Fiber grating assembly and fiber laser
By scattering cladding light by providing corrosion zones on the first cladding surface of the optical fiber, the heat accumulation problem caused by imperfect refractive index distribution in the fiber grating assembly is solved, extending the service life of the equipment and reducing production costs.
Patent Information
- Application Number
- CN202420309015.5
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2024-02-20
- Publication Date
- 2025-01-14
- Estimated Expiration
- 2034-02-20
AI Technical Summary
Due to process limitations, the existing fiber grating components lead to imperfect refractive index distribution, signal light is transmitted outside the fiber core, and cladding light enters the second cladding layer and coating layer, causing heat to the coating material, which in turn causes the fiber grating component to fail.
A corrosion zone is provided on the surface of the first cladding of the optical fiber to scatter cladding light, preventing light from being transmitted in the first cladding and avoiding heat accumulation. The fiber grating assembly includes a core and a first cladding wrapped around the outer wall of the core. It has a grating writing area along the axis of the core, and forms a refractive index distribution of the period by ultraviolet laser or femtosecond laser, combining multiple types of light and multiple lights. Corrosion zones are designed to scatter cladding light.
Effectively prevent heat accumulation caused by cladding light reflection, extend the service life of fiber lasers, reduce production costs, and improve the reliability of fiber grating components.
Smart Images
Figure CN222354089U_ABST
Abstract
Description
Technical Field
[0001] The utility model relates to the technical field of optical fibers, in particular to an optical fiber grating component and an optical fiber laser. Background Art
[0002] Optical fiber is an important device in fiber lasers. Ultraviolet laser or femtosecond laser is used to form a periodic refractive index distribution on the optical fiber, which can further reflect light of a specific wavelength.
[0003] Due to process limitations, this periodic refractive index distribution cannot be perfect. Therefore, in actual situations, the reflection of the fiber grating will cause the signal light to be transmitted outside the core, causing the cladding light to even enter the second cladding and coating layer. This situation generally causes the coating material to heat up, and this heat sometimes causes the fiber grating component to fail directly.
[0004] Therefore, there is an urgent need to provide a fiber grating component and a fiber laser to solve the above problems. Utility Model Content
[0005] The utility model aims to provide a fiber grating component and a fiber laser, which can prevent light from being transmitted in the first cladding layer and avoid heat accumulation caused by reflection of cladding light in the cladding layer.
[0006] In order to achieve the above objectives, the following technical solutions are provided:
[0007] A fiber grating assembly includes an optical fiber, wherein the optical fiber includes:
[0008] A fiber core, wherein a grating writing area is provided on the fiber core along the axial direction thereof, and the grating writing area is provided with a fiber grating;
[0009] A first cladding is annularly wrapped around the outer wall of the core, and a corrosion zone is provided on the outer surface of the first cladding, and the corrosion zone is used for scattering cladding light.
[0010] As an optional solution for the fiber grating assembly, the corrosion zone includes a first annular corrosion zone, which is arranged on the first cladding, overlaps with the grating writing zone, and the length of the first annular corrosion zone is not less than the length of the grating writing zone.
[0011] As an optional solution for the fiber grating assembly, the corrosion zone includes a second annular corrosion zone, which is arranged in the first cladding, and the second annular corrosion zone at least partially overlaps with the grating writing zone and extends along one end of the grating writing zone.
[0012] As an optional solution for the fiber grating component, the corrosion zone includes a third annular corrosion zone, at least two of the third annular corrosion zones are provided on the first cladding, two adjacent third annular corrosion zones are spaced apart on the first cladding, and two adjacent third annular corrosion zones are respectively located at opposite ends of the grating writing zone.
[0013] As an optional solution of the fiber grating assembly, the optical fiber further includes a second cladding, and the outer wall surface of the first cladding in the non-windowing area is provided with the second cladding.
[0014] As an optional solution of the fiber grating assembly, the optical fiber further includes a coating layer, and the outer wall surface of the second cladding is provided with the coating layer.
[0015] As an optional solution of the fiber grating assembly, the fiber grating assembly further includes a packaging shell, which is arranged on the optical fiber and is used to protect the grating writing area.
[0016] As an optional solution for the fiber grating assembly, the packaging shell includes a bottom shell and a cover plate, the bottom shell is recessed with a receiving groove, and limiting grooves are provided at opposite ends of the receiving groove. The light is embedded in the corresponding limiting grooves, and the cover plate is sealed and connected to the bottom shell.
[0017] As an optional solution of the fiber grating component, the first cladding includes a silica cladding, and the second cladding includes a polymer cladding.
[0018] A fiber laser, comprising the fiber grating assembly as described in any one of the above items.
[0019] Compared with the prior art, the utility model has the following beneficial effects:
[0020] The fiber grating assembly provided by the utility model comprises a fiber core and a first cladding annularly wrapped on the outer wall of the fiber core, wherein a grating writing area is provided on the fiber core along the axial direction of the fiber core, and a fiber grating with a periodic refractive index distribution can be written on the fiber core by ultraviolet laser or femtosecond laser in the grating writing area, so that a specific wavelength can be reflected to meet the needs of signal light transmission along the fiber core. By providing a corrosion area for scattering cladding light on the surface of the first cladding, it is convenient to scatter and dissipate the cladding light into space, prevent light from being transmitted in the first cladding, and avoid the cladding light from reflecting in the cladding to cause heat accumulation, thereby causing damage to the optical fiber.
[0021] The optical fiber laser provided by the utility model provides a corrosion area for scattering cladding light on the surface of the first cladding, so as to facilitate scattering and dissipating the cladding light into space, prevent light from being transmitted in the cladding, avoid cladding light from being reflected in the first cladding to cause heat accumulation, thereby causing damage to the optical fiber, and can extend the service life of the equipment and reduce R&D and production costs. BRIEF DESCRIPTION OF THE DRAWINGS
[0022] In order to more clearly illustrate the technical solutions in the embodiments of the present invention, the following briefly introduces the drawings required for use in the description of the embodiments of the present invention. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on the contents of the embodiments of the present invention and these drawings without paying any creative work.
[0023] Figure 1 It is a schematic diagram of the assembly of the fiber Bragg grating assembly in the embodiment of the utility model;
[0024] Figure 2 This is an exploded schematic diagram of a fiber Bragg grating assembly in an embodiment of the utility model;
[0025] Figure 3 This is a schematic diagram of the distribution of the first annular corrosion zone in the embodiment of the utility model;
[0026] Figure 4 This is a schematic diagram of the distribution of the second annular corrosion zone in the embodiment of the utility model;
[0027] Figure 5 This is a schematic diagram of the distribution of the third annular corrosion zone in the embodiment of the utility model;
[0028] Figure 6 It is a schematic diagram of the structure of the bottom shell in the embodiment of the utility model.
[0029] Reference numerals:
[0030] 100, optical fiber; 200, packaging shell; 201, bottom shell; 2011, receiving groove; 2012, limiting groove; 202, cover plate;
[0031] 101, fiber core; 102, first cladding; 103, second cladding;
[0032] 1011, grating writing area;
[0033] 1021, first annular corrosion zone; 1022, second annular corrosion zone; 1023, third annular corrosion zone. DETAILED DESCRIPTION
[0034] In order to make the purpose, technical scheme and advantages of the embodiments of the utility model clearer, the technical scheme in the embodiments of the utility model will be clearly and completely described below in conjunction with the drawings in the embodiments of the utility model. Obviously, the described embodiments are part of the embodiments of the utility model, not all of the embodiments. Generally, the components of the embodiments of the utility model described and shown in the drawings here can be arranged and designed in various different configurations.
[0035] In the description of the present utility model, it should be noted that the terms "upper", "lower", "left", "right", "vertical", "horizontal", "inside", "outside", etc. indicate the orientation or position relationship based on the orientation or position relationship shown in the accompanying drawings, or the orientation or position relationship in which the utility model product is usually placed when in use. They are only for the convenience of describing the present utility model and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation on the present utility model. In addition, the terms "first", "second", "third", etc. are only used to distinguish the description, and cannot be understood as indicating or implying relative importance. In the description of the present utility model, unless otherwise specified, "multiple" means two or more.
[0036] In the description of the present invention, it is also necessary to explain that, unless otherwise clearly specified and limited, the terms "set" and "connection" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.
[0037] The embodiments of the present invention are described in detail below, and examples of the embodiments are shown in the accompanying drawings, wherein the same or similar reference numerals throughout represent the same or similar elements or elements having the same or similar functions. The embodiments described below with reference to the accompanying drawings are exemplary and are only used to explain the present invention, and cannot be understood as limiting the present invention.
[0038] Fiber Bragg gratings are generally written on the core of an optical fiber using an ultraviolet laser or a femtosecond laser, so that the laser passing through the section of optical fiber forms a periodic refractive index distribution, thereby further being able to reflect light of a specific wavelength.
[0039] Due to process limitations, this periodic refractive index distribution cannot be perfect, so in actual situations, the reflection of the fiber grating will cause the signal light to be transmitted outside the core, and even enter the second cladding and coating layer. This situation generally causes the coating material to heat up, and in some advanced receiving bands of organic materials, such as the two-micron band, this heating is catastrophic and will directly cause the fiber grating to fail.
[0040] How to solve the heating problem under the existing process level and thus improve the reliability of the grating is an urgent problem to be solved for special wavelength fiber Bragg grating components.
[0041] In order to avoid the cladding light from reflecting in the cladding and causing heat accumulation, this embodiment provides a fiber Bragg grating component and a fiber laser. Figures 1 to 6 The specific contents of this embodiment are described in detail.
[0042] like Figures 1 to 3 As shown, the fiber grating assembly includes an optical fiber 100 and a packaging shell 200. The optical fiber 100 includes a core 101 and a first cladding 102. A grating writing area 1011 is provided on the core 101 along its axial direction, and a fiber grating is etched in the grating writing area 1011. The first cladding 102 is annularly wrapped around the outer wall of the core 101, and a corrosion area is provided on the outer surface of the first cladding 102, which is used to scatter the cladding light and prevent the light from transmitting in the first cladding 102.
[0043] In short, the fiber grating assembly provided by the utility model includes a core 101 and a first cladding 102 annularly wrapped on the outer wall of the core 101, wherein a grating writing area 1011 is provided on the core 101 along the axial direction of the core 101, and a fiber grating with a periodic refractive index distribution can be formed on the core 101 by ultraviolet laser or femtosecond laser in the grating writing area 1011, so that a specific wavelength can be reflected to meet the needs of signal light transmission along the core 101. By providing a corrosion area for scattering cladding light on the surface of the first cladding 102, it is convenient to scatter and dissipate the cladding light into space, prevent light from being transmitted in the first cladding 102, and avoid the cladding light from reflecting in the cladding to cause heat accumulation.
[0044] Optionally, a chemical substance is used to etch the etched area of the first cladding 102, so that a plurality of pits are formed on the surface of the first cladding 102 to scatter the cladding light. It can be understood that the size, shape, depth and number of the pits are limited according to actual use requirements, and no excessive restrictions are made here. It should be noted that the cladding light mentioned in this embodiment refers to the signal light transmitted in the non-core 101.
[0045] In the embodiment of the utility model, a combination of multiple corrosion zone solutions can be set for different application scenarios. In the embodiment of the utility model, the corrosion zone can include any one of the first annular corrosion zone 1021, the second annular corrosion zone 1022 or the third annular corrosion zone 1023.
[0046] For example, Figure 3As shown, in some application scenarios, a first annular corrosion area 1021 is provided on the first cladding 102, the first annular corrosion area 1021 overlaps with the grating writing area 1011, and the length of the first annular corrosion area 1021 is not less than the length of the grating writing area 1011. The first annular corrosion area 1021 can directly process the light scattered by the grating part, and can dissipate more energy by lengthening the corrosion area and increasing the package. The grating light component of this embodiment can be applied to a low-reflection grating, and is used to combine a cladding light stripper and a low-reflection grating into one, which can reduce the fusion points in the system and reduce the total optical path length of the system, improve the laser transmission efficiency, and reduce the loss.
[0047] For example, Figure 4 As shown, in other application scenarios, a second annular etched area 1022 is provided on the first cladding 102, and the second annular etched area 1022 at least partially overlaps with the grating writing area 1011 and extends along one end of the grating writing area 1011. The second annular etched area 1022 can be used to handle the light path situation where cladding light is injected from the extension direction. This avoids the situation where the grating writing area 1011 is too complicated in function, and the grating area is used to handle the leakage caused by the grating, and the cladding light of the active area is also handled, resulting in excessive load.
[0048] For example, Figure 5 As shown, in other application scenarios, at least two third annular corrosion areas 1023 are provided on the first cladding 102, and two adjacent third annular corrosion areas 1023 are arranged at intervals on the first cladding 102, and the two adjacent third annular corrosion areas 1023 are respectively located at opposite ends of the grating writing area 1011. Since the corrosion areas are arranged on both sides of the grating writing area 1011. In some writing, the grating itself is damaged, and etching in the grating area will lead to a decrease in the yield rate. In this embodiment, the corrosion areas can be arranged on both sides of the writing area, and the cladding light can be dissipated into space, and the technical effect of preventing a large amount of heat from accumulating in the first cladding 102 can be achieved.
[0049] Furthermore, if Figures 3 to 5 As shown, the optical fiber 100 also includes a second cladding 103 and a coating layer, and the outer wall surface of the first cladding 102 in the non-windowing area is provided with the second cladding 103. The outer wall surface of the second cladding 103 is provided with a coating layer. The coating layer is made of polyimide material. The first cladding 102 includes a quartz cladding, and the second cladding 103 includes a polymer cladding. The non-windowing area referred to in this embodiment refers to an area on the optical fiber that has not been damaged and has two complete claddings and a coating layer.
[0050] Furthermore, if Figure 1 , Figure 2 and 6As shown, the packaging shell 200 of the fiber grating assembly is sleeved on the optical fiber 100 and used to protect the grating writing area 1011. The fiber grating is packaged in the shell, which effectively collects and absorbs the cladding light scattered in the space and prevents the cladding light from overflowing.
[0051] For example, Figure 2 As shown, the packaging shell 200 includes a bottom shell 201 and a cover plate 202. The bottom shell 201 is concavely provided with a receiving groove 2011. The two opposite ends of the receiving groove 2011 are provided with limiting grooves 2012. The second cladding 103 of the optical fiber 100 is embedded in the corresponding limiting grooves 2012. The cover plate 202 is sealed and connected to the bottom shell 201. Optionally, the cover plate 202 and the bottom shell 201 can be fixed by, but not limited to, gluing.
[0052] This embodiment also provides a fiber laser, which includes the fiber grating assembly mentioned above. By providing a corrosion area for scattering cladding light on the surface of the first cladding 102, the cladding light is scattered and dissipated into space, preventing light from transmitting in the cladding, and avoiding heat accumulation caused by the cladding light reflecting in the first cladding 102.
[0053] Note that the above are only preferred embodiments of the present invention and the technical principles used. Those skilled in the art will understand that the present invention is not limited to the specific embodiments described here, and that various obvious changes, readjustments and substitutions can be made by those skilled in the art without departing from the scope of protection of the present invention. Therefore, although the present invention is described in more detail through the above embodiments, the present invention is not limited to the above embodiments, and may include more other equivalent embodiments without departing from the concept of the present invention, and the scope of the present invention is determined by the scope of the appended claims.
Claims
1. A fiber Bragg grating assembly, characterized in that: The invention comprises an optical fiber (100), wherein the optical fiber (100) comprises: A fiber core (101), wherein a grating writing area (1011) is provided on the fiber core (101) along its axial direction, and the grating writing area (1011) is provided with a fiber grating; A first cladding (102), wherein the first cladding (102) is annularly wrapped around the outer wall surface of the core (101), and a corrosion zone is provided on the outer surface of the first cladding (102), and the corrosion zone is used to scatter cladding light; The corrosion zone comprises a second annular corrosion zone (1022) or a third annular corrosion zone (1023), wherein the second annular corrosion zone (1022) is arranged on the first cladding (102), and the second annular corrosion zone (1022) at least partially overlaps with the grating writing zone (1011) and extends along one end of the grating writing zone (1011); at least two third annular corrosion zones (1023) are arranged on the first cladding (102), and two adjacent third annular corrosion zones (1023) are arranged on the first cladding (102) at intervals, and the two adjacent third annular corrosion zones (1023) are respectively located at two ends of the grating writing zone (1011).
2. The fiber Bragg grating assembly according to claim 1, characterized in that: The optical fiber (100) further comprises a second cladding (103), and the second cladding (103) is provided on the outer wall surface of the first cladding (102) in the non-windowed area.
3. The fiber Bragg grating assembly according to claim 2, characterized in that: The optical fiber (100) further comprises a coating layer, and the outer wall surface of the second cladding (103) is provided with the coating layer.
4. The fiber Bragg grating assembly according to claim 3, characterized in that: The fiber grating assembly also includes a packaging shell (200), which is arranged on the optical fiber (100) and is used to protect the grating writing area (1011).
5. The fiber Bragg grating assembly according to claim 4, characterized in that: The packaging shell (200) comprises a bottom shell (201) and a cover plate (202); the bottom shell (201) is provided with a recessed receiving groove (2011); both ends of the receiving groove (2011) are provided with limiting grooves (2012); the optical fiber (100) is embedded in the corresponding limiting groove (2012); and the cover plate (202) is sealedly connected to the bottom shell (201).
6. The fiber Bragg grating assembly according to claim 2, characterized in that: The first cladding (102) comprises a quartz cladding, and the second cladding (103) comprises a polymer cladding.
7. A fiber laser, characterized in that: The fiber laser comprises the fiber Bragg grating assembly according to any one of claims 1-6.