A low-loss optical transmission core optical fiber and its preparation method

Abstract

The present invention discloses a low-loss optical transmission core fiber, comprising an outer sleeve, the outer sleeve being provided with multiple sections, a fiber segment being provided between each two adjacent sections of the outer sleeve, the middle portion of the fiber segment being provided in a photonic crystal fiber transmission mode, and the central portion thereof being connected through a quartz rod, the inner edge portion of the fiber segment being connected through an inner sleeve, the outer sleeve, the fiber segment, the inner sleeve and the quartz rod being preheated and melted into one piece in a vacuum environment of a drawing tower, and then being drawn. The core fiber as a whole has the structural characteristics of a bamboo node, which facilitates the fixing of the central nanofilament and is also more convenient for subsequent fusion splicing and drawing. The fiber segment is designed to be transmitted in a photonic crystal fiber mode, and light propagates from the nanofilament into the fiber segment, where it is transmitted in the form of a photonic crystal fiber transmission, and then enters the core fiber from the photonic crystal fiber, thus making signal transmission more stable and ensuring low loss.

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 quartz glass with a low refractive index, 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 fiber is a new type of optical fiber introduced in recent years. Compared to traditional solid-core fiber, hollow-core fiber uses a special glass cladding structure to confine light propagation in the air within the fiber core. This breaks away from the limitations of traditional optical fiber materials and allows light to propagate through the air along a specific path. It offers advantages such as low dispersion, low nonlinearity, a high damage threshold, and low transmission loss. However, due to strict requirements for the outer cladding and wall thickness, and its reliance on reflection to guide light, the transmission of hollow-core fiber is highly unstable compared to solid-core fiber.

[0004] In addition, the emergence and development of various microstructured optical fibers have expanded the characteristics 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 ability, and sealed and integrated outer layer protection.

[0005] However, in practical applications, connecting suspended core fibers to widely used conventional single-mode fibers is unavoidable. However, due to differences in the scale and morphology of the guided mode fields of suspended core fibers and single-mode fibers, direct connection between the two typically results in significant insertion loss. Furthermore, suspended core fibers are primarily produced by drawing a preform of a specific shape at high temperatures in a fiber drawing tower. The central nanofilament is placed directly within the outer sleeve, making it difficult to secure the central nanofilament in place, hindering subsequent drawing operations and negatively impacting the processing accuracy and efficiency of the fiber. Summary of the Invention

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

[0007] The present invention discloses a low-loss light transmission core optical fiber, comprising an outer sleeve, characterized in that: the outer sleeve is provided with multiple sections, and a fiber segment is provided between every 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 the 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] A through hole corresponding to the adapter and the adapter slot is formed on the outer edge of the fiber segment sheet, and the adapter is inserted into the adapter slot through the through hole.

[0013] As a further improvement of the present invention: the quartz rod becomes a central nanowire after being drawn. 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 at the center of the fiber segment in the form of photonic crystal fiber transmission; that is, the fiber segment is designed to adopt a photonic crystal fiber transmission mode, and the optical signal propagates from the central nanowire and enters the fiber segment, and is transmitted at the fiber segment in the form of photonic crystal fiber transmission, 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 multiple sections of outer sleeves and fiber segments, and splicing the outer sleeves and fiber segments one by one alternately using 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 multiple sections of the outer sleeve and the fiber segment sheet are spliced together, 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 together;

[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, fiber segment, inner sleeve and quartz rod are integrally spliced together to form a preform rod, the preform 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. Select multiple outer sleeves and fiber segment sheets, and alternately stack the outer sleeves and fiber segment sheets;

[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 together;

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

[0025] S4. Assemble the outer sleeve, fiber segment, inner sleeve and quartz rod to form a preform, place the preform in a metal sleeve, and then place the metal sleeve in a drawing tower graphite furnace, evacuate the furnace, and heat it at 200° C.

[0026] S5. Simultaneously applying pressure in the upper and lower directions of the preform rod to cause bonding reaction between various parts of the preform rod;

[0027] S6. After the bonding reaction is completed, the metal sleeve is removed to form a preform 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 includes a housing and a receiving plate;

[0030] The receiving plate is fixedly mounted inside the housing, and a loading mechanism is provided on one side thereof, the loading mechanism comprising a material discharging plate rack and a multi-joint material taking manipulator;

[0031] The unloading plate rack is fixedly mounted on the receiving plate, the multi-joint material picking robot is located above the unloading plate rack and is fixedly mounted on the inner wall of the shell, the outer sleeve and fiber segment sheet are placed in the unloading plate rack, 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 mounted on the receiving plate, and the electrically controlled telescopic arm is located above the rotating material tray and fixedly mounted 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 to the inside of 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 groove, a spring and a photoelectric sensor;

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

[0037] A plurality of communication slots 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 communication slot by the spring.

[0038] As a further improvement of the present invention: a clamping mechanism is provided below the receiving plate, and the clamping mechanism includes 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 material trough of the rotating material tray is fixedly installed under the receiving plate, and one end of the shaping pipe passes through the through hole inside the groove plate frame and is sleeved on the outside of the pipe end joint;

[0040] The slide seats are provided in two groups and are fixedly mounted on both sides of the through hole, 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 symmetrically distributed on the other two sides of the through hole, 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 core optical fiber of the present invention has the structural characteristics of a core by setting the fiber segment pieces, so that the preform rod as a whole has the structural characteristics of a 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 to adopt a photonic crystal fiber transmission mode. Light propagates from the nanowire and enters the fiber node, where it is transmitted in the form of a photonic crystal fiber, and then enters the silk-core optical fiber from the photonic crystal fiber. This 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 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 and quartz rod.

[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 This is a schematic diagram of the main cross-sectional structure of the outer sleeve, fiber segment, inner sleeve and quartz rod placed in the metal sleeve.

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

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

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

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

[0056] Figure 11 It is a schematic diagram of the top structure of the clamping mechanism.

[0057] Figure 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 picture:

[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. Fiber drawing tower; 5. Fiber core splicing equipment; 501. Outer shell; 502. Adapter plate; 503. Tube end connector; 6. Loading mechanism; 601. Unloading plate rack; 602. Multi-joint material retrieving manipulator; 7. Material guide 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] To make the objectives, technical solutions, and advantages of the embodiments of the present invention more clear, the technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the accompanying 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 making creative efforts shall fall within the scope of protection of the present invention.

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

[0062] Example 1:

[0063] See also Figures 1 to 5 A core optical fiber includes an outer sleeve 1, which is provided with multiple sections. 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. 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. 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 multiple sections of the outer sleeve 1 and the fiber segment piece 2.

[0064] The middle part of the fiber segment 2 is configured to adopt a photonic crystal fiber transmission mode to form a photonic crystal pore 203, and a quartz rod 3 is connected to the central part of the photonic crystal pore 203; the quartz rod 3 is drawn into a central nanofilament, and when the central nanofilament is connected to an optical signal, the optical signal propagates through the central nanofilament and enters the fiber segment 2, where it is transmitted in the form of a photonic crystal fiber transmission at the center of the fiber segment 2, and then enters the central nanofilament from the photonic crystal fiber, and this process is repeated.

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

[0066] It should be 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 sheet 2 provided by the present invention can be added to existing optical fibers of all materials.

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

[0068] Example 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 multiple outer sleeves 1 and fiber segment pieces 2, and splice the outer sleeves 1 and fiber segment pieces 2 alternately up and down. The specific splicing method is: each adjacent outer sleeve 1 is connected by a connector 101 and a connecting slot 102 to form a mortise and tenon structure, 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 to splice the multiple outer sleeves 1 and fiber segment piece 2;

[0071] S2. After the multi-section outer sleeve 1 and the fiber segment piece 2 are spliced together, 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 center 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, and 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 outer sleeve 1 has a diameter of 125 microns and a wall thickness of 10 microns; the inner sleeve 103 has a diameter of 31 or 28 microns and a wall thickness of 0.5 microns; and 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. When the optical fiber is pulled out, there is 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 spacing between the air channels is about 7 microns.

[0077] During the drawing process, an air pressure of 0.3-2 MPa is applied to the optical fiber through the unsealed air holes 203 at the end face of the photonic crystal. The optical fiber is then subjected to a first heating treatment and 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 then 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 having a micro-nano core diameter. The first stretching speed is 1.2 mm / min and / or the second stretching speed is 15 mm / min.

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

[0079] Example 3:

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

[0081] S1, (cancel the joint 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 fiber segment pieces 2;

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

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

[0084] S4. Assemble the outer sleeve 1, the fiber segment 2, the inner sleeve 103, and the quartz rod 3 to form a preform rod, place the preform rod into a metal sleeve, and then place the metal sleeve in a drawing tower graphite furnace, evacuate the furnace, and heat it at 200° C.

[0085] S5. Simultaneously applying pressure in the upper and lower directions of the preform rod to cause bonding reaction between various parts of the preform rod;

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

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

[0088] Example 4:

[0089] See also Figure 7-11 On the basis of the above embodiment, a core optical fiber splicing device 5 is provided 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 provided on one side thereof, the loading mechanism 6 includes a discharge plate rack 601 and a multi-joint material picking robot 602; the discharge plate rack 601 is fixedly installed on the receiving plate 502, the multi-joint material picking robot 602 is located above the discharge 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 discharge plate rack 601, and the material is picked up by the multi-joint material picking robot 602; the outer sleeve 1 and the fiber segment piece 2 are neatly placed inside the discharge plate rack 601 by stacking or installing them in other ways, and the multi-joint material picking robot 602 alternately clamps the outer sleeve 1 and the fiber segment piece 2 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 disc 7021 and a rotating disc 703; the rotating disc 703 is rotatably provided on the receiving plate 502, and the electrically controlled telescopic arm 701 is located above the rotating disc 703 and is fixedly mounted on the inner wall of the outer shell 501; the rotating disc 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 disc 703, the rotating disc 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 this embodiment, the rotating material tray 703 includes a material trough 7031, a material rack 7032, a connecting trough 7033, a spring 7034 and a photoelectric sensor 7035; the material trough 7031 is through-through and is provided with at least eight, 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 can be identified 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, which is the angle between the two material troughs 7031; at the same time, the multi-joint material picking robot 602 is reset, ready to clamp the next material. 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 provided 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 provided below the receiving plate 502, and the clamping mechanism 8 includes a groove plate frame 801, a through hole 802, a slide 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 material plate 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 is connected to the shaping tube 9 through the pipe end joint 503, thereby facilitating 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 through hole 802, 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 through hole 802. 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 meantime, a driving motor is provided to drive the driving gear 808, and the driving motor is fixed and inverted below the receiving plate 502; the driving motor drives the driving gear 808 to rotate, and the driving gear 808 drives the rack plates 807 and the slide rails 804 on both sides thereof to move in opposite directions on the slide 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 pipe 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 the angle of the trough 7031, and the multi-joint material picking robot 602 resets and prepares to wait for the next material to be picked up;

[0097] 2) After the rotating disc 703 automatically rotates through an angle of the trough 7031, the electrically controlled telescopic arm 701 receives the rotation signal of the rotating disc 703 and extends downward. Since the interior of the telescopic end of the electrically controlled telescopic arm 701 is configured as a hollow structure, the structure of the telescopic end of the electrically controlled telescopic arm 701 becomes a cylinder, which can be extended into the trough 7031 and wrapped around the outside of the material. The telescopic end of the electrically controlled telescopic arm 701 can come into 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, sucking 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 while squeezing the material rack 7032, 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. The driving motor drives the driving gear 808 to reverse, and the driving gear 808 drives the rack plates 807 and the slide rails 804 on both sides thereof to move in opposite directions on the slide 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 pipe end joint 503;

[0101] 6) Manually or automatically insert the inner sleeve 103 and the quartz rod 3 into the multi-segment outer sleeve 1 and the fiber segment sheet 2, and then remove the shaping tube 9 to form a preform rod; finally, the preform rod is placed in the drawing tower 4 to prepare for drawing.

[0102] It should be pointed out in particular that, regardless of whether the outer sleeve 1 has a connector and a connector slot or not, the multi-joint material-grabbing 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 Figure 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 merely preferred embodiments of the present invention and are not intended to limit the present invention. Those skilled in the art will readily appreciate that various modifications and variations of the present invention are possible. Any modifications, equivalent substitutions, or improvements made within the spirit and principles of the present invention shall be included within the scope of protection 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 multiple sections, and a fiber segment (2) is provided between every two adjacent sections of the outer sleeve (1); The middle portion of the fiber segment (2) is configured as a photonic crystal fiber transmission mode to form a photonic crystal air hole (203), and the central portion 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), and 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), and 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 being drawn. 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 at the center of the fiber segment (2) in the form of photonic crystal fiber transmission.

5. A method for preparing a low-loss optical transmission core optical fiber according to claim 3, characterized in that: The following steps are involved: S1, selecting multiple sections of outer sleeves (1) and fiber segments (2), and splicing the outer sleeves (1) and fiber segments (2) alternately one by one 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 holes (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 portion of the photonic crystal pore (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 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.

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 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).

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. The loading mechanism (6) includes 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 manipulator (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 manipulator (602).

8. The method for preparing a low-loss optical transmission core optical fiber according to claim 7, wherein: The receiving plate (502) is further 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 disc (7021) and a rotating disc (703); The rotating material tray (703) is rotatably mounted on the receiving plate (502), and the electrically controlled telescopic arm (701) is located above the rotating material tray (703) and is fixedly mounted on the inner wall of the housing (501); The telescopic end of the electric 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 telescopic arm (701), and the suction plate (7021) is fixedly installed 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) includes a material trough (7031), a material rack (7032), a connecting groove (7033), a spring (7034) and a photoelectric sensor (7035); There are at least eight material troughs (7031) evenly arranged on the edge of the rotating material tray (703), and the electrical sensor (7035) is fixedly installed above the material trough (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 upper trough (7031) of the rotating material 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 through hole (802), 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 symmetrically distributed on the other two sides of the through hole (802), 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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