A radiation-resistant erbium-doped optical fiber and its preparation method and application

Abstract

The present invention provides radiation-resistant erbium-doped optical fiber and its preparation method and application. The method comprises: depositing a loose layer on the inner wall of a quartz reaction tube; immersing the quartz reaction tube in a liquid containing Er 3+ , Ga 3+ ,La 3+ , Al 3+ The doping solution is dried in a dry atmosphere to obtain a first doped quartz tube. 3+ The concentration of the erbium-doped optical fiber is 0.2-500 g / L; a Ge2O3 layer is deposited on the loose layer of the first doped quartz tube to obtain a second doped quartz tube; the second doped quartz tube is sintered into a quartz preform rod and then inserted into a quartz sleeve, and then drawn into a radiation-resistant erbium-doped optical fiber in a drawing tower; the preparation method of the radiation-resistant erbium-doped optical fiber provided by the present invention is through Ga 3+ The doping can reduce the noise coefficient of the radiation-resistant erbium-doped fiber, while reducing the background loss, further improving the comprehensive performance of the radiation-resistant erbium-doped fiber.

Description

Technical Field

[0001] The present invention relates to the field of optical fiber technology, and in particular to a radiation-resistant erbium-doped optical fiber and a preparation method and application thereof. Background Art

[0002] Optical fiber has the advantages of high transmission efficiency, low loss, light weight and anti-static interference, and has been widely used in the field of communications. Rare earth (such as Yb, Er, Tm) doped quartz fiber lasers or amplifiers have the advantages of light weight, small size, high electro-optical conversion efficiency, high peak power, narrow line width, etc., and have important application value in space communications, lidar, space debris disposal, airborne laser weapons, etc. However, when performing space missions, lasers or amplifiers will face harsh particle radiation (such as protons, electrons, X-rays and gamma rays). Particle radiation will cause the loss of active optical fibers in lasers or amplifiers to increase sharply, the laser slope efficiency to drop significantly, and in severe cases there will even be no laser output.

[0003] In order to improve the radiation resistance of optical fiber, researchers at home and abroad have done a lot of research work and proposed corresponding solutions. At present, the optical fiber radiation resistance technology mainly improves the radiation resistance of optical fiber through optical fiber component design, optical fiber carrier gas, thermal bleaching and photobleaching technology. In erbium-doped radiation-resistant optical fiber, it is mainly based on component design to improve the radiation resistance of optical fiber by increasing the proportion of Ge element. The Ge element is relatively stable in the air and is not easy to react chemically. This stability allows Ge to maintain its original physical and chemical properties when irradiated, and it is not easy to produce obvious performance changes. The electronic structure of the Ge element enables it to effectively absorb and disperse radiation energy, thereby reducing damage to the optical fiber material. This characteristic helps to maintain the stability and reliability of the optical fiber and ensure that the optical signal is not disturbed during transmission.

[0004] Since the refractive index of Ge is higher than that of silica, excessive doping with Ge will lead to uneven refractive index distribution of the optical fiber, which may change the transmission mode and dispersion characteristics of the optical fiber. Changes in dispersion may cause distortion and increased loss of optical signals during transmission. Excessive doping with Ge may also introduce additional absorption and scattering losses, resulting in increased attenuation of optical signals during transmission in the optical fiber, a larger noise coefficient, and affecting the transmission distance and signal quality of the optical fiber. Therefore, the existing Ge-containing radiation-resistant erbium-doped optical fiber has a large noise coefficient and large background loss to the optical fiber, making it difficult to meet the requirements for optical fiber in a high radiation environment. Summary of the invention

[0005] The purpose of the present invention is to provide a radiation-resistant erbium-doped optical fiber and a preparation method and application thereof, so as to improve the technical problems of the radiation-resistant erbium-doped optical fiber in the prior art, namely, large noise coefficient and large background loss of the optical fiber.

[0006] In order to solve the above technical problems, the present invention provides a method for preparing a radiation-resistant erbium-doped optical fiber, comprising the following steps:

[0007] S10, depositing a loose layer on the inner wall of the quartz reaction tube;

[0008] S20, immerse the quartz reaction tube in a solution containing Er 3+ , Ga 3+ ,La 3+ , Al 3+ The doping solution is dried in a dry atmosphere to obtain a first doped quartz tube. 3+ The preparation concentration is 0.2~500g / L;

[0009] S30, depositing a Ge2O3 layer on the loose layer of the first doped quartz tube to obtain a second doped quartz tube;

[0010] S40, shrinking the second doped quartz tube into a quartz preform rod, inserting the preform rod into a quartz sleeve, and drawing the preform rod into a radiation-resistant erbium-doped optical fiber in a drawing tower.

[0011] Preferably, step S10 specifically includes: the oxyhydrogen lamp moves from left to right, and SiCl4 and O2 are simultaneously introduced into the quartz reaction tube at 1300-1600° C., so as to obtain a quartz reaction tube with a loose layer.

[0012] Preferably, in step S20, the immersion time is 2 to 10 hours, the immersion temperature is 20 to 60° C., and during the immersion process, the quartz reaction tube is kept rotating at a speed of 10 r / min to 50 r / min.

[0013] Preferably, in step S20, in the doping solution: Er 3+ The preparation concentration is 0.5~2g / L, La 3+ The preparation concentration is 0.2~50g / L, Al 3+ The preparation concentration is 0.2~500g / L.

[0014] Preferably, before performing step S30, the method further includes: baking the first doped quartz tube in a chlorine atmosphere.

[0015] Preferably, step S30 specifically includes: the oxyhydrogen lamp moves from right to left, and GeCl4 and O2 are introduced into the first doped quartz tube at 1300-1700° C. to obtain a second doped quartz tube.

[0016] Preferably, in step S40, the temperature for shrinking the second doped quartz tube is 1900-2300° C., and the pressure inside the second doped quartz tube during shrinking is 0.1-0.3 Torr.

[0017] Correspondingly, the present invention also provides a radiation-resistant erbium-doped optical fiber, which is prepared by any of the above methods for preparing the radiation-resistant erbium-doped optical fiber.

[0018] Correspondingly, the present invention further provides an application of the radiation-resistant erbium-doped optical fiber as described above under the condition that the irradiation dose is greater than or equal to 1000 GY.

[0019] The beneficial effects of the present invention are as follows: Different from the prior art, the present invention provides a radiation-resistant erbium-doped optical fiber and a preparation method and application thereof, the method comprising: depositing a loose layer on the inner wall of a quartz reaction tube; immersing the quartz reaction tube in a liquid containing Er; 3+ , Ga 3+ ,La 3+ , Al 3+ The doping solution is dried in a dry atmosphere to obtain a first doped quartz tube. 3+ The concentration of the erbium-doped optical fiber is 0.2-500 g / L; a Ge2O3 layer is deposited on the loose layer of the first doped quartz tube to obtain a second doped quartz tube; the second doped quartz tube is sintered into a quartz preform rod and then inserted into a quartz sleeve, and then drawn into a radiation-resistant erbium-doped optical fiber in a drawing tower; the preparation method of the radiation-resistant erbium-doped optical fiber provided by the present invention comprises the following steps: 3+ , Ga 3+ ,La 3+ and Al 3+ :Er 3+ As a gain medium, it can absorb the pump light energy and convert it into the amplification of the signal light; La 3+ As Er 3+ The dispersant can enhance the radiation resistance of optical fiber, and La 3+ Doping has no negative impact on the gain performance of the optical fiber. 3+ Can adjust Er 3+ The degree of energy level broadening is manifested in the increase of the gain of longer wavelengths in the gain spectrum, and the gain of short wavelengths does not decrease much. 3+ The doping can reduce the noise coefficient of the radiation-resistant erbium-doped fiber, while reducing the background loss, further improving the comprehensive performance of the radiation-resistant erbium-doped fiber. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] Figure 1 A flow chart of a method for preparing a radiation-resistant erbium-doped optical fiber provided in an embodiment of the present invention;

[0021] Figure 2 The laser spectra of the embodiments and comparative examples of the present invention in the C band after irradiation are shown;

[0022] Figure 3This is a background loss diagram at 1200nm of Example 2 of the present invention after irradiation;

[0023] Figure 4 The noise index diagrams at the C-band of the embodiments and comparative examples of the present invention after irradiation are shown in FIG. DETAILED DESCRIPTION

[0024] The following will be combined with the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0025] As used in this article, "MCVD" refers to "modified chemical vapor deposition", which is a process in which the raw materials to be reacted are carried into the substrate tube from the air inlet end of the substrate tube using oxygen as a carrier gas, and the outside of the substrate tube is heated by a burner to indirectly heat the reaction raw materials in the substrate tube to produce a glass body, which is deposited on the inner wall of the substrate tube.

[0026] As used herein, "quartz reaction tube" refers to the high purity quartz reaction tube Heraeus F300.

[0027] See also Figure 1 , Figure 1 A flow chart of a method for preparing a radiation-resistant erbium-doped optical fiber provided in an embodiment of the present invention; the method for preparing the radiation-resistant erbium-doped optical fiber comprises the following steps:

[0028] S10, depositing a loose layer on the inner wall of the quartz reaction tube.

[0029] Specifically, step S10 also includes:

[0030] Using the MCVD process, a loose layer of SiO2 material is deposited on the inner wall of the quartz reaction tube to provide attachment points for the next step of liquid phase doping of rare earth ions.

[0031] Preferably, step S10 specifically includes: the oxyhydrogen lamp moves from left to right, and SiCl4 and O2 are simultaneously introduced into the quartz reaction tube at 1300-1600°C to obtain a quartz reaction tube with a loose layer; wherein, since the feed tube in the MCVD equipment is on the left side of the reaction tube, when the oxyhydrogen lamp moves from left to right, the oxyhydrogen lamp will heat the deposits on the inner wall of the tube again, thereby tightly fixing the loose layer inside the quartz reaction tube.

[0032] S20, immerse the quartz reaction tube in a solution containing Er 3+ , Ga 3+ ,La 3+ , Al 3+The doping solution is dried in a dry atmosphere to obtain a first doped quartz tube. 3+ The preparation concentration is 0.2~500g / L.

[0033] Specifically, step S20 also includes:

[0034] The quartz reaction tube was immersed in a solution containing Er 3+ , Ga 3+ ,La 3+ and Al 3+ In the doping solution, Er 3+ , Ga 3+ ,La 3+ and Al 3+ The doping solution is doped into the quartz reaction tube through the pores of the loose layer; wherein the solvent of the doping solution is deionized water or anhydrous ethanol, and the solute contains Er 3+ , Ga 3+ ,La 3+ and Al 3+ The quartz reaction tube is immersed in the doping solution for 2 to 10 hours at a temperature of 20 to 60°C. During the immersion process, the quartz reaction tube is rotated at a speed of 10 r / min to 50 r / min. The uniform rotation of the quartz reaction tube can make the solute adsorbed on the loose layer as evenly as possible.

[0035] In this embodiment, the doping solution contains: Er 3+ The preparation concentration is 0.5~2g / L, La 3+ The preparation concentration is 0.2~50g / L, Al 3+ The preparation concentration is 0.2~500g / L, Ga 3+ The concentration of Er is 0.2~500g / L. Since metal ions will significantly increase the background loss of optical fiber, metal ions should be introduced as little as possible during the general optical fiber preparation process. However, in order to improve the radiation resistance and gain performance of optical fiber, these ions must be introduced. Therefore, it is necessary to consider various factors comprehensively and limit Er 3+ , Ga 3+ ,La 3+ and Al 3+ The doping amount.

[0036] S30, depositing a Ge2O3 layer on the loose layer of the first doped quartz tube to obtain a second doped quartz tube.

[0037] Specifically, step S30 also includes:

[0038] S301, baking the first doped quartz tube in a chlorine atmosphere (at about 1200° C.) to remove moisture and hydroxyl groups in the first doped quartz tube;

[0039] S302, depositing a Ge2O3 layer on the loose layer of the first doped quartz tube by using an MCVD process to obtain a second doped quartz tube.

[0040] Specifically, step S302 includes: the oxyhydrogen lamp moves from right to left, and GeCl4 and O2 are simultaneously introduced into the first doped quartz tube at 1300-1700° C. to obtain a second doped quartz tube; wherein, when the oxyhydrogen lamp moves from right to left, the oxyhydrogen lamp will not heat the deposits on the inner wall of the reaction tube again, thereby greatly reducing the thermal volatilization of volatile substances (germanium oxide).

[0041] In this scheme, the purpose of depositing the Ge2O3 layer is twofold: one is to increase the refractive index of the fiber core, thereby determining the waveguide structure; the other is to improve the radiation resistance of the optical fiber.

[0042] S40, shrinking the second doped quartz tube into a quartz preform rod, inserting the preform rod into a quartz sleeve, and drawing the preform rod into a radiation-resistant erbium-doped optical fiber in a drawing tower.

[0043] Specifically, step S40 also includes:

[0044] S401, introducing oxygen into the second doped quartz tube and vitrifying the inner wall of the second doped quartz tube, and then sintering and shrinking the tube into a transparent quartz preform;

[0045] S402, inserting the quartz preform rod into a quartz sleeve, and drawing it into an optical fiber in a drawing tower, namely, a radiation-resistant erbium-doped optical fiber.

[0046] Preferably, in step S402, the temperature for shrinking the second doped quartz tube is 1900-2300° C., and the pressure inside the second doped quartz tube during shrinking is 0.1-0.3 Torr.

[0047] In the radiation-resistant erbium-doped optical fiber prepared in the embodiment of the present invention, Er 3+ As a gain medium, it can absorb the pump light energy and convert it into the amplification of the signal light; La 3+ As Er 3+ The dispersant can enhance the radiation resistance of optical fiber, and La 3+ Doping has no negative impact on the gain performance of the optical fiber; Al 3+ Can adjust Er 3+ The degree of energy level broadening is manifested in the increase of the gain of longer wavelengths in the gain spectrum, and the gain of short wavelengths does not drop much; 3+ The co-doping may promote the doping efficiency of erbium ions by changing the glass structure of silica-based optical fiber, thereby improving the flatness of the gain spectrum and increasing the doping ratio of erbium ions. Co-doping with gallium adjusts the optical fiber glass network structure and the interaction between gallium ions and erbium ions.

[0048] Specifically, the appropriate 3+ , Ga 3+ ,La 3+ and Al 3+ The doping level of Erbium-doped fiber can improve the gain performance of radiation-hardened Erbium-doped fiber and reduce the noise figure; however, too high doping level may lead to gain saturation and increased noise.

[0049] Correspondingly, the present invention also provides a radiation-resistant erbium-doped optical fiber, which is prepared by any of the above methods for preparing the radiation-resistant erbium-doped optical fiber.

[0050] Correspondingly, the present invention further provides an application of the radiation-resistant erbium-doped optical fiber as described above under the condition that the irradiation dose is greater than or equal to 1000 GY.

[0051] The technical solution of the present application is now described in conjunction with specific embodiments.

[0052] Embodiment 1:

[0053] Embodiment 1 of the present invention provides a method for preparing a radiation-resistant erbium-doped optical fiber, which comprises the following steps:

[0054] Step 1: deposit a loose layer of SiO2 on the inner wall of the quartz reaction tube. At this time, the temperature is 1500°C, the hydrogen and oxygen lamps move from left to right, and 300 Sccm of SiCl4 and 300 Sccm of O2 are introduced into the reaction tube;

[0055] Step 2: Immerse the quartz reaction tube with a loose layer of SiO2 in a solution containing Er. 3+ , Ga 3+ ,La 3+ and Al 3+ Immerse in an aqueous solution of ions for 2 to 10 hours and take it out. 3+ The preparation concentration is 0.5~0.6g / L, La 3+ The preparation concentration is 45~50g / L, Al 3+ The preparation concentration is 15~16g / L, Ga 3+ The concentration of the prepared solution is 2-5 g / L, wherein the quartz reaction tube keeps rotating during immersion, and the rotation speed is 30 r / min;

[0056] Step 3, placing the soaked quartz tube in a dry atmosphere to dry and remove residual moisture and hydroxide in the tube, the dry atmosphere is a mixed gas composed of oxygen, helium, nitrogen and chlorine, wherein the chlorine flow rate is 100 Sccm, and the drying is completed to obtain a first doped quartz tube;

[0057] Step 4: A mixed gas of 500 sccm of GeCl4 and 200 sccm of O2 is introduced into the first doped quartz tube, and the hydrogen-oxygen lamp moves from right to left at a temperature of 1600° C. to deposit a Ge2O3 layer on the loose layer to obtain a second doped quartz tube;

[0058] Step 5, the second doped quartz tube is sintered into a transparent quartz preform at a high temperature of 2100° C., during which the pressure in the quartz reaction tube is 0.2 Torr, until the quartz reaction tube is completely sintered into a solid quartz preform;

[0059] Step six, insert the quartz preform into the quartz sleeve, and draw it in a drawing tower into a radiation-resistant erbium-doped optical fiber with a core diameter of 5 um and a cladding diameter of 125 um.

[0060] Embodiment 2:

[0061] Embodiment 2 of the present invention provides a method for preparing a radiation-resistant erbium-doped optical fiber. The other steps are the same as those of embodiment 1, except that: the Er of the doping solution selected in step 2 is 3+ ,La 3+ and Al 3+ The configuration concentration is the same as in Example 1, Ga 3+ The preparation concentration is 10~15g / L.

[0062] Embodiment 3:

[0063] Embodiment 3 of the present invention provides a method for preparing a radiation-resistant erbium-doped optical fiber. The other steps are the same as those of Embodiment 1, except that: the Er of the doping solution selected in step 2 is 3+ ,La 3+ and Al 3+ The configuration concentration is the same as in Example 1, Ga 3+ The preparation concentration is 16~25g / L.

[0064] Comparative Example 1:

[0065] Comparative Example 1 provides a method for preparing a radiation-resistant erbium-doped optical fiber. The other steps are the same as those in Example 1, except that the Er doping solution selected in step 2 is 3+ ,La 3+ and Al 3+ The configuration concentration is the same as in Example 1, Ga 3+ The preparation concentration is 0.

[0066] Evaluation test:

[0067] The optical fibers of Examples 1-3 and Comparative Example 1 were irradiated at a dose of 1000 GY. A -20 dBm small signal was used to test the irradiated optical fibers. The optical fiber lengths were optimized to 5-10 m. The laser spectra in the C band (1530-1565 nm) after irradiation were measured as follows: Figure 2 shown.

[0068] Specifically, by Figure 2 It can be seen that the maximum optical power of Examples 1 to 3 of the present invention near 1530-1535 nm after irradiation is significantly greater than the maximum optical power of Comparative Example 1 near 1530-1535 nm after irradiation (about 23.1 dB); the maximum optical power of Examples 1 to 3 of the present invention near 1560 nm after irradiation is significantly greater than the maximum optical power of Comparative Example 1 near 1560 nm after irradiation (about 23 dB); the gain performance of the optical fiber prepared in Examples 1 to 3 of the present invention and Comparative Example 1 is: Example 2> Example 1> Example 3> Comparative Example 1.

[0069] therefore, Figure 2 It shows that in Er-La-Al-Ge co-doped optical fiber, an additional amount of gallium ions (corresponding to Ga in the doping solution) is added 3+ The preparation concentration is 2~25g / L and the optimal concentration is 10~15g / L) which can effectively improve the gain performance of erbium lanthanum aluminum germanium co-doped optical fiber.

[0070] See also Figure 3 , Figure 3 is the background loss diagram of Example 2 of the present invention at 1200nm after irradiation; wherein, Figure 3 As known, the absorption of Example 2 at 1200 nm is 6.6 dB / km, indicating that the background loss of the optical fiber prepared in Example 2 is relatively low.

[0071] Furthermore, the absorption values ​​of Examples 1 to 3 of the present invention and Comparative Example 1 at 1200 nm on the small signal absorption spectrum are shown in Table 1 below:

[0072] Table 1

[0073]

[0074] Specifically, it can be seen from Table 1 that the absorption values ​​of Examples 1~2 of the present invention near 1200nm after irradiation are significantly lower than the absorption value of Comparative Example 1 near 1200nm after irradiation, and the absorption value of Example 3 of the present invention near 1200nm after irradiation is significantly higher than the absorption value of Comparative Example 1 near 1200nm after irradiation.

[0075] Specifically, the results in Table 1 show that: since the lower the absorption value, the lower the background loss, the background loss of the optical fiber prepared in Examples 1 and 2 of the present invention is significantly lower than the background loss of the optical fiber prepared in Comparative Example 1; an appropriate amount of gallium ion doping (corresponding to Ga in the doping solution) 3+ The concentration of gallium ions is 2~15g / L and the optimal concentration is 10~15g / L, which is beneficial to reduce the background loss of optical fiber. The excess gallium ion doping corresponds to the Ga 3+ The preparation concentration is 16~25g / L) which is not conducive to reducing the optical fiber background loss.

[0076] See also Figure 4 , Figure 4 is a noise index diagram of each embodiment of the present invention and the comparative example at the C band after irradiation; Figure 4 It can be seen that the noise level of the radiation-resistant erbium-doped optical fiber prepared in Example 2 of the present invention at the C-band (3.5-4.0 dB) is significantly lower than the noise level of the radiation-resistant erbium-doped optical fiber prepared in Examples 1-2 of the present invention and Comparative Example 1 at the C-band (4.25-5.25 dB).

[0077] Furthermore, the noise index at 1540 nm in the small signal absorption spectrum of Examples 1 to 3 of the present invention and Comparative Example 1 is shown in Table 2 below:

[0078] Table 2

[0079]

[0080] Specifically, it can be seen from Table 2 that the noise index at 1540nm of Example 2 of the present invention after irradiation is significantly lower than the noise index at 1540nm of Comparative Example 1 after irradiation; the noise indexes at 1540nm of Examples 1 to 3 of the present invention after irradiation are significantly higher than the noise index at 1540nm of Comparative Example 1 after irradiation.

[0081] Specifically, the results in Table 2 show that the noise index of the optical fiber prepared in Example 2 of the present invention is significantly lower than the noise index of the optical fiber prepared in Comparative Example 1; the appropriate amount of gallium ion doping (corresponding to Ga in the doping solution) 3+ The concentration of gallium ions is 10~15g / L, which is beneficial to reduce the noise index of optical fiber. Excessive or insufficient gallium ion doping corresponds to the concentration of Ga in the doping solution. 3+ The preparation concentration is 2~5g / L or 16~25g / L) which is not conducive to reducing the noise index of the optical fiber.

[0082] Therefore, in the doping solution of the method for preparing the radiation-resistant erbium-doped optical fiber provided by the present invention, when Er 3+ The preparation concentration is 0.5~0.6g / L, La 3+ The preparation concentration is 15~16g / L, Al 3+The preparation concentration is 45~50g / L, Ga 3+ When the preparation concentration is 10~15g / L, the prepared radiation-resistant erbium-doped optical fiber has excellent radiation resistance as well as good gain performance and low noise coefficient.

[0083] The invention successfully solves the problems of high noise and high loss of radiation-resistant optical fiber by introducing Ga element into the radiation-resistant erbium-doped optical fiber and adjusting the proportion of Er, Al, La, Ge and Si element components.

[0084] The gallium-doped optical fiber provided by the present invention has a wide range of applications in the fields of optical fiber communication, optical fiber sensing, and laser technology. In optical fiber communication, it can be used to build a high-speed, large-capacity optical transmission system. In the field of optical fiber sensing, the high sensitivity and stability of gallium-doped optical fiber make it an ideal sensing material. In laser technology, gallium-doped optical fiber can be used to generate high-power, high-quality laser pulses.

[0085] In summary, different from the prior art, the present invention provides a radiation-resistant erbium-doped optical fiber and a preparation method and application thereof, the method comprising: depositing a loose layer on the inner wall of a quartz reaction tube; immersing the quartz reaction tube in a liquid containing Er; 3+ , Ga 3+ ,La 3+ , Al 3+ The doping solution is dried in a dry atmosphere to obtain a first doped quartz tube. 3+ The concentration of the erbium-doped optical fiber is 0.2-500 g / L; a Ge2O3 layer is deposited on the loose layer of the first doped quartz tube to obtain a second doped quartz tube; the second doped quartz tube is sintered into a quartz preform rod and then inserted into a quartz sleeve, and then drawn into a radiation-resistant erbium-doped optical fiber in a drawing tower; the preparation method of the radiation-resistant erbium-doped optical fiber provided by the present invention comprises the following steps: 3+ , Ga 3 + ,La 3+ and Al 3+ :Er 3+ As a gain medium, it can absorb the pump light energy and convert it into the amplification of the signal light; La 3+ As Er 3+ The dispersant can enhance the radiation resistance of optical fiber, and La 3+ Doping has no negative impact on the gain performance of the optical fiber. 3+ Can adjust Er 3+ The degree of energy level broadening is manifested in the increase of the gain of longer wavelengths in the gain spectrum, and the gain of short wavelengths does not decrease much. 3+The doping can reduce the noise coefficient of the radiation-resistant erbium-doped fiber, while reducing the background loss, further improving the comprehensive performance of the radiation-resistant erbium-doped fiber.

[0086] It should be noted that the above embodiments all belong to the same inventive concept, and the description of each embodiment has its own focus. For matters that are not described in detail in some embodiments, reference may be made to the description in other embodiments.

[0087] The above embodiments only express the implementation methods of the present invention, and the descriptions thereof are relatively specific and detailed, but they cannot be understood as limiting the scope of the invention patent. It should be pointed out that, for those of ordinary skill in the art, several variations and improvements can be made without departing from the concept of the present invention, and these all belong to the protection scope of the present invention. Therefore, the protection scope of the patent of the present invention shall be subject to the attached claims.

Claims

1. A method for preparing a radiation-resistant erbium-doped optical fiber, characterized in that: The following steps are involved: S10, depositing a loose layer on the inner wall of the quartz reaction tube; S20, immersing the quartz reaction tube in a solution containing Er 3+ , Ga 3+ ,La 3+ , Al 3+ and dried in a dry atmosphere to obtain a first doped quartz tube, wherein the doping solution contains Ga 3+ The preparation concentration is 10~15g / L, Er 3+ The preparation concentration is 0.5~2g / L, La 3+ The preparation concentration is 0.2~50g / L, Al 3+ The preparation concentration is 0.2~500g / L; S30, depositing a Ge2O3 layer on the loose layer of the first doped quartz tube to obtain a second doped quartz tube; S40, shrinking the second doped quartz tube into a quartz preform rod, inserting the preform rod into a quartz sleeve, and drawing the preform rod into a radiation-resistant erbium-doped optical fiber in a drawing tower.

2. The method for preparing the radiation-resistant erbium-doped optical fiber according to claim 1, characterized in that: The step S10 specifically includes: the oxyhydrogen lamp moves from left to right, and SiCl4 and O2 are introduced into the quartz reaction tube at 1300-1600° C. simultaneously, so as to obtain the quartz reaction tube having the loose layer.

3. The method for preparing the radiation-resistant erbium-doped optical fiber according to claim 1, characterized in that: In the step S20, the soaking time is 2 to 10 hours, the soaking temperature is 20 to 60° C., and the quartz reaction tube is kept rotating at a speed of 10 r / min to 50 r / min during the soaking process.

4. The method for preparing the radiation-resistant erbium-doped optical fiber according to claim 1, characterized in that: Before performing the step S30, the method further includes: baking the first doped quartz tube in a chlorine atmosphere.

5. The method for preparing the radiation-resistant erbium-doped optical fiber according to claim 1, characterized in that: The step S30 specifically includes: the oxyhydrogen lamp moves from right to left, and GeCl4 and O2 are introduced into the first doped quartz tube at 1300-1700° C. to obtain a second doped quartz tube.

6. The method for preparing the radiation-resistant erbium-doped optical fiber according to claim 1, characterized in that: In the step S40, the temperature for shrinking the second doped quartz tube is 1900-2300° C., and the pressure inside the second doped quartz tube during shrinking is 0.1-0.3 Torr.

7. A radiation-resistant erbium-doped optical fiber, characterized in that: The radiation-resistant erbium-doped optical fiber is prepared by the method for preparing the radiation-resistant erbium-doped optical fiber according to any one of claims 1 to 6.

8. Use of the radiation-resistant erbium-doped optical fiber as claimed in claim 7 under the condition that the irradiation dose is greater than or equal to 1000 GY.

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