated rods, use the high temperature resistant materials reaching 2500～3000 degrees Celsius such as graphite to prepare the mould of semicylinder.
S3, in the mould of semicylinder, it is infused in the silica liquid that temperature reaches after 2300 degrees Celsius melted, after it condenses, the quartz of the semicolumn bodily form that can obtain required form partly cuts sleeve pipe, and quartz partly cuts the periphery of sleeve pipe and combined by center tangent plane and semicircle cambered surface.
S4, partly cut at quartz and on the center tangent plane of sleeve pipe, polish half stressed zone groove of required form and the half plug groove suitable with plug 11 size.
S5, two semicylinder quartz are partly cut sleeve combination together, half plug groove is combined as plug hole, two and half stressed zone groove combinations form hole, stressed zone, plug 11 is put into plug hole, then by the way of melted heating, two semicylinder quartz are partly cut sleeve pipe and is melt into an entirety with plug 11, form quartz socket tube.
S6, in the hole, stressed zone formed, fill silicon dioxide and the mixture of diboron trioxide, it is thus achieved that must have the polarization-preserving fiber preform in hole, difform stressed zone.The part by weight scope of silicon dioxide and diboron trioxide mixture is 9:(0.2～2), thus it is prepared as high cross-talk or the conventional good crackless polarization-preserving fiber preform of cross-talk end surface grinding；
S7, by obtain polarization-preserving fiber preform draw on wire-drawer-tower, the polarization maintaining optical fibre of various diameter can be obtained.
Use the polarization-preserving fiber preform that said method obtains, wire-drawer-tower draw, silica clad diameter can be drawn into 40～200um, coating diameter 80～400um polarization maintaining optical fibre.
In the case of operation wavelength is 850nm, decay can be less than 2.0dB/km, and extinction ratio is higher than 40dB/100m, claps long less than 2.5mm；In the case of operation wavelength is 1550nm, decay can be less than 0.5dB/km, and extinction ratio is higher than 40dB/100m, claps long less than 3mm.
Wherein, the shape in hole, stressed zone can be circle, sector, hexagon, oval or square.Wherein, the number in circular, fan-shaped, hexagon or square hole, stressed zone is two, and is oppositely arranged on the both sides in plug hole, and the number in oval hole, stressed zone is 1, is arranged on the periphery in plug hole.
The exemplary embodiments of the polarization-preserving fiber preform of the shape in hole, stressed zone the most circular, fan-shaped, square, hexagonal.
Embodiment one
As in figure 2 it is shown, the quartz for the hole, circular stressed zone 31 of present invention offer partly cuts sleeve pipe schematic diagram, plug hole 21 is circular, and now preform diameter maximum can be 150mm, a length of more than the 500km of polarization maintaining optical fibre being drawn into.
The 6 kinds of various sizes of circular polarization maintaining optical fibres produced according to the method for embodiment one, the test comparison result of each parameter of these 6 kinds of circular polarization maintaining optical fibres is as shown in table 1.
16 kinds of table has the test parameter of the polarization maintaining optical fibre in hole, circular stressed zone
Embodiment two
As it is shown on figure 3, polarization maintaining optical fibre has hole, fan-shaped stressed zone 32.
Embodiment three
As shown in Figure 4, polarization maintaining optical fibre has hole, square stressed zone 33.
Embodiment four
As it is shown in figure 5, polarization maintaining optical fibre has hole, hexagon stressed zone 34.
Respectively producing 2 kinds of optical fiber, altogether 6 kinds of optical fiber according to the method for embodiment two, embodiment three and embodiment four, the test comparison result of each parameter is as shown in table 2.
The test parameter of the polarization maintaining optical fibre of table 2 different stressed zone hole shape
In the present invention, when the mixture using silicon dioxide and diboron trioxide fills hole, stressed zone, owing to mixture is under high-temperature fusion, its internal air can be discharged, will result in hole, stressed zone can reduce under high-temperature fusion, thus cause the polarization-preserving fiber preform 20 external diameter in both sides, hole, stressed zone to reduce, thus causing the polarization maintaining optical fibre finally drawn is not a regular circle.It is the embodiment of the scheme for this improvement of problem below.
As shown in Figure 6 and Figure 7, quartz partly being cut by polishing method or aciding the middle part equating of the semicircle cambered surface of sleeve pipe 20, making semicircle cambered surface become both sides is that arc, the adjusting type quartz of mid-plane partly cut sleeve pipe 40.
Embodiment five
As shown in Figure 6, polarization maintaining optical fibre has hole, circular stressed zone 31.When polarization-preserving fiber preform is placed on high-temperature fusion wire drawing under wire-drawer-tower, adjusting type quartz partly cuts the plane area of sleeve pipe 40 can become round under high-temperature fusion with capillary effect, in the case of hole, stressed zone 21 collapsing reduces, the external diameter of the polarization maintaining optical fibre of its both sides also has corresponding reduction, the external diameter of the polarization maintaining optical fibre formed can present a circle the most regular, and its non-circularity of cladding remains to keep good value, within caning be controlled in 1%.
Embodiment six
As it is shown in fig. 7, polarization maintaining optical fibre has hole, oval stressed zone 35.Plug 11, can be to the long axis direction extension in oval hole, stressed zone 35 under high-temperature fusion, and the major axis in oval hole, stressed zone 35 the most also synchronizes finally fire the all-in-one-piece polarization-preserving fiber preform containing elliptical core to plug 11 collapsing.Owing to the long axis direction in oval hole, stressed zone 35 is when evacuation is melted, two adjusting type quartz can be driven partly to cut the sleeve pipe 40 diameter to central longitudinal axis direction and to reduce collapsing, now the quartzy plane area partly cutting sleeve pipe 40 of adjusting type can become round under high-temperature fusion under surface tension effects, so that the external boundary of the elliptical core polarization-preserving fiber preform ultimately formed still presents a regular circle, when wire-drawer-tower is drawn into polarization maintaining optical fibre, its non-circularity of cladding remains to keep good value, within caning be controlled in 1%.
Respectively preparing a kind of polarization maintaining optical fibre according to embodiment five and embodiment six, design parameter is as shown in table 3.
Table 3 has the test parameter of the fibre core polarization maintaining optical fibre in hole, oval stressed zone
| Example 13 | Example 14 |
| Optical wand diameter mm | 45 | 68 |
| Cladding diameter μm | 80 | 125 |
| Coating diameter μm | 165 | 245 |
| Can drawing optical fiber length km | 122 | 152 |
| Operation wavelength nm | 1550 | 1550 |
| Decay dB/km | 0.58 | 0.59 |
| Extinction ratio dB/100m | 35 | 36 |
| Clap long mm | 2.6 | 2.8 |
| Non-circularity of cladding | 0.95% | 0.92% |
The present invention has a following beneficial effect:
1, present invention achieves the manufacture of a kind of large scale polarization-preserving fiber preform, can disposably draw the polarization maintaining optical fibre of hundreds of km, thus can effectively reduce the manufacturing cost of polarization maintaining optical fibre, effectively promote the manufacture efficiency of polarization maintaining optical fibre.
2, the present invention can obtain the polarization maintaining optical fibre of multiple stressed zone hole shape, is suitable for the development of all types of Novel polarization-maintaining opticals.
3, the present invention can be suitable for preparing high cross-talk or the conventional good crackless polarization maintaining optical fibre of cross-talk end surface grinding.
The present invention polish half hole, stressed zone of required form and the half plug groove suitable with plug size by partly cutting at preparation quartz on sleeve pipe, and by integrated combination fusion method, the quartz that two are matched partly is cut sleeve pipe combines together with plug, achieve hole, stressed zone and the manufacture of large-sized polarization-preserving fiber preform of Multiple Shape, can guarantee that again the optical property that polarization-preserving fiber preform is good, effectively reduce the manufacturing cost of polarization maintaining optical fibre and promote the manufacture efficiency of polarization maintaining optical fibre.
The present invention is not limited to above-mentioned preferred forms, and anyone should learn the structure change made under the enlightenment of the present invention, and every have same or like technical scheme, within each falling within protection scope of the present invention with the present invention.