Optical system, optical fiber preparation device and optical fiber preparation method

Abstract

The present application relates to an optical system, an optical fiber preparation device and an optical fiber preparation method, wherein the optical system includes: a first heating system and a second heating system. The first heating system includes a first laser and a first optical path component. The first laser is used to emit a first laser beam, and the first optical path component is used to focus the first laser beam on a raw material rod of the optical fiber preparation device. The second heating system includes a second laser and a second optical path component. The second laser is used to emit a second laser beam, and the second optical path component is used to focus the second laser beam on a position of the raw material rod that has been heated by the first heating system. The optical system provided in the present application can effectively reduce the temperature gradient of the crystallization region during the preparation of the optical fiber, thereby better insulating the optical fiber, reducing the thermal stress generated during the preparation process, thereby reducing the defects of the generated crystal, improving the quality of the single crystal optical fiber, and also improving the stability of the crystallization process.

Description

Technical Field

[0001] The present application relates to the field of material preparation, and in particular to an optical system, an optical fiber preparation device, and an optical fiber preparation method. Background Art

[0002] Single crystal fiber is a single crystal in the form of an optical fiber. Common single crystal fibers on the market include sapphire (Al2O3) fiber, yttrium aluminum garnet (YAG) fiber, etc. Compared with traditional quartz fiber, single crystal fiber has the advantages of high melting point, high thermal conductivity, good infrared transmittance, high damage threshold, and low nonlinear effect. Therefore, single crystal fiber has greatly broadened the application range of traditional optical crystal materials, and has a wide range of applications and important application value in high-power lasers, mid-infrared lasers, high-energy ray detection, high-temperature sensing, etc., especially in ultra-high temperature (above 1400℃) sensing for aircraft engines, single crystal fiber has shown great application prospects.

[0003] The preparation methods of single crystal optical fiber include guided mode method, micro-pull-down method, laser heated pedestal growth (LHPG), etc. Among them, LHPG is one of the most commonly used preparation methods. Compared with other methods, LHPG can achieve the drawing of optical fiber with a diameter of less than 100μm, while other methods are mostly suitable for preparing optical fiber with a diameter of 0.5-2mm.

[0004] LHPG specifically refers to a manufacturing method that uses lasers to focus on the base of raw materials to re-grow crystal materials from the molten raw materials. However, a major feature of LHPG is that the temperature gradient near the melting zone is very high. In the area from the melting zone to the newly grown optical fiber, the temperature gradient can even be as high as 3800℃ / cm. Excessive temperature gradients will bring thermal stress, leading to more crystal defects and unstable growth process. Summary of the invention

[0005] The present application provides an optical system, an optical fiber preparation device and an optical fiber preparation method to solve some or all of the deficiencies in the related art.

[0006] In a first aspect, the present application provides an optical system, which is applied to an optical fiber preparation device, and includes: a first heating system and a second heating system. The first heating system includes a first laser and a first optical path component. The first laser is used to emit a first laser beam, and the first optical path component is used to focus the first laser beam on a raw material rod of the optical fiber preparation device. The second heating system includes a second laser and a second optical path component. The second laser is used to emit a second laser beam, and the second optical path component is used to focus the second laser beam on a position of the raw material rod that has been heated by the first heating system.

[0007] Optionally, the second optical path component includes a lens group. The lens group includes a second shaping lens and a hollow lens. The second shaping lens and the hollow lens are both located on the beam path of the second laser beam. The second shaping lens is used to shape the second laser beam into a ring laser. The hollow lens is used to focus the second laser beam.

[0008] Optionally, the second shaping lens includes two aconical lenses, the plane ends of the two aconical lenses are arranged opposite to each other, the conical end of one aconical lens is arranged in a direction pointing to the second laser, and the conical end of the other aconical lens is arranged in a direction away from the second laser.

[0009] Optionally, the second optical path component further includes a reflector group, which is arranged on the outgoing light beam path of the second shaping lens and is used to reflect the ring laser to the hollow lens.

[0010] Optionally, the reflector group includes a first reflector and a second reflector. The hollow lens includes a first hollow lens and a second hollow lens. The second laser beam is a two-path beam. The first reflector is used to reflect one of the second laser beams to the first hollow lens. The second reflector is used to reflect the other second laser beam to the second hollow lens.

[0011] Optionally, the second optical path component further includes a beam expander lens group, which is arranged on the beam path of the second laser beam and is used to adjust the ring width of the second laser beam.

[0012] Optionally, the second laser beam is a two-way beam; and the beam expander group is used to adjust the spacing distance between the two second laser beams.

[0013] Optionally, the first optical path component includes a first shaping lens, a third reflector and an annular parabolic mirror. The first shaping lens, the third reflector and the annular parabolic mirror are all arranged on the beam path of the first laser beam. The first shaping lens is used to shape the first laser beam into an annular laser. The third reflector is used to reflect the first laser beam emitted by the first shaping lens to the annular parabolic mirror. The annular parabolic mirror is used to focus the first laser beam on the raw material rod.

[0014] In a second aspect, the present application further provides an optical fiber preparation device, comprising a mounting frame, a raw material rod, and an optical system as described in the first aspect. The optical system and the raw material rod are both mounted on the mounting frame. The mounting frame comprises a moving part, which is connected to the raw material rod and is used to drive the raw material rod to move.

[0015] Optionally, in the height direction of the mounting frame, the second focal point of the second laser beam is higher than the first focal point of the first laser beam. In addition, the moving component is used to drive the raw material rod to move in a direction from the first focal point to the second focal point.

[0016] Optionally, the mounting frame includes a panel and a column; the panel includes a first panel and a second panel, the first panel and the second panel are symmetrically arranged along the height direction of the mounting frame, and the first panel is higher than the second panel. The two ends of the plurality of columns are respectively against the first panel and the second panel. The first heating system is arranged between the first panel and the second panel. The second heating system is arranged on a side of the first panel away from the second panel. The first panel includes a focusing hole, and the second panel includes an operation hole. The raw material rod is arranged through the operation hole. The first laser beam is focused on the top of the raw material rod, and the second laser beam passes through the focusing hole and is focused above the raw material rod.

[0017] In a third aspect, the present application also provides a method for preparing an optical fiber, comprising:

[0018] A first laser is used to emit a first laser beam focused on the raw material rod of the optical fiber preparation device, wherein the first laser beam is used to heat the raw material rod and form a single crystal optical fiber;

[0019] A second laser beam focused on the single crystal optical fiber is emitted by a second laser, and the second laser beam is used to heat the single crystal optical fiber.

[0020] Optionally, the first laser beam emitted by the first laser and focused on the raw material rod of the optical fiber preparation device includes:

[0021] shaping the first laser beam into a ring laser by a first shaping lens;

[0022] changing the beam path of the first laser beam by a third reflecting mirror;

[0023] The first laser beam is focused on the top of the raw material rod by an annular parabolic mirror.

[0024] Optionally, emitting a second laser beam focused on the single crystal optical fiber through a second laser comprises:

[0025] The second laser beam is shaped into a ring laser through a lens group and focused on the single crystal optical fiber.

[0026] Optionally, shaping the second laser beam into a ring laser through a lens group and focusing the second laser beam on the single crystal optical fiber comprises:

[0027] shaping the second laser beam into a ring laser by a second shaping lens;

[0028] The second laser beam is focused onto the single crystal optical fiber through a hollow lens.

[0029] Optionally, the step of shaping the second laser beam into a ring laser and focusing the second laser beam on the single crystal optical fiber through a lens group further includes:

[0030] The second shaping lens emits light from the second shaping lens and reflects it to the hollow lens through a reflecting mirror group.

[0031] Optionally, emitting a second laser beam focused on the single crystal optical fiber through a second laser comprises:

[0032] The ring width of the second laser beam is adjusted by a beam expander lens group.

[0033] Optionally, the optical fiber preparation method further comprises:

[0034] The raw material rod is driven by a moving component to move in a direction from a focal point of the first laser beam to a focal point of the second laser beam.

[0035] The technical solution provided by the embodiments of the present application may have the following beneficial effects:

[0036] It can be seen from the above embodiments that the optical system of the present application, through the arrangement of the first heating system and the second heating system, can make the top of the raw material rod first melted by the first laser beam emitted by the first heating system and form a single crystal optical fiber during the preparation process of the optical fiber. Subsequently, the second laser beam emitted by the second heating system is focused on the position of the raw material rod that has been heated by the first heating system. In other words, the second heating system will post-heat the position where the single crystal optical fiber has been formed, thereby reducing the temperature gradient during the preparation process of the optical fiber. It can be seen that the optical system of the present application can effectively reduce the temperature gradient of the crystallization area during the preparation process of the optical fiber, thereby better insulating the optical fiber, reducing the thermal stress generated during the preparation process, thereby reducing the defects of the generated crystal, improving the quality of the single crystal optical fiber, and also improving the stability of the crystallization process.

[0037] It is to be understood that the foregoing general description and the following detailed description are exemplary and explanatory only and are not restrictive of the present application. BRIEF DESCRIPTION OF THE DRAWINGS

[0038] In order to more clearly illustrate the technical solutions in the embodiments of the present application, the drawings required for use in the description of the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without creative work.

[0039] Figure 1 This is a system framework diagram of an optical fiber preparation device in one embodiment of the present application;

[0040] Figure 2 Flow chart of a method for preparing an optical fiber in one embodiment of the present application.

[0041] Description of reference numerals:

[0042] Optical fiber preparation device 100, first heating system 1, first laser 11, first laser beam 111, first optical path component 12, first shaping lens 121, third reflector 122, annular parabolic mirror 123, second heating system 2, second laser 21, second laser beam 211, second optical path component 22, lens group 221, second shaping lens 2211, hollow lens 2212, first hollow lens 2212a, second hollow lens 2212b, reflector group 222, first reflector 222a, second reflector 222b, beam expander group 223, raw material rod 3, mounting frame 4, moving part 41, panel 42, first panel 421, focusing hole 4211, second panel 422, working hole 4221, column 43, single crystal optical fiber 5, first direction X, second direction Y. DETAILED DESCRIPTION

[0043] Here, the technical solutions in the embodiments (or "implementation methods") of the present application will be described clearly and completely in conjunction with the accompanying drawings. When the following description refers to the drawings, unless otherwise indicated, the same numbers in different drawings represent the same or similar elements.

[0044] If there are terms involving directional indications or positional relationships in the embodiments of the present application (such as up, down, left, right, front, back, inside, outside, top, bottom, center, vertical, horizontal, longitudinal, transverse, length, width, counterclockwise, clockwise, axial, radial, circumferential, etc.), such terms are only used to explain the relative positional relationship, movement, etc. between the components under a certain specific posture (as shown in the accompanying drawings); if the specific posture changes, the directional indication or positional relationship will also change accordingly. In addition, the terms "first" and "second" in the embodiments of the present application are only used for the purpose of convenience of description and cannot be understood as indicating or implying relative importance.

[0045] like Figure 1As shown, the present application provides an optical system applied to an optical fiber preparation device 100. The optical system includes: a first heating system 1 and a second heating system 2. The first heating system 1 includes a first laser 11 and a first optical path component 12. The first laser 11 is used to emit a first laser beam 111, and the first optical path component 12 is used to focus the first laser beam 111 on the raw material rod 3 of the optical fiber preparation device 100. The second heating system 2 includes a second laser 21 and a second optical path component 22. The second laser 21 is used to emit a second laser beam 211, and the second optical path component 22 is used to focus the second laser beam 211 on the position of the raw material rod 3 that has been heated by the first heating system 1.

[0046] During the preparation of the optical fiber, the optical system of the present application is provided with the first heating system 1 and the second heating system 2, so that the top of the raw material rod 3 is first melted by the first laser beam 111 emitted by the first heating system 1 and forms a single crystal optical fiber 5. Subsequently, the second laser beam 211 emitted by the second heating system 2 is focused on the position of the raw material rod 3 that has been heated by the first heating system 1. In other words, the second heating system 2 will post-heat the position where the single crystal optical fiber 5 has been formed, thereby reducing the temperature gradient during the preparation of the optical fiber. It can be seen that the optical system provided by the present application can effectively reduce the temperature gradient of the crystallization area during the preparation of the optical fiber, thereby better heat-insulating the optical fiber, reducing the thermal stress generated during the preparation process, thereby reducing the defects of the generated crystal, improving the quality of the single crystal optical fiber 5, and also improving the stability of the crystallization process.

[0047] like Figure 1 As shown, the present application also provides an optical fiber preparation device 100, including a mounting frame 4, a raw material rod 3 and an optical system. The optical system and the raw material rod 3 are both mounted on the mounting frame 4. The mounting frame 4 includes a moving part 41, which is connected to the raw material rod 3 and is used to drive the raw material rod 3 to move.

[0048] As can be seen from the figure, during the preparation process of the optical fiber, the raw material rod 3 is driven by the moving part 41 to move upward along the first direction X, and the first laser beam 111 emitted by the first heating system 1 is focused on the top of the raw material rod 3 to melt and crystallize the raw material rod 3 into a single crystal optical fiber 5. With the continuous driving of the moving part 41, the newly generated single crystal optical fiber 5 will also move upward along the first direction X. At this time, the second laser beam 211 emitted by the second heating system 2 will be focused on the position of the newly generated single crystal optical fiber 5, and the single crystal optical fiber 5 will be post-heated to achieve the effect of heat preservation and reducing the temperature gradient. It can be seen that during the entire preparation process, the first heating system 1 and the second heating system 2 are independent of each other and do not interfere with each other. Under the premise of not affecting the power of the first laser beam 111, the parameters such as the intensity and focusing position of the second laser beam 211 can be arbitrarily adjusted, which effectively improves the flexibility, independence, convenience and adjustment freedom of the optical fiber preparation device 100 during use, so that the operator can more accurately and conveniently adjust the optical fiber preparation device 100 to the ideal temperature field, further ensuring the quality of the prepared optical fiber and the stability during the preparation process.

[0049] In the embodiment disclosed in the present application, the moving part 41 uses a motor as a driving source, and drives the raw material rod 3 to move upward along the first direction X through the extrusion and rotation of the rotating structures on both sides. In addition, in order to further improve the stability during the preparation process, the optical fiber preparation device 100 of the present application is also provided with a moving part 41 at the top of the generated single crystal optical fiber 5, so as to drive the newly generated single crystal optical fiber 5 to move upward along the first direction X. It can be seen that such a structural setting can not only ensure the stability during the preparation process, but also limit the running path of the raw material rod 3 and the single crystal optical fiber 5, ensure the smooth progress of the preparation process and the post-heating process, and ensure the quality of the generated crystal. Of course, in other optional embodiments, the number, installation position and specific structure of the moving part 41 can be set accordingly according to the actual working conditions and the specific needs of the operator, for example: using a manual rocker drive, or using a motor to drive a worm gear mechanism, or using other methods, so this application does not limit this.

[0050] In an optional embodiment, the second optical path component 22 includes a lens group 221. The lens group 221 includes a second shaping lens 2211 and a hollow lens 2212. The second shaping lens 2211 and the hollow lens 2212 are both located on the beam path of the second laser beam 211. The second shaping lens 2211 is used to shape the second laser beam 211 into a ring laser. The hollow lens 2212 is used to focus the second laser beam 211.

[0051] refer to Figure 1It can be seen that after the second laser beam 211 is emitted from the second laser 21, its beam path extends along the second direction Y. After the second laser beam 211 enters the second shaping lens 2211, it will be shaped into a ring laser by the second shaping lens 2211. Subsequently, after the ring-shaped second laser beam 211 enters the hollow lens 2212, it will be focused by the hollow lens 2212 to the surface of the cylindrical single crystal optical fiber 5, thereby performing a heating and heat preservation operation on the single crystal optical fiber 5. It can be seen that the setting of the lens group 221 in the present application enables the second laser beam 211 to be focused on the surface of the cylindrical single crystal optical fiber 5 in the form of a ring laser, so that it can be heated more evenly and comprehensively, and the ring laser can also better avoid laser leakage, further ensuring the safety of the optical fiber preparation device 100. At the same time, the setting of the independent hollow lens 2212 enables the focus point of the second laser beam 211 to be adjusted more freely, thereby improving the adjustment freedom of the optical fiber preparation device 100, and thus enabling the operator to adjust to the ideal temperature field more accurately and conveniently.

[0052] In actual use, the optical fiber preparation device 100 needs to ensure that the beam paths of the first laser beam 111 and the second laser beam 211 are not only aligned with the heating position in height, but also cannot be offset in angle, otherwise it may cause uneven heating, poor quality of the generated single crystal optical fiber 5 and other problems. Therefore, the lenses recorded in this application need to be kept parallel to each other, or perpendicular to each other, or maintain a fixed angle to avoid beam deflection. In order to achieve this goal, each lens recorded in this application has five degrees of freedom. In other words, it can not only move freely in the three directions of X, Y, and Z, but also rotate left and right and pitch along its own axis.

[0053] For example, in Figure 1 In the optional embodiment shown, the second shaping lens 2211 includes two conical lenses, which are arranged in parallel to ensure that the angle of light beam propagation does not change. The hollow lens 2212 and the second shaping lens 2211 are arranged perpendicular to each other, thereby ensuring that the focus position of the second laser beam 211 does not deflect, thereby ensuring the heat preservation effect and optical fiber quality of the post-heating process.

[0054] In an optional embodiment, the plane ends of the two aconical lenses included in the second shaping lens 2211 are arranged opposite to each other. The conical end of one aconical lens is arranged in a direction pointing to the second laser 21, and the conical end of the other aconical lens is arranged in a direction away from the second laser 21.

[0055] In other words, the second laser beam 211 emitted from the second laser 21 will first enter through the conical surface of the first conical lens, and then exit from the plane after transmission. Then, it will enter from the plane end of the second conical lens and exit from the conical surface after transmission. This arrangement can effectively reduce the amount of light reflected back to the second laser 21 by the incident surface of the conical lens, thereby avoiding damage to the second laser 21. Of course, in some other embodiments, a protective component to prevent laser damage can also be set inside the laser, so that the two conical lenses can be set in a manner where the conical surfaces are arranged relative to each other. Therefore, this application does not limit this.

[0056] In general, the coordinated setting of the two conical lenses can better shape the second laser beam 211 into a ring laser, thereby more evenly focusing on the single crystal optical fiber 5, and avoiding laser leakage, etc. In addition, before the optical fiber preparation device 100 starts working, the angle of the laser beam is adjusted to a suitable position by adjusting the setting angle of the two conical lenses; during use, the parameters such as the ring diameter of the second laser beam 211 can be adjusted by adjusting the spacing between the lenses, thereby further improving the adjustment freedom of the optical system.

[0057] In an optional embodiment, the second optical path component 22 further includes a reflector group 222 , which is disposed on the outgoing light beam path of the second shaping lens 2211 and is used to reflect the ring laser to the hollow lens 2212 .

[0058] The second laser beam 211 emitted by the second laser 21 first extends along the second direction Y, and after entering the reflector group 222, its beam path changes to extend downward along the first direction X, and then enters the hollow lens 2212 for focusing. It can be seen that the setting of the reflector group 222 can better coordinate the second laser 21, the beam path of the second laser beam 211, the focus point position and the running direction of the single crystal optical fiber 5, so that the various components of the optical fiber preparation device 100 do not interfere with each other, and also make the first heating system 1 and the second heating system 2 independent of each other, ensuring the independent control of the two heating systems, and improving the adjustment freedom of the optical system.

[0059] In the embodiment disclosed in the present application, the reflector group 222 uses an annular reflector, so that the second laser beam 211 that has been shaped into an annular laser can be better reflected, ensuring that the second laser beam 211 can be more accurately focused and heated more evenly during the post-heating process. In other optional embodiments, it is also possible not to use structures such as shaping lenses and annular reflectors, that is, directly using ordinary plane reflectors to reflect and focus the laser beam. This setting method is simpler and less costly, but it may also cause part of the laser to leak through the hole in the center of the reflector. Therefore, the present application does not limit this.

[0060] In an optional embodiment, the reflector group 222 includes a first reflector 222a and a second reflector 222b. The hollow lens 2212 includes a first hollow lens 2212a and a second hollow lens 2212b. The second laser beam 211 is a two-way beam. The first reflector 222a is used to reflect one of the second laser beams 211 to the first hollow lens 2212a. The second reflector 222b is used to reflect the other second laser beam 211 to the second hollow lens 2212b.

[0061] After the two second laser beams 211 emitted from the second laser 21 pass through the shaping lens, they are reflected to the first hollow lens 2212a and the second hollow lens 2212b by the first reflector 222a and the second reflector 222b, respectively. Such a structural setting enables the two laser beams to form a complete ring, so that the single crystal optical fiber 5 can be post-heated more evenly. At the same time, it can be seen from the figure that a hole is left between the first reflector 222a and the second reflector 222b, and a hole is also left between the first hollow lens 2212a and the second hollow lens 2212b. The setting of these holes facilitates the upward movement of the newly crystallized single crystal optical fiber 5 along the first direction X, avoids interference between the single crystal optical fiber 5 and the components of the optical fiber preparation device 100, ensures the smooth progress of the preparation and post-heating process, and also ensures the stability and safety of the optical fiber preparation device 100 during operation.

[0062] In an optional embodiment, the second optical path component 22 further includes a beam expander lens group 223 , which is disposed on the beam path of the second laser beam 211 and is used to adjust the ring width of the second laser beam 211 .

[0063] In the actual preparation process, the ring width of the second laser beam 211 after shaping is changed by adjusting the beam expansion ratio of the beam expander group 223. Specifically, if the beam expansion ratio of the beam expander group 223 to the second laser beam 211 is larger, the ring width of the ring laser after subsequent shaping is wider. It can be seen that the setting of the beam expander group 223 also effectively improves the adjustment freedom of the optical fiber preparation device 100, further facilitates the operator to adjust to the ideal temperature field, and improves the crystallization quality and stability during the preparation process.

[0064] In actual use scenarios, the beam expander lens group 223 generally includes two lenses or two reflector groups, and a more complex lens group may also be used. Therefore, it should be particularly noted that the present application does not limit the specific structure of the beam expander lens group 223, but as described above, the use of two lenses, reflectors, or a combination of multiple lenses and reflectors to achieve beam expansion of the second laser beam 211 and adjustment of the ring width of the ring laser are all within the scope of the present application.

[0065] In an optional embodiment, the second laser beam 211 is a two-path beam; the beam expander lens group 223 is used to adjust the spacing distance between the two second laser beams 211 .

[0066] As described above, the second laser beam 211 emitted by the second laser 21 is two beams. By adjusting the spacing between the two laser beams, the ring width of the second laser beam 211 after being shaped by the second shaping lens 2211 can be changed. This adjustment method has a higher degree of freedom and greater convenience, allowing the operator to adjust the laser beam faster, more conveniently and more accurately.

[0067] In an optional embodiment, the first optical path component 12 includes a first shaping lens 121, a third reflector 122, and an annular parabolic mirror 123. The first shaping lens 121, the third reflector 122, and the annular parabolic mirror 123 are all arranged on the beam path of the first laser beam 111. Among them, the first shaping lens 121 is used to shape the first laser beam 111 into an annular laser. The third reflector 122 is used to reflect the first laser beam 111 emitted by the first shaping lens 121 to the annular parabolic mirror 123. The annular parabolic mirror 123 is used to focus the first laser beam 111 on the raw material rod 3.

[0068] Similar to the second heating system 2 described above, the first laser beam 111 emitted from the first laser 11 has a beam path extending along the second direction Y, and after passing through the first shaping lens 121, it will be shaped into a ring laser; then after being reflected by the third reflector 122, the beam path becomes to extend upward along the first direction X; finally, after entering the annular parabolic mirror 123, it is focused on the top of the raw material rod 3, thereby heating the raw material rod 3. It can be seen that the first heating system 1 also has a high degree of adjustment freedom, and is independent of the second heating system 2 and does not interfere with each other, ensuring the convenience and accuracy of the operator during use.

[0069] In an optional embodiment, in the height direction of the mounting frame 4, the second focal point of the second laser beam 211 is higher than the first focal point of the first laser beam 111. In addition, the moving component 41 is used to drive the raw material rod 3 to move in the direction from the first focal point to the second focal point.

[0070] In other words, in the first direction X, the focus point of the second laser beam 211 is above the focus point of the first laser beam 111, so that the first laser beam 111 heats the raw material rod 3 to generate the single crystal optical fiber 5, and the second laser beam 211 heats and keeps the crystallized single crystal optical fiber 5 warm to reduce the temperature gradient. At the same time, the raw material rod 3 moves upward along the first direction X, so that new single crystal optical fibers 5 can be crystallized continuously, forming a complete set of optical fiber preparation process.

[0071] In an optional embodiment, the mounting frame 4 includes a panel 42 and a column 43; the panel 42 includes a first panel 421 and a second panel 422, the first panel 421 and the second panel 422 are symmetrically arranged along the height direction of the mounting frame 4, and the first panel 421 is higher than the second panel 422. The two ends of the plurality of columns 43 are respectively against the first panel 421 and the second panel 422. The first heating system 1 is arranged between the first panel 421 and the second panel 422. The second heating system 2 is arranged on the side of the first panel 421 away from the second panel 422. Among them, the first panel 421 includes a beam hole 4211, and the second panel 422 includes an operation hole 4221. The raw material rod 3 is arranged through the operation hole 4221. The first laser beam 111 is focused on the top of the raw material rod 3, and the second laser beam 211 passes through the beam hole 4211 and is focused on the top of the raw material rod 3.

[0072] Similarly, the term "higher than" described here means that along the first direction X, the first panel 421 is arranged above the second panel 422, and the column 43 is arranged between the first panel 421 and the second panel 422, which plays a role in improving the stability of the mounting frame 4. The first heating system 1 is arranged between the first panel 421 and the second panel 422, and is focused on the top of the raw material rod 3 after being shaped and reflected by the first optical path component 12. The second heating system 2 is arranged above the first panel 421, and is also focused on the top of the raw material rod 3, that is, the surface of the single crystal optical fiber 5 after being expanded, shaped, and reflected by the second optical path component 22. It can be seen from the figure that the focusing hole 4211 can not only ensure that the second laser beam 211 is smoothly focused on the single crystal optical fiber 5, but also prevent the single crystal optical fiber 5 from colliding with the first panel 421 during the upward movement along the first direction X. The setting of the operation hole 4221 ensures that the raw material rod 3 can move upward along the first direction X through the second panel 422, avoiding the collision between the raw material rod 3 and the second panel 422. It can be seen that the structural setting of the mounting frame 4 ensures the smooth progress of the optical fiber preparation process, and further ensures the stability and safety of the preparation process.

[0073] like Figure 2 As shown, the present application also provides a method for preparing an optical fiber, which is performed by the optical fiber preparation device 100 described above. The optical fiber preparation method includes:

[0074] S1, emitting a first laser beam 111 focused on the raw material rod 3 of the optical fiber preparation device through the first laser 11, the first laser beam 111 is used to heat the raw material rod 3 and form a single crystal optical fiber 5;

[0075] S2 , emitting a second laser beam 211 focused on the single crystal optical fiber 5 through the second laser 21 , where the second laser beam 211 is used to heat the single crystal optical fiber 5 .

[0076] In the optical fiber preparation method, the first laser 11 and the second laser 21 are respectively emitted by the first laser 11 and the second laser 21, so that the top of the raw material rod 3 is first melted by the first laser beam 111 and forms a single crystal optical fiber 5. Subsequently, the second laser beam 211 is focused on the position of the raw material rod 3 that has been heated by the first heating system 1, that is, the position where the single crystal optical fiber 5 has been formed is post-heated, thereby reducing the temperature gradient in the optical fiber preparation process. It can be seen that the optical fiber preparation method can effectively reduce the temperature gradient of the crystallization region during the preparation of the optical fiber, thereby better insulating the optical fiber, reducing the thermal stress generated during the preparation process, thereby reducing the defects of the generated crystal, improving the quality of the single crystal optical fiber 5, and also improving the stability of the crystallization process.

[0077] In an optional embodiment, in S1, the first laser 11 emits a first laser beam 111 focused on the raw material rod 3 of the optical fiber preparation device, including:

[0078] S11, shaping the first laser beam 111 into a ring laser through the first shaping lens 121;

[0079] S12, changing the beam path of the first laser beam 111 through the third reflecting mirror 122;

[0080] S13, focusing the first laser beam 111 on the top of the raw material rod 3 through the annular parabolic mirror 123.

[0081] In the process of preparing optical fiber, the first laser beam 111 emitted from the first laser 11 has a beam path extending along the second direction Y, and after passing through the first shaping lens 121, it will be shaped into a ring laser; then after being reflected by the third reflector 122, the beam path becomes to extend upward along the first direction X; finally, after entering the annular parabolic mirror 123, it is focused on the top of the raw material rod 3, thereby heating the raw material rod 3. It can be seen that the optical fiber preparation method enables the first laser beam 111 to have a high degree of adjustment freedom, and is independent of and does not interfere with the second laser beam 211, thereby ensuring the convenience and accuracy of the operator during use.

[0082] In an optional embodiment, in S2, emitting a second laser beam 211 focused on the single crystal optical fiber 5 by the second laser 21 includes:

[0083] S21 , shaping the second laser beam 211 into a ring-shaped laser beam through the lens group 221 and focusing the laser beam on the single crystal optical fiber 5 .

[0084] In the optical fiber preparation method, after the second laser beam 211 is emitted from the second laser 21, its beam path extends along the second direction Y. After the second laser beam 211 enters the lens group 221, it will be shaped into a ring laser. Subsequently, the ring-shaped second laser beam 211 will be focused on the surface of the cylindrical single crystal optical fiber 5, thereby performing a heating and heat preservation operation on the single crystal optical fiber 5. It can be seen that the setting of the lens group 221 in the present application enables the second laser beam 211 to be focused on the surface of the cylindrical single crystal optical fiber 5 in the form of a ring laser, so that it can be heated more evenly and comprehensively, and the ring laser can also better avoid laser leakage, further ensuring the safety of the optical fiber preparation device 100. At the same time, the setting of the independent lens group 221 also enables the focus point of the second laser beam 211 to be adjusted more freely, thereby improving the adjustment freedom of the optical fiber preparation device 100, and thus enabling the operator to adjust to the ideal temperature field more accurately and conveniently.

[0085] In an optional embodiment, in S21, the second laser beam 211 is shaped into a ring laser through the lens group 221 and focused on the single crystal optical fiber 5, including:

[0086] S211, shaping the second laser beam 211 into a ring laser through a second shaping lens 2211;

[0087] S212 , focusing the second laser beam 211 onto the single crystal optical fiber 5 through the hollow lens 2212 .

[0088] After the second laser beam 211 enters the lens group 221, it is shaped into a ring laser by the second shaping lens 2211. Subsequently, the ring-shaped second laser beam 211 enters the hollow lens 2212 and is focused by the hollow lens 2212 onto the surface of the cylindrical single crystal optical fiber 5, thereby performing a heating and heat preservation operation on the single crystal optical fiber 5. It can be seen that the optical fiber preparation method further improves the degree of freedom of adjustment in the optical fiber preparation process, thereby enabling the operator to more accurately and conveniently adjust to an ideal temperature field.

[0089] In an optional embodiment, in S21, the second laser beam 211 is shaped into a ring laser through the lens group 221 and focused on the single crystal optical fiber 5, and further includes:

[0090] S213 , reflecting the light emitted from the second shaping lens 2211 to the hollow lens 2212 through the reflecting mirror group 222 .

[0091] In the optical fiber preparation method, the second laser beam 211 emitted by the second laser 21 first extends along the second direction Y, and after entering the reflector group 222, its beam path changes to extend downward along the first direction X, and then enters the hollow lens 2212 for focusing. It can be seen that the setting of the reflector group 222 can better coordinate the second laser 21, the beam path of the second laser beam 211, the focus point position and the running direction of the single crystal optical fiber 5, so that during the optical fiber preparation process, the first laser beam 111 and the second laser beam 211 are independent of each other and do not interfere with each other, ensuring the independent control of the first laser beam 111 and the second laser beam 211, and improving the adjustment freedom of the optical system.

[0092] In an optional embodiment, in S2, emitting a second laser beam 211 focused on the single crystal optical fiber 5 by the second laser 21 includes:

[0093] S22 , adjusting the ring width of the second laser beam 211 through the beam expander group 223 .

[0094] In the optical fiber preparation method, the ring width of the second laser beam 211 after shaping is changed by adjusting the beam expansion ratio of the beam expansion mirror group 223. Specifically, the greater the beam expansion ratio of the beam expansion mirror group 223 to the second laser beam 211, the wider the ring width of the ring laser after subsequent shaping. It can be seen that the setting of the beam expansion mirror group 223 also effectively improves the adjustment freedom in the optical fiber preparation process, further facilitates the operator to adjust to the ideal temperature field, and improves the crystallization quality and stability in the preparation process.

[0095] In an optional embodiment, the optical fiber preparation method further includes:

[0096] S3. Drive the raw material rod 3 to move in a direction from the focal point of the first laser beam 111 to the focal point of the second laser beam 211 through the moving component 41.

[0097] In the optical fiber preparation method, the raw material rod 3 is driven by the moving part 41 to move upward along the first direction X, and the first laser beam 111 is focused on the top of the raw material rod 3 to melt and crystallize the raw material rod 3 into a single crystal optical fiber 5. With the continuous driving of the moving part 41, the newly generated single crystal optical fiber 5 will also move upward along the first direction X. At this time, the second laser beam 211 will be focused on the position of the newly generated single crystal optical fiber 5 to post-heat the single crystal optical fiber 5, thereby achieving the effect of heat preservation and reducing the temperature gradient. It can be seen that in the entire preparation process, the first laser beam 111 and the second laser beam 211 are independent of each other and do not interfere with each other. Under the premise of not affecting the power of the first laser beam 111, the parameters such as the intensity and focusing position of the second laser beam 211 can be arbitrarily adjusted, which effectively improves the flexibility, independence, convenience and adjustment freedom in the optical fiber preparation process, so that the operator can more accurately and conveniently adjust the optical fiber preparation device 100 to the ideal temperature field, further ensuring the quality of the prepared optical fiber and the stability during the preparation process.

[0098] It should be noted that the technical solutions or technical features described in the above embodiments can be combined or supplemented with each other without causing conflicts. The scope of protection of this application is not limited to the precise structures described in the above embodiments and shown in the drawings; all modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of this application should be included in the scope of protection of this application.

Claims

1. An optical system, applied to an optical fiber preparation device, characterized in that: include: A first heating system, the first heating system comprising a first laser and a first optical path component; The first laser is used to emit a first laser beam, and the first optical path component is used to focus the first laser beam on the raw material rod of the optical fiber preparation device; a second heating system, the second heating system comprising a second laser and a second optical path component; the second laser is used to emit a second laser beam, and the second optical path component is used to focus the second laser beam on a position of the raw material rod that has been heated by the first heating system; The second optical path component includes a lens group; the lens group is used to autonomously adjust the second laser beam to adjust the temperature field; The lens group includes a second shaping lens and a hollow lens; wherein the second shaping lens and the hollow lens are both located on the beam path of the second laser beam; the second shaping lens is used to shape the second laser beam into a ring laser; and the hollow lens is used to focus the second laser beam.

2. The optical system according to claim 1, wherein: The second shaping lens includes two aconical lenses, and the plane ends of the two aconical lenses are arranged opposite to each other; the conical end of one aconical lens is arranged in a direction pointing to the second laser, and the conical end of the other aconical lens is arranged in a direction away from the second laser.

3. The optical system according to claim 1, wherein: The second optical path component also includes a reflector group, which is arranged on the outgoing light beam path of the second shaping lens and is used to reflect the ring laser to the hollow lens.

4. The optical system according to claim 3, characterized in that The reflector group includes a first reflector and a second reflector; the hollow lens includes a first hollow lens and a second hollow lens; the second laser beam is a two-path beam; The first reflector is used to reflect one of the second laser beams to the first hollow lens; and the second reflector is used to reflect the other of the second laser beams to the second hollow lens.

5. The optical system according to claim 1, wherein: The second optical path component also includes a beam expander lens group, which is arranged on the beam path of the second laser beam and is used to adjust the ring width of the second laser beam.

6. The optical system according to claim 5, characterized in that The second laser beam is a two-path beam; the beam expander group is used to adjust the spacing distance between the two second laser beams.

7. The optical system according to claim 1, wherein: The first optical path component includes a first shaping lens, a third reflecting mirror and an annular parabolic mirror; the first shaping lens, the third reflecting mirror and the annular parabolic mirror are all arranged on the beam path of the first laser beam; Among them, the first shaping lens is used to shape the first laser beam into a ring laser; the third reflector is used to reflect the first laser beam emitted by the first shaping lens to the annular parabolic mirror; and the annular parabolic mirror is used to focus the first laser beam on the raw material rod.

8. An optical fiber preparation device, characterized in that: It comprises a mounting frame, a raw material bar and an optical system as claimed in any one of claims 1 to 7; Wherein, the optical system and the raw material rod are both mounted on the mounting frame; the mounting frame includes a moving component, and the moving component is connected to the raw material rod and is used to drive the raw material rod to move.

9. The optical fiber preparation device according to claim 8, characterized in that: In the height direction of the mounting frame, the second focusing point of the second laser beam is higher than the first focusing point of the first laser beam; and the moving component is used to drive the raw material rod to move in the direction from the first focusing point to the second focusing point.

10. The optical fiber preparation device according to claim 8, characterized in that: The mounting frame includes a panel and a column; the panel includes a first panel and a second panel, the first panel and the second panel are symmetrically arranged along the height direction of the mounting frame, and the first panel is higher than the second panel; both ends of the plurality of columns are respectively against the first panel and the second panel; the first heating system is arranged between the first panel and the second panel; the second heating system is arranged on a side of the first panel away from the second panel; The first panel includes a focusing hole, and the second panel includes an operation hole; the raw material rod is arranged through the operation hole; the first laser beam is focused on the top of the raw material rod, and the second laser beam passes through the focusing hole and is focused above the raw material rod.

11. A method for preparing an optical fiber, characterized in that: include: A first laser is used to emit a first laser beam focused on the raw material rod of the optical fiber preparation device, wherein the first laser beam is used to heat the raw material rod and form a single crystal optical fiber; Emits a second laser beam focused on the single crystal optical fiber through a second laser, wherein the second laser beam is used to heat the single crystal optical fiber; Wherein, the second laser beam emitted by the second laser and focused on the single crystal optical fiber comprises: The second laser beam is shaped into a ring laser through a lens group and focused on the single crystal optical fiber; The step of shaping the second laser beam into a ring laser through a lens group and focusing the second laser beam on the single crystal optical fiber comprises: shaping the second laser beam into a ring laser by a second shaping lens; The second laser beam is focused onto the single crystal optical fiber through a hollow lens.

12. The method for preparing an optical fiber according to claim 11, characterized in that: The first laser beam emitted by the first laser and focused on the raw material rod of the optical fiber preparation device comprises: shaping the first laser beam into a ring laser by a first shaping lens; changing the beam path of the first laser beam by a third reflecting mirror; The first laser beam is focused on the top of the raw material rod by an annular parabolic mirror.

13. The method for preparing an optical fiber according to claim 11, wherein: The step of shaping the second laser beam into a ring laser and focusing the second laser beam on the single crystal optical fiber through a lens group further comprises: The second shaping lens output from the second shaping lens is reflected to the hollow lens by a reflecting mirror group.

14. The method for preparing an optical fiber according to claim 11, wherein: The second laser beam emitted by the second laser and focused on the single crystal optical fiber comprises: The ring width of the second laser beam is adjusted by a beam expander lens group.

15. The method for preparing an optical fiber according to claim 11, characterized in that: The optical fiber preparation method further comprises: The raw material rod is driven by a moving component to move in a direction from a focal point of the first laser beam to a focal point of the second laser beam.

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