A microcrystalline glass composite optical fiber and a preparation method and application thereof

Abstract

The present application provides a kind of glass-ceramic composite optical fiber, the optical fiber includes cladding and core, the cladding is quartz glass, the core is luminescent ion doped silicate glass-ceramic, with high thermal stability and mechanical strength, can be realized with standard quartz optical fiber low-loss fusion;And by heat treatment in the core precipitates two crystal phases Li2Si2O5 and LiAlSi4O 10 , can provide two crystal field environments, respectively realize transition metal ion and rare earth ion doping, combined with the advantages of transition metal ion and rare earth ion luminescence, and then obtain new band luminescence, ultra-wideband luminescence and / or high gain luminescence, endow the optical fiber with high gain and ultra-wideband characteristics.In addition, the present application also provides the preparation method of the glass-ceramic composite optical fiber and its application in optical fiber amplifier and laser generating element.

Description

Technical Field

[0001] This invention belongs to the field of special optical fiber materials technology, specifically relating to a microcrystalline glass composite optical fiber and its preparation method, as well as the application of the composite optical fiber in laser generating elements and fiber amplifiers. Background Technology

[0002] With the rapid development of fields such as optical fiber communication, laser processing, medical diagnostics, and defense technology, increasingly higher requirements are being placed on the performance of gain optical fibers, which are the core materials. Traditional silica optical fibers dominate due to their excellent transmission performance, mechanical strength, and mature manufacturing processes. However, the inherent physicochemical properties of silica glass limit its further development: First, silica glass has high phonon energy, and when doped with rare-earth luminescent ions, the high nonradiative transition probability leads to a shortened upper level lifetime and reduced luminous efficiency, especially for mid-infrared emission, where the multiphonon relaxation effect is particularly severe; second, the solubility and ability to uniformly disperse rare-earth ions in silica glass are limited, and high-concentration doping easily induces concentration quenching, resulting in lower gain in silica optical fibers.

[0003] The core advantage of microcrystalline glass optical fiber stems from the composite structure of internal nanocrystals and glass matrix, which cleverly combines the excellent optical properties of crystals with the ease of processing glass. Compared with traditional silica optical fibers, it has the following advantages: 1) It can achieve high concentration doping and avoid concentration quenching. In glass-ceramic optical fibers, luminescent ions (rare earth luminescent ions and transition metal ions) can preferentially dissolve in specific crystal phases, achieving local high concentration but spatially ordered distribution. The luminescent ions have fixed positions in the crystal lattice, effectively reducing non-radiative energy transfer, thereby suppressing concentration quenching while maintaining high gain; 2) It has excellent thermal and chemical stability. Rare earth ions or transition metal ions are "locked" in the crystal lattice, making their diffusion and migration difficult. This means that the device performance is more stable, the lifetime is longer, and it is more resistant to "photodarkening" effect when operating with high-power lasers; 3) The crystal field environment can change the emission spectrum of rare earth ions, making it broader or generating new peak positions. By selecting different matrix microcrystals, the emission wavelength can be flexibly tuned, which is difficult to achieve with a single quartz matrix. Moreover, transition metal ions are greatly affected by the crystal field environment. Glass-ceramic fibers can provide them with a strong crystal field effect, enabling glass-ceramic optical fibers to effectively utilize the excellent luminescence performance of transition metal ions (such as broadband emission, new band emission, etc.).

[0004] However, existing light-emitting ion-doped glass-ceramic fibers have the following problems: 1) The softening temperature of glass-ceramic fibers differs greatly from that of silica fibers, making them unsuitable for low-loss fusion splicing with standard silica fibers; 2) Most glass-ceramic fibers precipitate only one crystal phase and provide only one crystal field environment, resulting in narrow applicability.

[0005] Therefore, there is an urgent need in this field for a new technical solution that can successfully integrate nanocrystals with high luminous efficiency and ultra-wideband luminous properties into optical fibers without sacrificing the good transmission performance and mechanical properties of optical fibers, thereby achieving high-gain ultra-wideband luminous properties. Summary of the Invention

[0006] To address the aforementioned technical problems, one aspect of the present invention provides a microcrystalline glass composite optical fiber, wherein the cladding is made of quartz glass and the fiber core is made of luminescent ion-doped silicate microcrystalline glass, exhibiting high thermal stability and mechanical strength, and enabling low-loss fusion splicing with standard quartz optical fibers; furthermore, two crystalline phases are precipitated in the fiber core, providing two crystal field environments, respectively enabling transition metal ion and rare earth ion doping, thus endowing the optical fiber with high gain and ultra-wideband characteristics. Another aspect of the present invention provides a method for fabricating the microcrystalline glass composite optical fiber and its application in fiber amplifiers and laser generating elements (such as fiber lasers).

[0007] The specific technical solution adopted by the present invention to solve its technical problem is as follows:

[0008] A microcrystalline glass composite optical fiber includes a cladding and a core. The cladding is made of quartz glass, and the core is made of luminescent ion-doped silicate microcrystalline glass. The composition of the core, expressed as a weight percentage, includes: SiO2: 68-75%; Li2O: 10-15%; ZrO2: 5-10%; Al2O3: 1-5%; P2O5: 1-5%; Na2O: 1-5%; Sb2O5: 0-1%; and luminescent ion oxide: 0.05-5.5%. Using quartz glass as the cladding allows for low-loss fusion splicing with standard quartz optical fibers. The silicate-based microcrystalline glass possesses high rare-earth ion solubility, excellent thermal stability, and chemical stability. The silicate nanocrystals precipitated in the core "lock" rare-earth ions and / or transition metal ions within the crystal lattice, making their diffusion and migration difficult. This enables high-power laser output, resulting in more stable device performance, longer lifespan, and better resistance to photodarkening effects.

[0009] Understandably, the cladding covers the surface of the fiber core.

[0010] Furthermore, the diameter of the microcrystalline glass composite optical fiber is 120~130 μm, the diameter of the fiber core is 5~15 μm, and the size of the nanocrystals in the fiber core is 10~50 nm.

[0011] Furthermore, the luminescent ion oxide is selected from rare earth ion oxides and transition metal ion oxides.

[0012] Furthermore, the optical fiber is a single-mode optical fiber with a numerical aperture of 0.1~0.2.

[0013] Furthermore, the silicate nanocrystals are luminescent ion-doped lithium disilicate (Li₂Si₂O₅, which has high strength and excellent chemical strengthenability) and spodumene (LiAlSi₄O₅). 10 It has an extremely low or even zero coefficient of thermal expansion. The fiber core can provide two crystal field environments, allowing for transition metal ion and rare earth ion doping respectively. This combines the luminescence advantages of transition metal ions and rare earth ions, thereby achieving new wavelength emission, ultra-wideband emission, and / or high-gain emission, endowing the optical fiber with high-gain and ultra-wideband characteristics. For example, by controlling the matrix glass composition, luminescent ion doping concentration, and heat treatment process parameters, Ni can be precipitated in the fiber core. 2+ Doping with Li2Si2O5 and Er 3+ Doped LiAlSi4O 10 Two types of silicate nanocrystals can achieve ultra-wideband emission covering 1100~1650 nm, and can then be applied to fiber amplifiers and tunable fiber lasers.

[0014] Furthermore, by controlling the matrix glass composition, luminescent ion doping concentration, and heat treatment process parameters, Ni was precipitated in the fiber core. 2+ Doping Li2Si2O5 and Tm 3+ Doped LiAlSi4O 10 Two types of silicate nanocrystals, through Ni 2+ Sensitized Tm 3+ This allows for the creation of more efficient and powerful ~1.8 µm band fiber lasers for medical, remote sensing, and OPO pump source applications.

[0015] Furthermore, by controlling the matrix glass composition, luminescent ion doping concentration, and heat treatment process parameters, Cr was precipitated in the fiber core. 2+ Doping with Li2Si2O5 and Yb 3+ Doped LiAlSi4O 10 Cr 2+ The emission band (~1000-1200 nm) and Yb 3+ The absorption peaks of Yb have significant overlap, resulting in very high energy transfer efficiency and ultimately strong emission at ~980 nm and ~1030 nm (from Yb). 3+ (Energy level transition).

[0016] Furthermore, the microcrystalline glass composite optical fiber also includes a polymer coating layer covering the cladding surface, which can provide the optical fiber with higher mechanical strength.

[0017] A method for preparing a microcrystalline glass composite optical fiber includes the following steps:

[0018] 1) Prepare fiber-core glass using the melt-annealing method according to the composition of the fiber core;

[0019] 2) The fiber core glass is processed into a round rod by mechanical cold working and assembled with a quartz glass tube to form a composite optical fiber preform.

[0020] 3) The initial optical fiber is drawn using the thermal drawing method;

[0021] 4) The initial optical fiber is heat-treated to obtain the microcrystalline glass composite optical fiber.

[0022] Furthermore, the conditions for preparing fiber core glass by melt-annealing include a melting temperature of 1550~1650 ℃.

[0023] Furthermore, the conditions for thermally drawing initial optical fibers include a drawing temperature of 1950~2100 ℃.

[0024] Furthermore, the heat treatment conditions include: a temperature of 750~800 ℃ and a time of 1~18 h.

[0025] Furthermore, the microcrystalline glass composite fiber is used in fiber amplifiers or laser generating elements. Laser generating elements include broadband tunable fiber lasers, single-frequency fiber lasers, and ultrafast fiber lasers.

[0026] Compared with the prior art, the technical advantages of the present invention are:

[0027] (1) The microcrystalline glass composite optical fiber of the present invention has a cladding of quartz glass and silicate nanocrystals precipitated in the fiber core. It has high thermal stability and mechanical strength and can be fused with standard quartz optical fiber with low loss.

[0028] (2) Lithium disilicate (Li2Si2O5) and spodumene (LiAlSi4O5) can be deposited in the core of the microcrystalline glass composite optical fiber of the present invention. 10 Two crystal phases provide two crystal field environments, which can realize transition metal ion and rare earth ion doping respectively. Combining the advantages of transition metal ion and rare earth ion luminescence, it endows optical fiber with high gain and ultra-wideband characteristics. Attached Figure Description

[0029] Figure 1 The image shows the XRD pattern of the microcrystalline glass composite optical fiber in Example 1.

[0030] Figure 2 This is a TEM image of the microcrystalline glass composite optical fiber in Example 1. Detailed Implementation

[0031] The following detailed description, in conjunction with specific embodiments, illustrates a microcrystalline glass composite optical fiber, its fabrication method, and its applications. This application can be implemented in many different forms and is not limited to the embodiments described herein. Rather, these embodiments are provided to provide a more thorough and complete understanding of the disclosure of this application.

[0032] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this application belongs. The terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting of the application.

[0033] As used herein, the terms “and / or,” “or / and,” and “and / or” may include any one of two or more of the related listed items, as well as any and all combinations of the related listed items, including any two related listed items, any more related listed items, or a combination of all the related listed items.

[0034] In this application, the technical features described in an open-ended manner include both closed technical solutions consisting of the listed features and open technical solutions that include the listed features.

[0035] In this application, numerical ranges are referred to as continuous unless otherwise specified, and include the minimum and maximum values ​​of the range, as well as every value between the minimum and maximum values. Furthermore, when the range refers to integers, it includes every integer between the minimum and maximum values ​​of the range. Additionally, when multiple ranges are provided to describe a feature or characteristic, the ranges may be merged. In other words, unless otherwise specified, all ranges disclosed herein should be understood to include any and all subranges to which they are incorporated.

[0036] Unless otherwise specified, the percentage content mentioned in this application refers to mass percentage for solid-liquid mixtures and solid-phase-solid mixtures, and volume percentage for liquid-phase-liquid mixtures.

[0037] Unless otherwise specified, all percentage concentrations mentioned in this application refer to the final concentration. The final concentration refers to the proportion of the added component in the system after the addition of that component.

[0038] Unless otherwise specified, the temperature parameters in this application may be either constant temperature processing or processing within a certain temperature range. The constant temperature processing allows for temperature fluctuations within the precision range controlled by the instrument.

[0039] In this application, room temperature generally refers to 4℃~30℃, and preferably 20±5℃.

[0040] A microcrystalline glass composite optical fiber, comprising a cladding and a core, wherein the cladding is quartz glass and the core is luminescent ion-doped silicate microcrystalline glass; the composition of the core, expressed as a weight percentage, contains: SiO2: 68~75%; Li2O: 10~15%; ZrO2: 5~10%; Al2O3: 1~5%; P2O5: 1~5%; Na2O: 1~5%; Sb2O5: 0~1%; luminescent ion oxide: 0.05~5.5%.

[0041] Specifically, the mass percentage of SiO2 includes, but is not limited to: 68%, 69%, 70%, 71.45%, 72%, 73%, 74%, 75%, or any range between the two mentioned above.

[0042] Specifically, the mass percentage of Li2O includes, but is not limited to: 10%, 11%, 12%, 13%, 14%, 15%, or any range between the two mentioned above.

[0043] Specifically, the mass percentage of ZrO2 includes, but is not limited to: 5%, 5.5%, 6%, 6.5%, 7%, 7.5%, 8%, 8.5%, 9%, 9.5%, 10%, or any range between the two mentioned above.

[0044] Specifically, the mass percentage of Al2O3 includes, but is not limited to, 1%, 2%, 3%, 4%, 5%, or any range between the two mentioned above.

[0045] Specifically, the mass percentage of P2O5 includes, but is not limited to, 1%, 2%, 3%, 4%, 5%, or any range between the two mentioned above.

[0046] Specifically, the mass percentage of Na2O includes, but is not limited to, 1%, 2%, 3%, 4%, 5%, or any range between the two mentioned above.

[0047] Specifically, the mass percentage of Sb2O5 includes, but is not limited to: 0%, 0.3%, 0.5%, 0.7%, 1%, or any range between the two mentioned above.

[0048] Specifically, the mass percentage of the luminescent ion oxide includes, but is not limited to: 0.05%, 0.1%, 0.3%, 0.55%, 1%, 1.5%, 2%, 2.5%, 3%, 3.5%, 4%, 4.5%, 5%, 5.5%, or any range between the two for the foregoing.

[0049] Furthermore, the diameter of the microcrystalline glass composite optical fiber is 120~130 μm, the diameter of the fiber core is 5~15 μm, and the size of the nanocrystals in the fiber core is 10~50 nm.

[0050] Furthermore, the fiber core contains luminescent ion-doped Li₂Si₂O₅ and LiAlSi₄O₅. 10 Nanocrystals.

[0051] Furthermore, the luminescent ion oxide is selected from rare earth ion oxides and transition metal ion oxides. Without limitation, the rare earth ion oxide can be one or more of Er₂O₃, Yb₂O₃, Tm₂O₃, Ho₂O₃, Nd₂O₃, Dy₂O₃, Tb₂O₃, and Ce₂O₃, and the transition metal ion oxide can be one or more of NiO, Cr₂O₃, Bi₂O₃, MnO, and FeO.

[0052] Furthermore, the optical fiber is a single-mode optical fiber with a numerical aperture of 0.1~0.2.

[0053] Furthermore, the microcrystalline glass composite optical fiber also includes a polymer coating layer covering the cladding surface, which can provide the optical fiber with higher mechanical strength.

[0054] A method for preparing a microcrystalline glass composite optical fiber includes the following steps:

[0055] 1) Prepare fiber-core glass using the melt-annealing method according to the composition of the fiber core;

[0056] 2) The fiber core glass is processed into a round rod by mechanical cold working and assembled with a quartz glass tube to form a composite optical fiber preform.

[0057] 3) The initial optical fiber is drawn using the thermal drawing method;

[0058] 4) The initial optical fiber is heat-treated to obtain the microcrystalline glass composite optical fiber.

[0059] Furthermore, the conditions for preparing fiber core glass by melt-annealing include a melting temperature of 1550~1650 ℃. Specifically, the melting temperature includes, but is not limited to, 1550 ℃, 1580 ℃, 1600 ℃, 1620 ℃, 1650 ℃, or any range between the two mentioned above.

[0060] Furthermore, the conditions for thermally drawing the initial optical fiber include a drawing temperature of 1950~2100 ℃. Specifically, the drawing temperature includes, but is not limited to: 1950 ℃, 1980 ℃, 2000 ℃, 2020 ℃, 2050 ℃, 2070 ℃, 2100 ℃, or any range between the two mentioned above.

[0061] Further, the heat treatment conditions include: a temperature of 750~800 °C and a time of 1~18 h. Specifically, the temperature includes, but is not limited to: 750 °C, 760 °C, 770 °C, 780 °C, 790 °C, 800 °C or any two of the foregoing; the time includes, but is not limited to: 1 h, 3 h, 6 h, 8 h, 10 h, 14 h, 16 h, 18 h or any two of the foregoing.

[0062] Furthermore, the microcrystalline glass composite fiber is used in fiber amplifiers or laser generating elements. Laser generating elements include broadband tunable fiber lasers, single-frequency fiber lasers, and ultrafast fiber lasers.

[0063] For experimental parameters not specified in the following specific embodiments, please refer to the guidelines given in this application document first, or refer to experimental manuals or other experimental methods known in the art, or refer to the experimental conditions recommended by the manufacturer.

[0064] The raw materials and reagents involved in the following specific embodiments can be obtained commercially or prepared by those skilled in the art using known methods.

[0065] Example 1

[0066] This embodiment is a microcrystalline glass composite optical fiber, which includes a cladding and a core. The cladding is quartz glass, and the core is a light-emitting ion-doped silicate microcrystalline glass. The composition of the core glass, expressed as a weight percentage, contains: SiO2: 71.45%; Li2O: 10%; ZrO2: 10%; Al2O3: 1%; P2O5: 2%; Na2O: 5%; Sb2O5: 0%; and light-emitting ion oxides NiO: 0.05% and Er2O3: 0.5%.

[0067] The optical fiber has a diameter of 125 μm, a core diameter of 10 μm, and nanocrystals in the core with a size of 25 nm. The optical fiber is a single-mode fiber with a numerical aperture of 0.15.

[0068] The above-mentioned method for preparing microcrystalline glass composite optical fibers includes the following steps:

[0069] 1) Large-sized fiber core glass was prepared by melt-annealing method: 600 g of glass raw material powder was weighed according to the formula, mixed evenly and poured into a platinum crucible for melting at a melting temperature of 1600 ℃.

[0070] 2) Large pieces of fiber core glass are processed into round rods using mechanical cold working methods, and then assembled with quartz glass tubes to form composite optical fiber preforms.

[0071] 3) The initial optical fiber was drawn on a commercial fiber drawing tower using the hot drawing method at a drawing temperature of 2050 ℃, and argon gas was used for protection during the drawing process;

[0072] 4) The initial optical fiber was heat-treated to obtain a microcrystalline glass composite optical fiber. The heat treatment temperature was 800 ℃ and the time was 6 h. Ni was precipitated in the fiber core. 2+ Doping with Li2Si2O5 and Er 3+ Doped LiAlSi4O 10 Two types of silicate nanocrystals, as shown in the attached image. Figure 1 The XRD pattern of the microcrystalline glass composite optical fiber is shown below. (Attached) Figure 2 The image shows a TEM image of a microcrystalline glass-in-fiber composite. The high-resolution transmission electron microscope image shows that the (102) interplanar spacing of Li2Si2O5 is 0.354 nm. The electron diffraction pattern is a polycrystalline diffraction ring.

[0073] Applications of the microcrystalline glass composite optical fiber in near-infrared 1100~1650 nm fiber amplifiers and tunable fiber lasers.

[0074] Example 2

[0075] This embodiment is a microcrystalline glass composite optical fiber, which includes a cladding and a core. The cladding is quartz glass, and the core is a light-emitting ion-doped silicate microcrystalline glass. The composition of the core glass, expressed as a weight percentage, contains: SiO2: 68%; Li2O: 15%; ZrO2: 5%; Al2O3: 1%; P2O5: 5%; Na2O: 3.5%; Sb2O5: 1%, and light-emitting ion oxides Cr2O3: 0.5% and Yb2O3: 1%.

[0076] The optical fiber has a diameter of 130 μm, a core diameter of 15 μm, and nanocrystals in the core with a size of 10 nm. The optical fiber is a single-mode fiber with a numerical aperture of 0.2.

[0077] The above-mentioned method for preparing microcrystalline glass composite optical fibers includes the following steps:

[0078] 1) Large-sized fiber core glass was prepared by melt-annealing method: 600 g of glass raw material powder was weighed according to the formula, mixed evenly and poured into a platinum crucible for melting. The melting temperature was 1550 ℃ and the melting process was carried out in a reducing atmosphere (a mixture of nitrogen and hydrogen in a volume ratio of 9:1).

[0079] 2) Large pieces of fiber core glass are processed into round rods using mechanical cold working methods, and then assembled with quartz glass tubes to form composite optical fiber preforms.

[0080] 3) The initial optical fiber was drawn on a commercial fiber drawing tower using the hot drawing method at a drawing temperature of 1950 ℃, and argon gas was used for protection during the drawing process;

[0081] 4) The initial optical fiber was heat-treated to obtain a microcrystalline glass composite optical fiber. The heat treatment temperature was 750 ℃ ​​and the time was 1 h. Nitrogen gas was used for protection during the heat treatment process, and Cr was precipitated in the fiber core. 2+ Doping with Li2Si2O5 and Yb 3+ Doped LiAlSi4O 10 Two types of silicate nanocrystals.

[0082] Applications of the microcrystalline glass composite optical fiber in ~980 nm and ~1030 nm fiber amplifiers and fiber lasers.

[0083] Example 3

[0084] This embodiment is a microcrystalline glass composite optical fiber, which includes a cladding and a core. The cladding is quartz glass, and the core is a light-emitting ion-doped silicate microcrystalline glass. The composition of the core glass, expressed as a weight percentage, contains: SiO2: 75%; Li2O: 10%; ZrO2: 5.5%; Al2O3: 5%; P2O5: 1%; Na2O: 1%; Sb2O5: 0.5%; and light-emitting ion oxides NiO: 0.5% and Tm2O3: 1.5%.

[0085] The optical fiber has a diameter of 120 μm and a core diameter of 5 μm, with nanocrystals in the core measuring approximately 50 nm. The optical fiber is a single-mode fiber with a numerical aperture of 0.1.

[0086] The above-mentioned method for preparing microcrystalline glass composite optical fibers includes the following steps:

[0087] 1) Large-sized fiber core glass was prepared by melt-annealing method: 600 g of glass raw material powder was weighed according to the formula, mixed evenly and poured into a platinum crucible for melting at a melting temperature of 1650 ℃.

[0088] 2) Large pieces of fiber core glass are processed into round rods using mechanical cold working methods, and then assembled with quartz glass tubes to form composite optical fiber preforms.

[0089] 3) The initial optical fiber was drawn on a commercial fiber drawing tower using the hot drawing method at a drawing temperature of 2100 ℃, and argon gas was used for protection during the drawing process;

[0090] 4) The initial optical fiber was heat-treated to obtain a microcrystalline glass composite optical fiber. The heat treatment temperature was 800 ℃ and the time was 18 h. Nitrogen gas was used for protection during the heat treatment process, and Ni was precipitated in the fiber core. 2+ Doping Li2Si2O5 and Tm 3+ Doped LiAlSi4O 10 Two types of silicate nanocrystals.

[0091] Applications of the microcrystalline glass composite optical fiber in near-infrared ~1.8 µm band fiber amplifiers and fiber lasers.

[0092] Example 4

[0093] This embodiment is a microcrystalline glass composite optical fiber, which includes a cladding and a core. The cladding is quartz glass, and the core is a light-emitting ion-doped silicate microcrystalline glass. The composition of the core glass, expressed as a weight percentage, contains: SiO2: 70%; Li2O: 12%; ZrO2: 8%; Al2O3: 2%; P2O5: 1%; Na2O: 1%; Sb2O5: 0.5%; light-emitting ion oxides NiO: 0.5% and Er2O3: 5%.

[0094] The optical fiber has a diameter of 125 μm, a core diameter of 10 μm, and a nanocrystal size of 20 nm in the core. The optical fiber is a single-mode optical fiber with a numerical aperture of 0.14.

[0095] The above-mentioned method for preparing microcrystalline glass composite optical fibers includes the following steps:

[0096] 1) Large-sized fiber core glass was prepared by melt-annealing method: 600 g of glass raw material powder was weighed according to the formula, mixed evenly and poured into a platinum crucible for melting at a melting temperature of 1580 ℃.

[0097] 2) Large pieces of fiber core glass are processed into round rods using mechanical cold working methods, and then assembled with quartz glass tubes to form composite optical fiber preforms.

[0098] 3) The initial optical fiber was drawn using the hot drawing method on a commercial fiber drawing tower at a drawing temperature of 1980 ℃, and argon gas was used for protection during the drawing process;

[0099] 4) The initial optical fiber was heat-treated to obtain a microcrystalline glass composite optical fiber. The heat treatment temperature was 780 ℃ and the time was 16 h. Nitrogen gas was used for protection during the heat treatment process, and Ni was precipitated in the fiber core. 2+ Doping with Li2Si2O5 and Er 3+ Doped LiAlSi4O 10 Two types of silicate nanocrystals.

[0100] Applications of the microcrystalline glass composite fiber in near-infrared ~1.5 μm band fiber amplifiers, narrow linewidth single-frequency fiber lasers, and high repetition rate ultrafast fiber lasers.

[0101] The technical features of the above embodiments can be combined in any way. For the sake of brevity, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0102] The embodiments described above are merely illustrative of several implementation methods of this application, intended to facilitate a detailed understanding of the technical solutions of this application, but should not be construed as limiting the scope of protection of the patent application. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of this application, and these all fall within the scope of protection of this application. It should be understood that technical solutions obtained by those skilled in the art based on the technical solutions provided in this application through logical analysis, reasoning, or limited experimentation are all within the scope of protection of the appended claims. Therefore, the scope of protection of this patent application should be determined by the content of the appended claims, and the specification can be used to interpret the content of the claims.

Claims

1. A microcrystalline glass composite optical fiber, characterized in that, The microcrystalline glass composite optical fiber comprises a cladding and a core. The cladding is quartz glass, and the core is luminescent ion-doped silicate microcrystalline glass. The composition of the core, expressed as a weight percentage, includes: SiO2: 68-75%; Li2O: 10-15%; ZrO2: 5-10%; Al2O3: 1-5%; P2O5: 1-5%; Na2O: 1-5%; Sb2O5: 0-1%; and luminescent ion oxide: 0.05-5.5%. The fiber core contains light-emitting ion-doped Li₂Si₂O₅ and LiAlSi₄O₅. 10 Nanocrystals.

2. The microcrystalline glass composite optical fiber according to claim 1, characterized in that, The luminescent ion oxide is selected from transition metal ion oxides and rare earth ion oxides.

3. The microcrystalline glass composite optical fiber according to claim 1, characterized in that, The diameter of the microcrystalline glass composite optical fiber is 120~130 μm, the diameter of the fiber core is 5~15 μm, and the size of the nanocrystals in the fiber core is 10~50 nm.

4. The microcrystalline glass composite optical fiber according to claim 1, characterized in that, The microcrystalline glass composite optical fiber is a single-mode optical fiber with a numerical aperture of 0.1~0.

2.

5. A microcrystalline glass composite optical fiber according to any one of claims 1 to 4, characterized in that, The microcrystalline glass composite optical fiber also includes a polymer coating layer covering the cladding surface.

6. The method for preparing the microcrystalline glass composite optical fiber according to any one of claims 1 to 5, characterized in that, Includes the following steps: 1) Prepare fiber-core glass using the melt-annealing method according to the composition of the fiber core; 2) The fiber core glass is processed into a round rod by mechanical cold working and assembled with a quartz glass tube to form a composite optical fiber preform. 3) The initial optical fiber is drawn using the thermal drawing method; 4) The initial optical fiber is heat-treated to obtain the microcrystalline glass composite optical fiber.

7. The method for preparing a microcrystalline glass composite optical fiber according to claim 6, characterized in that, The conditions for preparing fiber core glass by melt-annealing include a melting temperature of 1550~1650 ℃.

8. The method for preparing a microcrystalline glass composite optical fiber according to claim 6, characterized in that, The conditions for thermally drawn initial optical fibers include a drawing temperature of 1950~2100 ℃.

9. The method for preparing a microcrystalline glass composite optical fiber according to claim 6, characterized in that, The heat treatment conditions include: a temperature of 750~800 ℃ and a time of 1~18 h.

10. The application of the microcrystalline glass composite optical fiber according to any one of claims 1 to 5 in an optical fiber amplifier or a laser generating element.

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