CN212770472U

CN212770472U - Linear polarization-maintaining optical fiber preform

Info

Publication number: CN212770472U
Application number: CN202020612928.6U
Authority: CN
Inventors: 汪杰; 赵霞; 徐丹; 朱婷婷; 严伟; 曹兵; 张冬梅
Original assignee: Jiangsu Fasten Optoelectronics Technology Co ltd; Wuxi Fasten Photoelectric Technology Co ltd; Fasten Group Co Ltd
Current assignee: Jiangsu farsheng Photoelectric Technology Co., Ltd
Priority date: 2020-04-22
Filing date: 2020-04-22
Publication date: 2021-03-23
Anticipated expiration: 2030-04-22

Abstract

The utility model relates to a style of calligraphy polarization maintaining optical fiber perform, including plug, stress rod, pure quartz stick and the pure quartz sleeve of surrounding layer, plug, stress rod and pure quartz stick are all polished into the cylindrical stick that the diameter is d1, d2, d 3. The core rod, the stress rod and the pure quartz rod are arranged and placed in the pure quartz sleeve with the outer cladding layer to assemble the linear polarization-maintaining optical fiber perform. The utility model discloses still relate to a manufacturing approach of style of calligraphy polarization maintaining fiber. The utility model discloses single stick drawing optical fiber length is long, and the optic fibre of preparation possesses characteristics such as stress action district area is little and the parameter is even, and the utility model relates to a manufacturing method is simple.

Description

Linear polarization-maintaining optical fiber preform

Technical Field

The utility model relates to an optical fiber sensing technology field especially relates to a style of calligraphy polarization maintaining optical fiber perform.

Background

The polarization maintaining optical fiber transmits linearly polarized light, and in an interference optical fiber sensor based on optical coherence detection, the polarization maintaining optical fiber can ensure that the linear polarization direction is unchanged, and the coherent signal-to-noise ratio is improved, so that high-precision measurement of physical quantity to be measured is realized. At present, the large-scale commercial polarization maintaining optical fiber in the world mainly comprises a panda type, an elliptical jacket type, a bow tie type and an elliptical type. The first three belong to stress-to-partial type, and the latter belong to geometric shape-to-partial type.

Among the three kinds of medium-stress polarization maintaining fibers, the bow-shaped polarization maintaining fiber has a smaller stress area relative to a panda polarization maintaining fiber, so that better environmental adaptability is shown, namely, better temperature stability is achieved, and the bow-shaped polarization maintaining fiber is more suitable for being applied to a high-precision optical fiber gyroscope.

In the prior art, chinese patent document CN1632629A discloses a "straight" polarization maintaining fiber and a method for producing the same, wherein an inner deposition method is used to sequentially deposit an outer cladding layer, a stress region, an inner cladding layer and a core region. The substrate tube is internally communicated with fluorine-containing corrosive gas, and a fire head or two fire heads burning at two sides of the substrate tube move back and forth along the axial direction of the substrate tube to enable the substrate tube to be etched, but not completely etched through and to have certain thickness. And forming the I-shaped polarization maintaining optical fiber prefabricated rod through a subsequent collapsing process. The utility model has the main limitation that the shape of the stress area is formed by flame etching, and the consistency among batches is difficult to ensure; secondly, the linear polarization-maintaining optical fiber perform rod is prepared by one-step forming through an in-tube deposition method, the diameter of the pipe is limited due to the limitation of flame energy, the prepared linear polarization-maintaining optical fiber perform rod is too small, the drawing length of a single rod is small, and the axial uniformity of optical fibers is difficult to ensure.

SUMMERY OF THE UTILITY MODEL

The utility model aims to solve the technical problem that a style of calligraphy polarization maintaining optical fiber perform is provided to above-mentioned prior art, can solve current "a" style of calligraphy polarization maintaining optical fiber because it is few to take single stick wire drawing length that intraductal deposit and directional etching method caused in the production process, the poor problem of optic fibre axial homogeneity and batch uniformity.

The utility model provides a technical scheme that above-mentioned problem adopted does: the utility model provides a style of calligraphy polarization maintaining optical fiber perform, includes plug, stress stick, pure quartz stick and the pure quartz sleeve of surrounding layer, plug, stress stick and pure quartz stick polish into cylindrically, plug, stress stick and pure quartz stick diameter d1 d2 d3, the pure quartz sleeve internal diameter of surrounding layer is d 0.

According to the scheme, the core rod, the stress rod and the pure quartz rod are arranged into a regular hexagon and are placed in the pure quartz sleeve with the outer cladding layer.

According to the scheme, the number of the core rods is 1, the core rods are placed in the center of the outer cladding pure quartz sleeve, the number of the stress rods is n1, the stress rods are arranged in 3 rows and are tightly arranged on the core rods, the number of the pure quartz rods is n2, and the stress rods, the core rods and the stress rods are arranged into a regular hexagon. n1, n2 satisfies the relation (n1/3+1) × d1 ═ d0, n1+ n2+31 ═ 11(d0/d 1).

According to the scheme, the length a of the stress region is d0 (n1/3+1) d1, the width b of the stress region is 3d1, and the ratio of a to b is 3-8.

Preferably, the number of the core rods is 1, the number of the stress rods n1 is 30, the number of the pure quartz rods n2 is 60, and the ratio of a/b is 11/3.

The utility model provides a manufacturing method of a style of calligraphy polarization maintaining fiber, contain following step:

(1) manufacturing a core rod, and polishing the core rod into a cylinder with the cross section diameter of d 1;

(2) manufacturing a stress rod, and grinding or extending the stress rod into a cylinder with the cross section diameter d 2;

(3) polishing or extending a pure quartz rod into a cylinder with the cross-sectional diameter d 3;

(4) cleaning the polished core rod, stress rod and pure quartz rod, arranging the core rod, stress rod and pure quartz rod into a regular hexagon, placing the regular hexagon in a pure quartz sleeve to form a linear polarization-maintaining optical fiber preform;

(5) and (2) drawing the linear polarization-maintaining optical fiber perform to thin the linear polarization-maintaining optical fiber perform into a quartz optical fiber, wherein during drawing, the tail end of the perform is connected with a glass extension tube with the same outer diameter and the wall thickness of about 2-5 mm, the other end of the glass tube is sealed, the linear polarization-maintaining optical fiber perform is vacuumized at the same time, the vacuum degree is 0-200 mBar, and two layers of acrylic resin optical fiber coatings are coated on the outer surface of the drawn quartz optical fiber.

Compared with the prior art, the utility model has the advantages of:

1) the utility model relates to a style of calligraphy polarization maintaining optical fiber perform, the stick footpath can reach more than 80mm, and single stick drawing optical fiber length is long, and the axial homogeneity of optic fibre is better.

2) The utility model relates to a "one" style of calligraphy polarization maintaining optical fiber that a style of calligraphy polarization maintaining optical fiber perform produced, its stress action district is a style of calligraphy, and the area in stress action district is little, has good temperature adaptability, and this stress action district shape obtains through machining's mode, and control accuracy is high, and batch uniformity is good.

3) The utility model provides a pair of a word polarization maintaining fiber manufacturing approach, its process flow is simple, realizes the degree height nature.

Drawings

Fig. 1 is a schematic cross-sectional view of an optical wand according to an embodiment of the present invention.

Fig. 2 is a schematic cross-sectional view of an optical fiber according to an embodiment of the present invention.

Wherein: 1. the core rod, 2, stress rod, 3, pure quartz rod, 4, pure quartz sleeve, 5, fiber core, 6 stress area, and 7, outer cladding.

Detailed Description

The present invention will be described in further detail with reference to the following embodiments.

A first embodiment of a linear polarization maintaining optical fiber preform according to the present invention has a cross-sectional structure as shown in fig. 1. In the illustrated embodiment, the I-shaped polarization maintaining optical fiber preform comprises 1 core rod 1, 30 stress rods 2, 60 pure quartz rods 3 and an outer cladding pure quartz sleeve 4. The core rod, the stress rod and the pure quartz rod are all polished into a cylinder shape. The center of the core rod is superposed with the pure quartz sleeve with the outer cladding layer, the stress rods are arranged into three rows and are tightly arranged into 3 rows, and the core rod, the stress rods and the pure quartz rods are arranged into a regular hexagon and are placed in the pure quartz sleeve to form the linear polarization-maintaining optical fiber prefabricated rod.

The method for preparing the linear polarization maintaining optical fiber by using the linear polarization maintaining optical fiber preform rod comprises the following steps:

step (1): manufacturing a core rod, and polishing the core rod into a cylinder with the cross section diameter of d 1;

step (2): manufacturing stress rods, grinding or extending the stress rods into a cylinder with the cross section diameter d2, wherein the number of the stress rods is 30;

and (3): polishing or extending pure quartz rods into a cylinder with the cross section diameter d3 for 60 pieces;

and (4): cleaning the polished core rods, stress rods and pure quartz rods, and arranging the core rods, the stress rods and the pure quartz rods into a regular hexagon, wherein the number of the stress rods is three, 10 are respectively arranged at the upper part, the middle part and the lower part, the core rods are positioned at the central position of the stress rod at the middle layer, the pure quartz rods are positioned at the upper side and the lower side of the stress layer, and 30 are respectively arranged at each side, and the core rods, the stress rods and the pure quartz rods arranged in the manner are placed in a pure quartz sleeve to form a linear polarization-maintaining optical fiber preform;

and (5): and (2) drawing the linear polarization-maintaining optical fiber perform to thin the linear polarization-maintaining optical fiber perform into a quartz optical fiber, wherein during drawing, the tail end of the perform is connected with a glass extension tube with the same outer diameter and the wall thickness of about 2-5 mm, the other end of the glass tube is sealed, simultaneously, the linear polarization-maintaining optical fiber perform is vacuumized, the vacuum degree is 0-200 mBar, and two layers of acrylic resin optical fiber coatings are coated on the outer surface of the drawn quartz optical fiber.

The cross-section of the drawn fiber is shown in FIG. 2, where the core 5 is centered on the outer cladding 7 and the stress regions 6 are symmetrically located on either side of the core 5.

In addition to the above embodiments, the present invention also includes other embodiments, and all technical solutions formed by equivalent transformation or equivalent replacement should fall within the protection scope of the claims of the present invention.

Claims

1. The utility model provides a style of calligraphy polarization maintaining optical fiber perform, includes plug (1), a plurality of stress stick (2), a plurality of pure quartz stick (3) and outer cladding pure quartz sleeve (4), its characterized in that: the core rod (1), the stress rods (2) and the pure quartz rods (3) are arranged in the pure quartz sleeve (4) to form a regular polygon, the core rod (1) is located at the center of the regular polygon, and the stress rods (2) form a stress area.

2. The in-line polarization maintaining optical fiber preform of claim 1, wherein: the core rod (1), the stress rod (2) and the pure quartz rod (3) are ground into a cylinder, the diameter d1 of the core rod, the diameter d2 of the stress rod and the diameter d3 of the pure quartz rod are d0, and the inner diameter of the outer cladding pure quartz sleeve is d 0.

3. The in-line polarization maintaining optical fiber preform of claim 1, wherein: the core rods (1), the stress rods (2) and the pure quartz rods (3) are arranged into a regular hexagon.

4. The in-line polarization maintaining optical fiber preform of claim 2, wherein: the number of the core rods (1) is 1, the core rods are positioned in the center of the pure quartz sleeve (4), the number of the stress rods (2) is n1, the core rods are arranged into 3 rows, the core rods are positioned in the center of the stress rod on the middle layer, the number of the pure quartz rods (3) is n2, the pure quartz rods are symmetrically distributed on the upper side and the lower side of the stress layer, and the core rods, the stress rods and the pure quartz rods which are arranged in the mode are placed in the pure quartz sleeve.

5. The in-line polarization maintaining optical fiber preform of claim 4, wherein: the number n1 of the stress rods (2) satisfies the relation (n1/3+1) d 1-d 0, and the number n2 of the pure quartz rods (3) satisfies the relation n1+ n2+ 31-11 (d0/d 1).

6. The in-line polarization maintaining optical fiber preform of claim 4, wherein: the stress region length a is d0 (n1/3+1) d1, the stress region width b is 3d1, and the ratio of a to b is 3-8.