Low-loss optical transmission wire core optical fiber and preparation method thereof

Abstract

The invention discloses a low-loss optical transmission wire core optical fiber which comprises an outer sleeve, the outer sleeve is provided with a plurality of sections, a fiber section piece is arranged between every two adjacent sections of the outer sleeve, the middle part of each fiber section piece is set to be in a photonic crystal fiber transmission mode, and the center part of each fiber section piece is connected with a quartz rod in a penetrating mode. The inner edge part of the fiber section sheet is connected with an inner sleeve in a penetrating manner, the outer sleeve, the fiber section sheet, the inner sleeve and the quartz rod are preheated and melted into a whole in a vacuum environment of a wire drawing tower, and then wire drawing is performed. The whole wire core optical fiber has the structural characteristic of a bamboo joint, the central nano wire is convenient to fix, subsequent welding and wire drawing are more convenient, the fiber joints are designed to be in a photonic crystal fiber transmission mode, light enters the fiber joints after being transmitted from the nano wire, the light is transmitted at the fiber joints in the photonic crystal fiber transmission mode, and the light transmission efficiency is improved. And then the signal enters the wire core optical fiber from the photonic crystal optical fiber, so that the signal transmission is more stable, and the low loss is ensured.

Description

Technical Field

[0001] The present invention relates to the field of optical fiber technology, and in particular to a low-loss light transmission core optical fiber and a preparation method thereof. Background Art

[0002] The structure of traditional solid-core quartz optical fiber mainly consists of a core, a cladding, and a coating. The core is made of high-purity quartz glass, and its refractive index is higher than that of the outer cladding. The cladding is made of low-refractive-index quartz glass, which controls the propagation direction of light and prevents light leakage. The coating is added to protect the optical fiber from corrosion by chemicals in the environment, and it also has a certain refractive index, which helps the transmission of light.

[0003] Hollow-core optical fiber is a new type of optical fiber proposed in recent years. Compared with traditional solid-core optical fiber, hollow-core optical fiber can constrain light to propagate in the air of the fiber core through a special glass cladding structure, which gets rid of the limitations of traditional optical fiber materials and realizes the propagation of light in the air along a specific path. It has the advantages of low dispersion, low nonlinearity, high damage threshold, and low transmission loss. However, due to its strict requirements on the outer cladding and wall thickness, and the light is guided by reflection, the transmission of hollow-core optical fiber is very unstable compared with solid-core optical fiber.

[0004] In addition, the emergence and development of various microstructured optical fibers have expanded the properties of optical fibers. Among them, suspended core optical fibers, as a type of microstructured optical fibers, have the characteristics of large-scale, multi-unit light-matter overlapping areas, strong mode field binding capabilities, and sealed and integrated outer layer protection.

[0005] However, in practical applications, the connection between the suspended core fiber and the widely used common single-mode fiber is inevitable, but due to the difference in scale and morphology of the guided mode field of the suspended core fiber and the single-mode fiber, the direct connection between the two usually brings about a large insertion loss. At the same time, the suspended core fiber is mainly drawn by a fiber drawing tower at high temperature from a preform rod of a specific shape, and the central nanowire is directly placed in the outer sleeve, which makes it difficult to fix the central nanowire in position, making it inconvenient to perform subsequent drawing operations, which has an adverse effect on the processing accuracy and efficiency of the optical fiber. Summary of the invention

[0006] In view of the deficiencies in the prior art, the present invention provides a low-loss light transmission silk-core optical fiber and a preparation method thereof. The silk-core optical fiber as a whole has the structural characteristics of a silk core, which is convenient for fixing the central nanowires and for subsequent fusion splicing and drawing.

[0007] The present invention discloses a low-loss optical transmission core optical fiber, comprising an outer sleeve, characterized in that: the outer sleeve is provided with multiple sections, and a fiber section sheet is provided between each two adjacent sections of the outer sleeve;

[0008] The middle part of the fiber segment is set to a photonic crystal fiber transmission mode to form a photonic crystal air hole, and the central part of the photonic crystal air hole is penetrated and connected with a quartz rod;

[0009] The inner edge of the fiber segment sheet is connected through an inner sleeve. The outer sleeve, the fiber segment sheet, the inner sleeve and the quartz rod are preheated and melted into one in a vacuum environment of a drawing tower, and then drawn.

[0010] As a further improvement of the present invention: in two adjacent sections of the outer sleeve, a connector is integrally provided at the bottom of the upper outer sleeve, and a connector slot is opened inside the upper part of the lower outer sleeve. The connector passes through the fiber segment piece and is inserted into the connector slot to form a mortise and tenon structure, thereby splicing multiple sections of the outer sleeve and the fiber segment piece.

[0011] As a further improvement of the present invention: a plurality of string holes are evenly opened on the inner edge of the fiber segment sheet, and the inner sleeve passes through the string holes to string the fiber segment sheets;

[0012] The outer edge of the fiber segment sheet is provided with a through hole corresponding to the adapter and the adapter slot, and the adapter passes through the through hole and is inserted into the inside of the adapter slot.

[0013] As a further improvement of the present invention: the quartz rod becomes a central nanowire after wire drawing. After the central nanowire is connected to the optical signal, the optical signal propagates from the central nanowire and enters the fiber segment, and is transmitted in the form of photonic crystal fiber transmission at the center of the fiber segment; that is, the fiber segment is designed to adopt a photonic crystal fiber transmission mode, the optical signal propagates from the central nanowire and enters the fiber segment, and is transmitted in the form of photonic crystal fiber transmission at the fiber segment, and then enters the central nanowire from the photonic crystal fiber, and this process is repeated.

[0014] The present invention also discloses a method for preparing a low-loss optical transmission core optical fiber, comprising the following steps:

[0015] S1, selecting a plurality of outer sleeves and fiber segments, and splicing the outer sleeves and fiber segments alternately one by one through a core optical fiber splicing device;

[0016] S2, a mortise and tenon structure is formed between each two adjacent sections of the outer sleeves through a connector and a connector slot, and the connector of the upper outer sleeve passes through the through hole of the fiber segment piece and is inserted into the connector slot of the lower outer sleeve to splice multiple sections of the outer sleeves and the fiber segment piece;

[0017] S3, after the plurality of sections of the outer sleeve and the fiber segment sheet are spliced, the inner sleeve is inserted into the corresponding string holes of the fiber segment sheet; or, the outer sleeve and the fiber segment sheet are inserted into the inner sleeve while being spliced;

[0018] S4, inserting a corresponding quartz rod into the central part of the photonic crystal pore of the fiber segment;

[0019] S5. The outer sleeve, the fiber segment, the inner sleeve and the quartz rod are integrally spliced ​​together to form a preformed rod, the preformed rod is placed in a vacuum environment of a drawing tower to be preheated and melted into one, and finally drawn to form a core optical fiber.

[0020] The present invention also discloses another method for preparing a low-loss optical transmission core optical fiber, comprising the following steps:

[0021] S1, selecting a plurality of outer sleeves and fiber segment sheets, and placing the outer sleeves and fiber segment sheets alternately in a stacked manner;

[0022] S2, inserting the stacked outer sleeves and fiber segment sheets into corresponding inner sleeves;

[0023] Alternatively, the outer sleeve and the fiber segment sheet are inserted into the inner sleeve while being spliced;

[0024] S3, inserting a corresponding quartz rod into the central part of the fiber segment;

[0025] S4, splicing the outer sleeve, the fiber segment sheet, the inner sleeve and the quartz rod as a whole to form a preformed rod, placing the preformed rod into a metal sleeve, and then placing the metal sleeve in a drawing tower graphite furnace, evacuating the furnace, and heating the furnace at a temperature of 200° C.;

[0026] S5, applying pressure in the upper and lower directions of the preform rod at the same time, so that bonding reaction occurs between various parts of the preform rod;

[0027] S6. After the bonding reaction is completed, the metal sleeve is removed to form a preformed rod that is integrated after bonding, and finally drawn through a drawing tower.

[0028] As a further improvement of the present invention: the core optical fiber splicing equipment is arranged above the drawing tower; when in use, the outer sleeve and the fiber segment piece are first alternately introduced into the shaping tube in the core optical fiber splicing equipment, and then the outer sleeve and the fiber segment piece are spliced ​​inside the shaping tube, so as to facilitate the subsequent insertion of the inner sleeve and the quartz rod into the outer sleeve and the fiber segment piece.

[0029] As a further improvement of the present invention: the core optical fiber splicing device comprises a housing and a receiving plate;

[0030] The receiving plate is fixedly installed inside the shell, and a loading mechanism is arranged on one side thereof, and the loading mechanism comprises a material discharging plate frame and a multi-joint material taking manipulator;

[0031] The material discharging plate frame is fixedly mounted on the receiving plate, the multi-joint material picking robot is located above the material discharging plate frame and is fixedly mounted on the inner wall of the outer shell, the outer sleeve and the fiber segment sheet are placed in the material discharging plate frame, and the material is picked up by the multi-joint material picking robot.

[0032] As a further improvement of the present invention: the receiving plate is further provided with a material guiding mechanism, the material guiding mechanism comprising an electrically controlled telescopic arm, an inner telescopic rod, a material suction plate and a rotating plate;

[0033] The rotating material tray is rotatably arranged on the receiving plate, and the electrically controlled telescopic arm is located above the rotating material tray and fixedly installed on the inner wall of the housing;

[0034] The telescopic end of the electric-controlled telescopic arm is hollow, the fixed end of the inner telescopic rod is fixedly connected inside the telescopic end of the electric-controlled telescopic arm, and the suction plate is fixedly installed on the telescopic end of the inner telescopic rod.

[0035] As a further improvement of the present invention: the rotating material tray includes a material trough, a material rack, a connecting trough, a spring and a photoelectric sensor;

[0036] The material troughs are provided with at least eight, evenly arranged on the edge of the rotating material tray, and the electrical sensor is fixedly installed above the material troughs;

[0037] A plurality of connecting grooves connected to the material trough are horizontally arranged on the inner wall of each material trough. One end of the material rack is exposed inside the material trough, and the other end is elastically fixed inside the connecting groove by the spring.

[0038] As a further improvement of the present invention: a clamping mechanism is arranged below the receiving plate, and the clamping mechanism comprises a groove plate frame, a through hole, a slide seat, a slide rail, a connecting frame, a hoop, a rack plate and a driving gear;

[0039] A pipe end joint corresponding to the position of the connecting groove on the transfer plate is fixedly installed below the receiving plate, and one end of the shaping pipe passes through the through hole inside the groove plate frame and is sleeved outside the pipe end joint;

[0040] The slide seats are provided in two groups and are fixedly mounted on both sides of the connecting groove, and the slide rails are slidably connected to the slide seats;

[0041] The hoop is fixed to a hook-shaped connecting frame, the connecting frame and the hoop are centrally symmetrically distributed on the other two sides of the connecting groove, and one end of the connecting frame is fixed to one end of the slide rail;

[0042] The rack plate is fixed to the other end of the slide rail, the driving gear is meshed and connected between the two rack plates, and the driving gear is driven by a driving motor, which is fixed and inverted below the receiving plate.

[0043] Compared with the prior art, the present invention has the following beneficial effects:

[0044] The silk core optical fiber of the present invention, through the arrangement of the fiber segment pieces, makes the preform rod as a whole have the structural characteristics of the silk core, which is convenient for subsequent welding and drawing, and thus more convenient for fixing the central nanowire (made by drawing the quartz rod) after the drawing process.

[0045] The silk core optical fiber of the present invention has a fiber node designed as a photonic crystal fiber transmission mode. Light propagates from the nanowires and enters the fiber node, where it is transmitted in the form of a photonic crystal fiber transmission. Then, it enters the silk core optical fiber from the photonic crystal fiber, which makes signal transmission more stable and ensures low loss. BRIEF DESCRIPTION OF THE DRAWINGS

[0046] Figure 1 It is a schematic diagram of the main structure of the outer sleeve and the fiber segment.

[0047] Figure 2 Schematic diagram of the cross-sectional structure of the silk-core optical fiber.

[0048] Figure 3 Schematic diagram of the cross-sectional structure of the fiber segment.

[0049] Figure 4 It is a schematic diagram of the main cross-sectional structure of the outer sleeve, fiber segment, inner sleeve, quartz rod and other components.

[0050] Figure 5 It is a schematic diagram of the main cross-sectional structure of two adjacent outer sleeves with mortise and tenon structures.

[0051] Figure 6 It is a schematic diagram of the main cross-sectional structure in which the outer sleeve, fiber segment, inner sleeve and quartz rod are placed in the metal sleeve.

[0052] Figure 7 This is a schematic diagram of the main structure of the drawing tower and the core optical fiber splicing equipment.

[0053] Figure 8 Schematic diagram of the internal structure of the core optical fiber splicing equipment.

[0054] Fig. 9 It is a schematic diagram of the top view of the rotating material tray.

[0055] Fig.10 It is a schematic diagram of the main cross-sectional structure of the rotating material tray.

[0056] Fig.11 It is a schematic diagram of the top view of the clamping mechanism.

[0057] Fig.12 This is the total loss curve of the fundamental mode of the core optical fiber of the present invention as the wavelength changes.

[0058] In the figure:

[0059] 1. Outer sleeve; 101. Connector; 102. Connector slot; 103. Inner sleeve; 2. Fiber segment; 201. Through hole; 202. String hole; 203. Photonic crystal pore; 3. Quartz rod; 4. Drawing tower; 5. Fiber core splicing equipment; 501. Outer shell; 502. Adapter plate; 503. Pipe end joint; 6. Feeding mechanism; 601. Feeding plate rack; 602. And multi-joint material taking manipulator; 7. Material guiding mechanism; 701. Electric Control telescopic arm; 702, inner telescopic rod; 7021, suction plate; 703, rotating plate; 7031, material trough; 7032, material rack; 7033, connecting groove; 7034, spring; 7035, photoelectric sensor; 8, clamping mechanism; 801, groove plate rack; 802, through hole; 803, slide seat; 804, slide rail; 805, connecting frame; 806, clamping hoop; 807, rack plate; 808, driving gear; 9, shaping tube. DETAILED DESCRIPTION

[0060] In order to make the purpose, technical solution and advantages of the embodiments of the present invention clearer, the technical solution in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0061] The present invention is further described in detail below in conjunction with the accompanying drawings:

[0062] Embodiment 1:

[0063] See also Figure 1 to Figure 5 A core optical fiber comprises an outer sleeve 1, which is provided with multiple sections, and a fiber segment piece 2 is provided between each two adjacent sections of the outer sleeve 1; in the two adjacent sections of the outer sleeve 1, a connector 101 is integrally provided at the bottom of the lower outer sleeve 1, and a connecting slot 102 is provided at the top of the upper outer sleeve 1, and a through hole 201 corresponding to the connector 101 and the connecting slot 102 is provided at the outer edge of the fiber segment piece 2, and the connector 101 of the upper outer sleeve 1 passes through the through hole 201 and is inserted into the connecting slot 102 of the lower outer sleeve 1 to form a mortise and tenon structure, thereby realizing the upper and lower splicing of the multiple sections of the outer sleeve 1 and the fiber segment piece 2.

[0064] The middle part of the fiber segment 2 is configured as a photonic crystal fiber transmission mode to form a photonic crystal pore 203, and the central part of the photonic crystal pore 203 is penetrated and connected with a quartz rod 3; the quartz rod 3 becomes a central nanowire after wire drawing, and after the central nanowire is connected to the optical signal, the optical signal enters the fiber segment 2 after propagating through the central nanowire, and is transmitted in the form of photonic crystal fiber transmission at the center of the fiber segment 2, and then enters the central nanowire from the photonic crystal fiber, and repeats this process.

[0065] The inner edge of the fiber segment piece 2 is connected with the inner sleeve 103, and the outer sleeve 1, the fiber segment piece 2, the inner sleeve 103 and the quartz rod 3 are preheated and melted into one in the vacuum environment of the drawing tower, and then drawn. Furthermore, the inner edge of the fiber segment piece 2 is evenly opened with a plurality of string holes 202, and the inner sleeve 103 passes through the string holes 202 to connect the fiber segment piece 2 in series.

[0066] It should be particularly noted that the quartz rod 3 can be equivalently replaced by any other material that can be made into optical fiber, such as plastic material, photosensitive resin, etc., that is, the fiber segment 2 provided by the present invention can be added to any existing optical fiber made of any material.

[0067] The solution in this embodiment can be selectively combined with the solutions in other embodiments for use.

[0068] Embodiment 2:

[0069] See also Figure 1-5 Based on the above embodiments, the present invention further provides a method for preparing a core optical fiber, comprising:

[0070] S1, select a multi-section outer sleeve 1 and a fiber segment piece 2, and splice the outer sleeve 1 and the fiber segment piece 2 alternately up and down; the specific splicing method is: a mortise and tenon structure is formed between each two adjacent sections of the outer sleeve 1 through a connector 101 and a connector slot 102, and the connector 101 of the upper outer sleeve 1 passes through the through hole 201 of the fiber segment piece 2 and is inserted into the connecting slot 102 of the lower outer sleeve 1, so as to splice the multi-section outer sleeve 1 and the fiber segment piece 2;

[0071] S2, after the multi-section outer sleeve 1 and the fiber segment piece 2 are spliced, the inner sleeve 103 is inserted into the corresponding upper and lower string holes 202 of the fiber segment piece 2; or, during the splicing process of the multi-section outer sleeve 1 and the fiber segment piece 2, the inner sleeve 103 is simultaneously inserted into the string holes 202 of the fiber segment piece 2;

[0072] S3, inserting the corresponding quartz rod 3 into the central part of the photonic crystal air hole 203 of the fiber segment 2;

[0073] S4, the outer sleeve 1, the fiber segment 2, the inner sleeve 103 and the quartz rod 3 are integrally spliced ​​together to form a preform rod, the preform rod is placed in a vacuum environment of a drawing tower 4 to be preheated and melted into one, and finally drawn to form a core optical fiber.

[0074] It should be noted that the specific dimensions of the core optical fiber can be processed as follows: the diameter of the outer sleeve 1 is 125 microns, and the wall thickness is 10 microns; the diameter of the inner sleeve 103 is 31 or 28 microns, and the wall thickness is 0.5 microns; the diameter of the central nanowire is about 0.4 microns.

[0075] Note: The size of the preform rod is a proportional enlargement of the core optical fiber. For example, if the diameter of the optical fiber is 125 microns, the diameter of the preform rod can be 12.5 cm.

[0076] The thickness of the fiber segment 2 in the preform rod is set to about 10 microns, and the spacing between adjacent fiber segment pieces 2 is set to 0.5 mm. The pulled out optical fiber has a fiber segment pulling the central nanowire every 500 meters; after being drawn into optical fiber, the thickness of the fiber segment of the preform rod is 1 meter; the diameter of the photonic crystal air channel at the fiber segment is about 3.5 microns, and the air channel spacing is about 7 microns.

[0077] During the drawing process, 0.3-2 MPa of air pressure is applied to the optical fiber through the unsealed air hole 203 at the end face of the photonic crystal; the optical fiber is then subjected to a first heating treatment, and the optical fiber is subjected to a first stretching, the air pressure applied to the optical fiber after the first stretching is reduced to 0.11-0.5 MPa, the optical fiber is subjected to a second heating treatment, and during the second heating process, a second stretching is performed to form a suspended core type online optical fiber micro unit with a micro-nano core diameter. The stretching speed of the first stretching is 1.2 mm / min and / or the stretching speed of the second stretching is 15 mm / min.

[0078] The solution in this embodiment can be selectively combined with the solutions in other embodiments for use.

[0079] Embodiment 3:

[0080] See also Figure 1-6 Based on the above embodiment, the embodiment of the present invention further provides another method for preparing a core optical fiber, which is specifically as follows:

[0081] S1, (cancel the joint head 101 and the joint slot 102 to form a mortise and tenon structure) select multiple outer sleeves 1 and fiber segment pieces 2, and alternately stack the outer sleeves 1 and the fiber segment pieces 2;

[0082] S2, inserting the stacked outer sleeve 1 and the fiber segment piece 2 into the corresponding inner sleeve 103; or, inserting the outer sleeve 1 and the fiber segment piece 2 into the inner sleeve 103 while splicing them;

[0083] S3, inserting the corresponding quartz rod 3 into the central part of the photonic crystal air hole 203 of the fiber segment 2;

[0084] S4, the outer sleeve 1, the fiber segment sheet 2, the inner sleeve 103 and the quartz rod 3 are integrally spliced ​​to form a preformed rod, the preformed rod is placed in a metal sleeve, and the metal sleeve is placed in a drawing tower graphite furnace, evacuated, and heated at a temperature of 200° C.;

[0085] S5, applying pressure in the upper and lower directions of the preform rod at the same time, so that bonding reaction occurs between various parts of the preform rod;

[0086] S5. After the bonding reaction is completed, the metal sleeve is removed to form a preformed rod that is integrated after bonding, and finally the preform is drawn through a drawing tower.

[0087] The solution in this embodiment can be selectively combined with the solutions in other embodiments for use.

[0088] Embodiment 4:

[0089] See also Figure 7-11 On the basis of the above embodiment, a core optical fiber splicing device 5 is arranged above the drawing tower 4, and the multi-section outer sleeve 1 and the fiber segment piece 2 are spliced ​​through the core optical fiber splicing device 5; the outer sleeve 1 and the fiber segment piece 2 are first alternately introduced into the shaping tube 9 in the core optical fiber splicing device 5, and then the outer sleeve 1 and the fiber segment piece 2 are spliced ​​inside the shaping tube 9, so as to facilitate the subsequent insertion of the inner sleeve 103 and the quartz rod 3 into the outer sleeve 1 and the fiber segment piece 2.

[0090] In this embodiment, the core optical fiber splicing device 5 includes an outer shell 501 and a receiving plate 502; the receiving plate 502 is fixedly installed inside the outer shell 501, and a loading mechanism 6 is arranged on one side thereof, and the loading mechanism 6 includes a feeding plate rack 601 and a multi-joint feeding robot 602; the feeding plate rack 601 is fixedly installed on the receiving plate 502, the multi-joint feeding robot 602 is located above the feeding plate rack 601, and is fixedly installed on the inner wall of the outer shell 501, the outer sleeve 1 and the fiber segment piece 2 are placed in the feeding plate rack 601, and the material is taken by the multi-joint feeding robot 602; the outer sleeve 1 and the fiber segment piece 2 are neatly placed inside the feeding plate rack 601 by stacking or installing them in other ways, and the outer sleeve 1 and the fiber segment piece 2 are alternately clamped by the multi-joint feeding robot 602 to the rotating disk 703 of the material guide mechanism 7; that is, after clamping an outer sleeve 1, it is reset, and then a fiber segment piece 2 is clamped, and this is repeated.

[0091] Furthermore, in this embodiment, a material guiding mechanism 7 is also provided on the receiving plate 502, and the material guiding mechanism 7 includes an electrically controlled telescopic arm 701, an inner telescopic rod 702, a material suction plate 7021 and a rotating plate 703; the rotating plate 703 is rotatably arranged on the receiving plate 502, and the electrically controlled telescopic arm 701 is located above the rotating plate 703 and is fixedly mounted on the inner wall of the outer shell 501; the rotating plate 703 can automatically rotate according to the material picking situation of the multi-joint material picking robot 602, and an electrical signal connection is established between the two. When the multi-joint material picking robot 602 clamps any material (outer sleeve 1 or fiber segment 2) to the rotating plate 703, the rotating plate 703 automatically rotates to a preset angle. The telescopic end of the electric-controlled telescopic arm 701 is hollow, the fixed end of the inner telescopic rod 702 is fixedly connected to the inside of the telescopic end of the electric-controlled telescopic arm 701, and the suction plate 7021 is fixedly installed on the telescopic end of the inner telescopic rod 702; the structure of the telescopic end of the electric-controlled telescopic arm 701 is similar to the cylindrical structure, so that the fixed end of the inner telescopic rod 702 can be fixedly installed inside the telescopic end of the electric-controlled telescopic arm 701.

[0092] Furthermore, in the present embodiment, the rotating material tray 703 includes a material trough 7031, a material rack 7032, a connecting groove 7033, a spring 7034 and a photoelectric sensor 7035; the material trough 7031 is connected from top to bottom and is provided with at least eight, which are evenly arranged on the edge of the rotating material tray 703, and the photoelectric sensor 7035 is fixedly installed above the material trough 7031; through the setting of the photoelectric sensor 7035, it is possible to identify whether the material (the outer sleeve 1 or the fiber segment 2) is placed on the material trough 7031 of the rotating material tray 703; when the photoelectric sensor 7035 detects that there is material placed on the material trough 7031 of the rotating material tray 703, the rotating material tray 703 automatically rotates to a preset angle, and the preset angle is the angle between the two material troughs 7031; at the same time, the multi-joint material picking robot 602 is reset to prepare for the next material to be picked up. A plurality of connecting grooves 7033 connected to the material trough 7031 are horizontally arranged on the inner wall of each material trough 7031. One end of the material rack 7032 is exposed inside the material trough 7031, and the other end is elastically fixed inside the connecting groove 7033 by a spring 7034. A chamfer is arranged above the exposed end of the material rack 7032, and the material rack 7032 can be pushed into the connecting groove 7033 under the action of external force.

[0093] Furthermore, in this embodiment, a clamping mechanism 8 is arranged below the receiving plate 502, and the clamping mechanism 8 includes a groove plate frame 801, a through hole 802, a slide seat 803, a slide rail 804, a connecting frame 805, a clamp 806, a rack plate 807 and a driving gear 808; a pipe end joint 503 corresponding to the position of the loading trough 7031 of the rotating disk 703 is fixedly installed below the receiving plate 502, and one end of the shaping tube 9 passes through the through hole 802 inside the groove plate frame 801 and is sleeved on the outside of the pipe end joint 503, and the shaping tube 9 is connected through the pipe end joint 503, so as to facilitate the material to enter the shaping tube 9.

[0094] There are two sets of slides 803, which are fixedly installed on both sides of the trough 7031, and the slide rail 804 is slidably connected to the slide 803; the hoop 806 is fixed to the hook-shaped connecting frame 805, and the connecting frame 805 and the hoop 806 are symmetrically distributed on the other two sides of the trough 7031, and one end of the connecting frame 805 is fixed to one end of the slide rail 804; the rack plate 807 is fixed to the other end of the slide rail 804, and the driving gear 808 is meshed and connected between the two rack plates 807. In the process, a driving motor is set to drive the active gear 808, and the driving motor is fixed and inverted under the receiving plate 502; the driving motor drives the active gear 808 to rotate, and the active gear 808 drives the rack plates 807 and the slide rails 804 on both sides thereof to move in opposite directions on the slide seat 803, so that the clamp 806 and the connecting frame 805 also move in opposite directions, and then the clamp 806 can tightly clamp the end of the shaping tube 9 on the tube end joint 503 on the left and right sides.

[0095] The specific method of using the present invention includes:

[0096] 1) When the material is placed inside the trough 7031, the photoelectric sensor 7035 can recognize that the material (the outer sleeve 1 or the fiber segment 2) is placed on the rotating material tray 703. When the photoelectric sensor 7035 detects that there is material placed on the trough 7031 of the rotating material tray 703, the rotating material tray 703 automatically rotates an angle of the trough 7031, and the multi-joint material taking manipulator 602 is reset, ready to wait for the next material to be taken;

[0097] 2) After the rotating material disc 703 automatically rotates an angle of the material trough 7031, the electric-controlled telescopic arm 701 receives the rotation signal of the rotating material disc 703 and extends downward. Since the inside of the telescopic end of the electric-controlled telescopic arm 701 is set as a hollow structure, the structure of the telescopic end of the electric-controlled telescopic arm 701 becomes a cylinder, so that it can be extended into the material trough 7031 and sleeved on the outside of the material. The telescopic end of the electric-controlled telescopic arm 701 can form a contact with the material rack 7032;

[0098] 3) When the telescopic end of the electric telescopic arm 701 touches the material rack 7032, the inner telescopic rod 702 moves downward and extends, sucks the material through the suction plate 7021, and then retracts into the telescopic end of the electric telescopic arm 701 while carrying the material;

[0099] 4) Then the electrically controlled telescopic arm 701 continues to descend, carrying the material and squeezing the material rack 7032 at the same time, pushing the material rack 7032 into the connecting groove 7033, and then passing through the material groove 7031 into the pipe end joint 503, and then into the shaping tube 9. Finally, the inner telescopic rod 702 extends its length to push the material into the shaping tube 9 for placement, or squeezes and stacks the existing material inside the shaping tube 9. Finally, the electrically controlled telescopic arm 701 and the inner telescopic rod 702 retract and return to their original position to place the material on the lower wheel, thereby stacking the material inside the shaping tube 9.

[0100] 5) After stacking, the multi-section outer sleeve 1 and the fiber segment piece 2 are spliced ​​inside the shaping tube 9 to form a whole, and the driving motor drives the driving gear 808 to reverse, and the driving gear 808 drives the rack plate 807 and the slide rail 804 on both sides thereof to move in opposite directions on the slide seat 803, so that the clamp 806 can be opened on both sides, so that the end of the shaping tube 9 is not clamped on the tube end joint 503;

[0101] 6) Manually or automatically insert the inner sleeve 103 and the quartz rod 2 into the multi-segment outer sleeve 1 and the fiber segment sheet 2, and then remove the shaping tube 9 to form a preformed rod; finally, the preformed rod is placed in the drawing tower 4 to prepare for drawing.

[0102] It should be particularly pointed out that, no matter the outer sleeve 1 has a connector and a connector slot or not, the multi-joint material picking robot 602 can clamp the material and place the material vertically into the material trough 7031 of the rotating material tray 703 .

[0103] The solution in this embodiment can be selectively combined with the solutions in other embodiments for use.

[0104] like Fig.12 As shown, at 1550 nm, the total loss of the fundamental mode of the low-loss light transmission core optical fiber does not exceed 0.005 dB / km.

[0105] The above are only preferred embodiments of the present invention and are not intended to limit the present invention. For those skilled in the art, the present invention may have various modifications and variations. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention shall be included in the protection scope of the present invention.

Claims

1. A low-loss optical transmission core optical fiber, comprising an outer sleeve (1), characterized in that: The outer sleeve (1) is provided with a plurality of sections, and a fiber segment sheet (2) is provided between every two adjacent sections of the outer sleeve (1); The middle part of the fiber segment (2) is configured as a photonic crystal optical fiber transmission mode to form a photonic crystal air hole (203), and the central part of the photonic crystal air hole (203) is penetrated and connected with a quartz rod (3); The inner edge of the fiber segment sheet (2) is connected through an inner sleeve (103). The outer sleeve (1), the fiber segment sheet (2), the inner sleeve (103) and the quartz rod (3) are preheated and melted into one in a vacuum environment of a drawing tower, and then drawn.

2. The low-loss optical transmission core optical fiber according to claim 1, characterized in that: In two adjacent sections of the outer sleeve (1), a connector (101) is integrally provided at the bottom of the upper outer sleeve (1), and a connector slot (102) is provided at the top of the lower outer sleeve (1). The connector (101) passes through the fiber segment piece (2) and is inserted into the connector slot (102) to form a mortise and tenon structure, thereby splicing multiple sections of the outer sleeve (1) and the fiber segment piece (2).

3. The low-loss optical transmission core optical fiber according to claim 2, characterized in that: The inner edge of the fiber segment sheet (2) is evenly provided with a plurality of string holes (202), and the inner sleeve (103) passes through the string holes (202) to string the fiber segment sheets (2); The outer edge portion of the fiber segment sheet (2) is provided with a through hole (201) corresponding to the adapter (101) and the adapter slot (102); the adapter (101) passes through the through hole (201) and is inserted into the inside of the adapter slot (102).

4. The low-loss optical transmission core optical fiber according to claim 1, characterized in that: The quartz rod (3) becomes a central nanowire after wire drawing. After the central nanowire is connected to an optical signal, the optical signal propagates from the central nanowire and enters the fiber segment (2), and is transmitted in the form of photonic crystal optical fiber at the center of the fiber segment (2).

5. A method for preparing a low-loss optical transmission core optical fiber as claimed in any one of claims 1 to 4, characterized in that: The following steps are involved: S1, selecting a plurality of sections of outer sleeves (1) and fiber segments (2), and splicing the outer sleeves (1) and fiber segments (2) alternately section by section using a core optical fiber splicing device (5); S2, a mortise and tenon structure is formed between each two adjacent sections of the outer sleeve (1) through a connector (101) and a connector slot (102), and the connector (101) of the upper outer sleeve (1) passes through the through hole (201) of the fiber segment piece (2) and is inserted into the connector slot (102) of the lower outer sleeve (1), so as to splice multiple sections of the outer sleeve (1) and the fiber segment piece (2); S3, after the plurality of sections of the outer sleeve (1) and the fiber segment sheet (2) are spliced ​​together, the inner sleeve (103) is inserted into the corresponding string hole (202) of the fiber segment sheet (2); or, the outer sleeve (1) and the fiber segment sheet (2) are inserted into the inner sleeve (103) while being spliced ​​together; S4, inserting a corresponding quartz rod (3) into the central part of the photonic crystal air hole (203) of the fiber segment (2); S5, the outer sleeve (1), the fiber segment (2), the inner sleeve (103) and the quartz rod (3) are integrally spliced ​​to form a preform rod, the preform rod is placed in a vacuum environment of a drawing tower (4) to be preheated and melted into one, and finally drawn to form a core optical fiber.

6. The method for preparing a low-loss optical transmission core optical fiber according to claim 5, characterized in that: The core optical fiber splicing device (5) is arranged above the drawing tower (4); when in use, the outer sleeve (1) and the fiber segment piece (2) are first introduced alternately into the shaping tube (9) in the core optical fiber splicing device (5), and then the outer sleeve (1) and the fiber segment piece (2) are spliced ​​inside the shaping tube (9).

7. The method for preparing a low-loss optical transmission core optical fiber according to claim 6, characterized in that: The core optical fiber splicing device (5) comprises a housing (501) and a receiving plate (502); The receiving plate (502) is fixedly mounted inside the housing (501), and a loading mechanism (6) is provided on one side thereof, wherein the loading mechanism (6) comprises a material discharging plate frame (601) and a multi-joint material taking manipulator (602); The material discharging plate frame (601) is fixedly mounted on the receiving plate (502), the multi-joint material picking robot (602) is located above the material discharging plate frame (601) and is fixedly mounted on the inner wall of the outer shell (501), the outer sleeve (1) and the fiber segment sheet (2) are placed in the material discharging plate frame (601), and the material is picked up by the multi-joint material picking robot (602).

8. The method for preparing a low-loss optical transmission core optical fiber according to claim 7, characterized in that: The receiving plate (502) is also provided with a material guiding mechanism (7), and the material guiding mechanism (7) comprises an electrically controlled telescopic arm (701), an inner telescopic rod (702), a material suction plate (7021) and a rotating plate (703); The rotating material tray (703) is rotatably arranged on the receiving plate (502), and the electrically controlled telescopic arm (701) is located above the rotating material tray (703) and is fixedly installed on the inner wall of the housing (501); The telescopic end of the electrically controlled telescopic arm (701) is hollow, the fixed end of the inner telescopic rod (702) is fixedly connected inside the telescopic end of the electrically controlled telescopic arm (701), and the suction plate (7021) is fixedly mounted on the telescopic end of the inner telescopic rod (702).

9. The method for preparing a low-loss optical transmission core optical fiber according to claim 8, characterized in that: The rotating material tray (703) comprises a material trough (7031), a material rack (7032), a connecting groove (7033), a spring (7034) and a photoelectric sensor (7035); The material troughs (7031) are provided with at least eight, evenly arranged on the edge of the rotating material tray (703), and the electrical sensor (7035) is fixedly installed above the material troughs (7031); A plurality of connecting grooves (7033) connected to the material trough (7031) are horizontally arranged on the inner wall of each material trough (7031); one end of the material rack (7032) is exposed inside the material trough (7031), and the other end is elastically fixed inside the connecting groove (7033) by the spring (7034).

10. The method for preparing a low-loss optical transmission core optical fiber according to claim 9, characterized in that: A clamping mechanism (8) is provided below the receiving plate (502), and the clamping mechanism (8) comprises a groove plate frame (801), a through hole (802), a slide seat (803), a slide rail (804), a connecting frame (805), a hoop (806), a rack plate (807) and a driving gear (808); A pipe end joint (503) corresponding to the position of the connecting groove (7033) on the rotating disc (703) is fixedly installed below the receiving plate (502), and one end of the shaping tube (9) passes through the through hole (802) inside the groove plate frame (801) and is sleeved on the outside of the pipe end joint (503); The slide seats (803) are provided in two groups and are fixedly mounted on both sides of the connecting groove (7033), and the slide rails (804) are slidably connected to the slide seats (803); The hoop (806) is fixed to a hook-shaped connecting frame (805), the connecting frame (805) and the hoop (806) are centrally symmetrically distributed on the other two sides of the connecting groove (7033), and one end of the connecting frame (805) is fixed to one end of the slide rail (804); The rack plate (807) is fixed to the other end of the slide rail (804), and the driving gear (808) is meshed and connected between the two rack plates (807). The driving gear (808) is driven by a driving motor, and the driving motor is fixed and inverted below the receiving plate (502).

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