阅读说明：本技术 椭圆芯保偏光纤预制棒、椭圆芯保偏光纤及其制造工艺 (Elliptical core polarization maintaining optical fiber preform, elliptical core polarization maintaining optical fiber and manufacturing process thereof ) 是由 宋静波 黄勇 于 2021-08-20 设计创作，主要内容包括：本发明公开了一种椭圆芯保偏光纤预制棒制造工艺,包含：准备一根石英棒,沿石英棒轴心对称形成贯穿整根石英棒,且两两并排相交的N个孔,N≥2；对石英棒进行清洗,在孔的内壁进行芯层沉积；对沉积后的石英棒进行塌缩,制成一根实心椭圆芯棒；根据实际需要,可在实心椭圆芯棒外围套装石英套管,进行熔缩和拉伸处理,得到椭圆芯保偏光纤预制棒。本发明还公开了一种利用所述椭圆芯保偏光纤预制棒制造工艺的椭圆芯保偏光纤制造工艺,一种由所述所述椭圆芯保偏光纤预制棒制造工艺制造的椭圆芯保偏光纤预制棒,一种由所述椭圆芯保偏光纤制造工艺制造的椭圆芯保偏光纤。本发明相对现有工艺,工序简单,椭圆芯长短轴比例精准可控,精度高,稳定性好,能获得较高的双折射。(The invention discloses a process for manufacturing an elliptical core polarization maintaining optical fiber preform, which comprises the following steps: preparing a quartz rod, and symmetrically forming N holes which penetrate through the whole quartz rod along the axis of the quartz rod and are intersected side by side in pairs, wherein N is more than or equal to 2; cleaning the quartz rod, and depositing a core layer on the inner wall of the hole; collapsing the deposited quartz rod to prepare a solid elliptical core rod; according to actual needs, a quartz sleeve can be sleeved on the periphery of the solid elliptical core rod, and the elliptical core polarization-maintaining optical fiber preform rod can be obtained by performing fusion and stretching treatment. The invention also discloses a manufacturing process of the elliptical core polarization maintaining optical fiber by utilizing the manufacturing process of the elliptical core polarization maintaining optical fiber preform, an elliptical core polarization maintaining optical fiber preform manufactured by the manufacturing process of the elliptical core polarization maintaining optical fiber preform, and an elliptical core polarization maintaining optical fiber manufactured by the manufacturing process of the elliptical core polarization maintaining optical fiber. Compared with the prior art, the method has the advantages of simple process, accurate and controllable ratio of the major axis and the minor axis of the elliptical core, high precision, good stability and capability of obtaining higher birefringence.)

1. A process for manufacturing an elliptical core polarization maintaining optical fiber preform is characterized by comprising the following steps:

preparing a quartz rod, and symmetrically forming N holes which penetrate through the whole quartz rod along the axis of the quartz rod and are intersected side by side in pairs, wherein N is more than or equal to 2;

step two, cleaning the quartz rod, heating, extending and thinning the quartz rod to a required size, and then depositing a core layer;

and step three, after the deposition is finished, the rod is contracted to obtain the elliptical core polarization maintaining optical fiber preform.

2. A process for manufacturing an elliptical core polarization maintaining optical fiber preform is characterized by comprising the following steps:

preparing a quartz rod, and symmetrically forming N holes which penetrate through the whole quartz rod along the axis of the quartz rod and are intersected side by side in pairs, wherein N is more than or equal to 2;

cleaning the quartz rod, and depositing a core layer on the inner wall of the hole;

step three, collapsing the deposited quartz rod to prepare a solid elliptical core rod;

and step four, sleeving a quartz sleeve on the periphery of the solid elliptical core rod for fusing and stretching to obtain the elliptical core polarization-maintaining optical fiber preform.

3. The process of making an elliptical core, polarization maintaining fiber preform according to claim 1 or 2, wherein: and N is 3, and the drilling depth is equal to the length of the quartz rod.

4. The process of making an elliptical core, polarization maintaining fiber preform according to claim 1 or 2, wherein: the circle centers of the quartz rods and the circle centers of all the through holes on any radial section are all positioned on the same straight line, and the distance between the circle centers of the adjacent holes is smaller than the sum of the radiuses of the two holes.

5. The process of making an elliptical core, polarization maintaining fiber preform according to claim 1 or 2, wherein: the ellipticity of the elliptical core is controlled by controlling the distance between the centers of the punched holes, and the ratio range of the major axis to the minor axis of the elliptical core is 2: 1 to 6: 1.

6. the elliptical core polarization maintaining fiber preform fabricating process of claim 2, wherein: the circular outer surface of the elliptical core rod cladding is tangent to the inner surface of the quartz sleeve.

7. An elliptical core polarization maintaining optical fiber preform manufactured by the elliptical core polarization maintaining optical fiber preform manufacturing process of claim 1 or 2.

8. A process for manufacturing an elliptical core polarization maintaining optical fiber using the elliptical core polarization maintaining optical fiber preform manufacturing process of claim 1 or 2, further comprising the steps of:

and drawing the elliptical core polarization maintaining optical fiber preform into a bare optical fiber with a required size, and coating inner layer and outer layer coatings on the surface of the bare optical fiber to obtain the elliptical core polarization maintaining optical fiber.

9. An elliptical core polarization maintaining optical fiber manufactured by the manufacturing process of the elliptical core polarization maintaining optical fiber of claim 8.

Technical Field

The invention relates to the field of communication, in particular to a manufacturing process of an elliptical core polarization maintaining optical fiber preform. And, an elliptical core polarization maintaining optical fiber manufacturing process using the elliptical core polarization maintaining optical fiber preform manufacturing process, an elliptical core polarization maintaining optical fiber preform manufactured by the elliptical core polarization maintaining optical fiber preform manufacturing process, and an elliptical core polarization maintaining optical fiber manufactured by the elliptical core polarization maintaining optical fiber manufacturing process.

The problems of low birefringence and poor consistency of the elliptical core polarization maintaining optical fiber manufactured by the traditional process are solved.

Background

Polarization maintaining fibers are widely used, and typical examples thereof include panda-type polarization maintaining fibers, bow tie-type polarization maintaining fibers, elliptical clad-type polarization maintaining fibers, elliptical core polarization maintaining fibers, photonic crystal polarization maintaining fibers, and the like. At present, the polarization maintaining fiber which is widely applied and has the most mature technology in China is a panda type polarization maintaining fiber. The polarization maintaining fiber has stable production process and consistent basic performance.

However, optical fibers of different structures have different advantages and disadvantages, and the polarization maintaining optical fibers can be generally classified into

One of the two types is a stress type polarization maintaining fiber, and the panda type polarization maintaining fiber, the bow tie type polarization maintaining fiber and the elliptical cladding type polarization maintaining fiber belong to the stress type polarization maintaining fiber; the other type is a non-stress type polarization maintaining fiber, and the elliptical core polarization maintaining fiber and the photonic crystal polarization maintaining fiber belong to the non-stress type polarization maintaining fiber.

The influence of different application scenes on the performance of the optical fiber is different, and the optical fiber current sensor and the optical fiber are used alone

The application angle of the gyroscope is analyzed, and the general development trend is basically as follows: (1) the large stress area type optical fiber is developed to the small stress area type optical fiber; (2) since the non-stressed optical fiber has better temperature stability, the development from the stressed optical fiber to the non-stressed optical fiber has been advanced.

In the case of an elliptical core polarization maintaining fiber, the polarization maintaining characteristic is realized by geometric birefringence on the surface, but the elliptical core has geometric birefringence and some stress birefringence in nature, and after all, the material of the elliptical core is different from that of the fiber cladding. The biggest problem of the current elliptical core polarization maintaining fiber is that the linear birefringence of the fiber is relatively low (namely the beat length is long), and the fiber can only be used for a low-precision fiber optic gyroscope. The low linear birefringence of an elliptical core polarization maintaining fiber is mainly determined by the production process, and a general production flow is shown in fig. 1, specifically as follows:

1) preparing a circular preform of suitable parameters, as shown in fig. 1 at a;

2) the circular preform is laterally ground and polished to have an oval-like shape, as shown at B in fig. 1;

3) melting the grinded and polished preform at high temperature to make the preform have a circular shape, and the original circular fiber core becomes an ellipse, as shown in fig. 1C;

4) drawing to form the elliptical core polarization maintaining optical fiber.

In the process, the machining procedure is complex, the machining process difficulty is high, the proportion of the long axis and the short axis of the fiber core is difficult to control in the actual production process, and the beat length of the processed optical fiber is long, namely the birefringence is poor.

Disclosure of Invention

In this summary, a series of simplified form concepts are introduced that are simplifications of the prior art in this field, which will be described in further detail in the detailed description. This summary of the invention is not intended to identify key features or essential features of the claimed subject matter, nor is it intended to be used as an aid in determining the scope of the claimed subject matter.

The invention aims to solve the technical problem of providing the process for the elliptical core polarization-maintaining optical fiber preform rod, which is simple in process compared with the prior art, accurate and controllable in proportion of the long axis and the short axis of the processing process and good in birefringence.

Correspondingly, the invention also provides a manufacturing process of the elliptical core polarization maintaining optical fiber by utilizing the manufacturing process of the elliptical core polarization maintaining optical fiber preform, an elliptical core polarization maintaining optical fiber preform manufactured by the manufacturing process of the elliptical core polarization maintaining optical fiber preform, and an elliptical core polarization maintaining optical fiber manufactured by the manufacturing process of the elliptical core polarization maintaining optical fiber.

In order to solve the above technical problems, the present invention provides a first manufacturing process of an elliptical core polarization maintaining optical fiber preform, comprising the following steps:

preparing a quartz rod, and forming N holes which penetrate through the whole quartz rod along the axis of the quartz rod and are intersected side by side in pairs, wherein N is more than or equal to 2; namely, the holes are arranged in parallel, the centers of the holes are on the same straight line, and a symmetrical structure taking the axis of the quartz rod as the center is formed;

step two, cleaning the quartz rod, heating, extending and thinning the quartz rod to a required size, and then depositing a core layer;

and step three, after the deposition is finished, the rod is contracted to obtain the elliptical core polarization maintaining optical fiber preform.

In order to solve the above technical problems, the present invention provides a second manufacturing process of an elliptical core polarization maintaining optical fiber preform, comprising the following steps:

preparing a quartz rod, and forming N holes which penetrate through the whole quartz rod along the axis of the quartz rod and are intersected side by side in pairs, wherein N is more than or equal to 2; namely, the holes are arranged in parallel and intersected, the centers of the holes are on the same straight line, and a symmetrical structure taking the axis of the quartz rod as the center is formed;

cleaning the quartz rod, and depositing a core layer on the inner wall of the hole;

step three, collapsing the deposited quartz rod to prepare a solid elliptical core rod;

and step four, sleeving a quartz sleeve on the periphery of the solid elliptical core rod for fusing and stretching to obtain the elliptical core polarization-maintaining optical fiber preform.

Optionally, the manufacturing process of the first or second elliptical core polarization maintaining optical fiber preform is further improved, wherein N is 3, and the drilling depth is equal to the length of the quartz rod.

Optionally, the manufacturing process of the first or second elliptical-core polarization-maintaining optical fiber preform is further improved, the circle center of the quartz rod and the circle centers of all the through holes on any radial section are all located on the same straight line, and the circle center distance of the adjacent holes is smaller than the sum of the radii of the two holes.

Optionally, the manufacturing process of the first or second elliptical core polarization maintaining optical fiber preform is further improved, the ellipticity of the elliptical core is controlled by controlling the distance between the centers of the holes, and the ratio of the major axis to the minor axis of the elliptical core is in the range of 2: 1 to 6: 1.

optionally, the second manufacturing process of the elliptical core polarization maintaining optical fiber preform is further improved, and the circular outer surface of the elliptical core rod cladding is tangent to the inner surface of the quartz sleeve.

In order to solve the technical problems, the invention provides an elliptical core polarization-maintaining optical fiber preform manufactured by the manufacturing process of the first or second elliptical core polarization-maintaining optical fiber preform.

In order to solve the above technical problems, the present invention provides a manufacturing process of an elliptical core polarization maintaining optical fiber using the first or second manufacturing process of an elliptical core polarization maintaining optical fiber preform, further comprising the following steps:

and drawing the elliptical core polarization maintaining optical fiber preform into a bare optical fiber with a required size, and coating inner layer and outer layer coatings on the surface of the bare optical fiber to obtain the elliptical core polarization maintaining optical fiber.

In order to solve the technical problem, the invention provides the elliptical core polarization maintaining optical fiber manufactured by the manufacturing process of the elliptical core polarization maintaining optical fiber.

The invention symmetrically forms two holes which are intersected side by side and penetrate through the whole quartz rod in the axis of the quartz rod, the holes are arranged side by side to form an ellipse-like structure, the quartz rod is heated, extended and thinned to the required size after being cleaned, and then the core layer deposition is carried out; and after the deposition is finished, the rod is contracted to obtain the elliptical core polarization maintaining optical fiber preform.

Or, forming two holes which are intersected side by side and penetrate through the whole quartz rod in axial symmetry on the quartz rod, wherein the holes are in an ellipse-like structure side by side, cleaning the quartz rod, and depositing a core layer on the inner wall of the hole; collapsing the deposited quartz rod to prepare a solid elliptical core rod; and sleeving a quartz sleeve on the periphery of the solid elliptical core rod for fusing and stretching to obtain the elliptical core polarization-maintaining optical fiber preform.

Compared with the prior art, the method has simple process, and when the holes which penetrate through the whole quartz rod in a pairwise parallel intersection manner form an ellipse-like structure, the ratio of the long axis and the short axis of the elliptical core can be controlled by controlling the distance between the centers of circles of the holes and the thickness of the core layer deposited in the holes. Compared with the prior art, the method has the advantages of simple process, accurate and controllable proportion of the major axis and the minor axis of the elliptical core, high precision, good stability and capability of obtaining better birefringence.

Drawings

The accompanying drawings, which are included to provide a further understanding of the invention, are incorporated in and constitute a part of this specification. The drawings are not necessarily to scale, however, and may not be intended to accurately reflect the precise structural or performance characteristics of any given embodiment, and should not be construed as limiting or restricting the scope of values or properties encompassed by exemplary embodiments in accordance with the invention. The invention will be described in further detail with reference to the following detailed description and accompanying drawings:

FIG. 1 is a schematic diagram of a conventional elliptical core polarization maintaining fiber production process;

fig. 2 is a schematic view of an intermediate structure of the present invention, which shows that 2 holes are formed on a quartz rod and deposition is performed.

FIG. 3 is a schematic cross-sectional view of a second embodiment of an elliptical core polarization maintaining optical fiber preform of the present invention, in which 3 holes are formed in a quartz rod and deposited;

FIG. 4 is a schematic cross-sectional view of a collapsed elliptical core polarization maintaining optical fiber preform of the present invention;

FIG. 5 is a schematic cross-sectional view of an elliptical core polarization maintaining fiber obtained after a quartz sleeve is sleeved on the outer periphery of an elliptical core polarization maintaining fiber preform according to the present invention.

Detailed Description

The embodiments of the present invention are described below with reference to specific embodiments, and other advantages and technical effects of the present invention will be fully apparent to those skilled in the art from the disclosure in the specification. The invention is capable of other embodiments and of being practiced or of being carried out in various ways, and its several details are capable of modification in various respects, all without departing from the general spirit of the invention. It is to be noted that the features in the following embodiments and examples may be combined with each other without conflict. The following exemplary embodiments of the present invention may be embodied in many different forms and should not be construed as limited to the specific embodiments set forth herein. It is to be understood that these embodiments are provided so that this disclosure will be thorough and complete, and will fully convey the technical solutions of these exemplary embodiments to those skilled in the art.

The first embodiment;

preparing a quartz rod, and symmetrically forming two holes which penetrate through the whole quartz rod and are intersected pairwise in parallel along the axis of the quartz rod;

step two, cleaning the quartz rod, heating, extending and thinning the quartz rod to a required size, and then depositing a core layer;

and step three, referring to fig. 4, after the deposition is finished, the rod is contracted to obtain the elliptical core polarization maintaining optical fiber preform.

Referring to fig. 2, an exemplary quartz rod with a diameter of 40mm and a length of 400mm is selected, 2 holes with a diameter of 10mm are drilled on a quartz rod drilling machine, the drilling depth is 400mm, the circle center b of the hole 1, the circle center c of the hole 2 and the circle center d of the quartz rod are located on the same straight line, the distance bd between the centers of the quartz rod and the hole 1 is equal to the distance cd between the centers of the quartz rod and the hole 2, which is 4mm, and the distance between the centers of the hole 1 and the hole 2 is 8 mm.

Example two;

the invention provides a manufacturing process of an elliptical core polarization maintaining optical fiber preform, which comprises the following steps:

step one, referring to fig. 2, preparing a quartz rod, and forming two parallel and intersected holes penetrating through the whole quartz rod along the axis of the quartz rod;

cleaning the quartz rod, and depositing a core layer on the inner wall of the hole;

step three, as shown in fig. 4, collapsing the deposited quartz rod to form a solid elliptical core rod;

sleeving a quartz sleeve on the periphery of the solid elliptical core rod to enable the circular outer surface of the cladding of the elliptical core rod to be tangent to the inner surface of the quartz sleeve, and then performing melting and stretching treatment to obtain an elliptical core polarization-maintaining optical fiber preform;

referring to fig. 2, an exemplary quartz rod with a diameter of 40mm and a length of 400mm is selected, 2 holes with a diameter of 10mm are drilled on a quartz rod drilling machine, the drilling depth is 400mm, the circle center b of the hole 1, the circle center c of the hole 2 and the circle center d of the quartz rod are located on the same straight line, the distance bd between the centers of the quartz rod and the hole 1 is equal to the distance cd between the centers of the quartz rod and the hole 2, which is 4mm, and the distance between the centers of the hole 1 and the hole 2 is 8 mm.

Example three;

preparing a quartz rod, and symmetrically forming three holes which penetrate through the whole quartz rod and are intersected in pairs in parallel along the axis of the quartz rod;

step two, cleaning the quartz rod, heating, extending and thinning the quartz rod to a required size, and then depositing a core layer;

and step three, referring to fig. 4, after the deposition is finished, the rod is contracted to obtain the elliptical core polarization maintaining optical fiber preform.

Referring to fig. 3, an exemplary quartz rod with a diameter of 40mm and a length of 400mm is selected, and 3 holes with a diameter of 10mm are drilled on a quartz rod drilling machine, wherein the drilling depth is 400mm, the circle center b of the hole 1, the circle center c of the hole 2, the circle center a of the hole 3, and the circle center d of the quartz rod are located on the same straight line, the circle center d of the quartz rod overlaps the circle center a of the hole 3, and the circle center distance ab of the hole 1 and the hole 3 is equal to the circle center distance ac of the hole 2 and the hole 3, which are both 8 mm.

Example four;

the invention provides a manufacturing process of an elliptical core polarization maintaining optical fiber preform, which comprises the following steps:

preparing a quartz rod, and symmetrically forming three holes which penetrate through the whole quartz rod and are intersected in pairs in parallel along the axis of the quartz rod;

cleaning the quartz rod, and depositing a core layer on the inner wall of the hole;

step three, as shown in fig. 4, collapsing the deposited quartz rod to form a solid elliptical core rod;

sleeving a quartz sleeve on the periphery of the solid elliptical core rod to enable the circular outer surface of the cladding of the elliptical core rod to be tangent to the inner surface of the quartz sleeve, and then performing melting and stretching treatment to obtain an elliptical core polarization-maintaining optical fiber preform;

referring to fig. 3, an exemplary quartz rod with a diameter of 40mm and a length of 400mm is selected, and 3 holes with a diameter of 10mm are drilled on a quartz rod drilling machine, wherein the drilling depth is 400mm, the circle center b of the hole 1, the circle center c of the hole 2, the circle center a of the hole 3, and the circle center d of the quartz rod are located on the same straight line, the circle center d of the quartz rod overlaps the circle center a of the hole 3, and the circle center distance ab of the hole 1 and the hole 3 is equal to the circle center distance ac of the hole 2 and the hole 3, which are both 8 mm.

Optionally, the first embodiment or the second embodiment is further improved, the same parts are not repeated, the circle center of the quartz rod and the circle centers of all the through holes on any radial section are all located on the same straight line, and the distance between the circle centers of the adjacent holes is smaller than the sum of the radii of the two holes.

Example five;

further improvement is made on the basis of the first embodiment to the fourth embodiment, the same parts are not repeated, the ellipticity of the elliptical core is controlled by controlling the distance between the centers of the circles punched, and the ratio range of the major axis to the minor axis of the elliptical core is 2: 1 to 6: 1.

example six;

further improvement is made on the basis of the second embodiment or the fourth embodiment, the same parts are not repeated, and the circular outer surface of the elliptical core rod cladding is tangent to the inner surface of the quartz sleeve.

Example seven;

the invention provides an elliptical core polarization-maintaining optical fiber preform manufactured by the manufacturing process of the elliptical core polarization-maintaining optical fiber preform in any one of the first embodiment to the sixth embodiment.

An eighth embodiment;

the invention provides a manufacturing process of an elliptical core polarization maintaining optical fiber by using the manufacturing process of an elliptical core polarization maintaining optical fiber preform rod, which further comprises the following steps:

and drawing the elliptical core polarization maintaining optical fiber preform into a bare optical fiber with a required size, and coating inner layer and outer layer coatings on the surface of the bare optical fiber to obtain the elliptical core polarization maintaining optical fiber.

Example nine;

referring to fig. 5, the present invention provides an elliptical core polarization maintaining fiber manufactured by the manufacturing process of the elliptical core polarization maintaining fiber according to the eighth embodiment.

The present invention has been described in detail with reference to the specific embodiments, which are only the preferred embodiments of the present invention and are not intended to limit the present invention. Equivalent alterations and modifications made by those skilled in the art without departing from the principle of the invention should be considered to be within the technical scope of the invention.