WO2022247395A1 - 掺铒光纤和掺铒光纤的制备方法 - Google Patents

掺铒光纤和掺铒光纤的制备方法 Download PDF

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Publication number
WO2022247395A1
WO2022247395A1 PCT/CN2022/080265 CN2022080265W WO2022247395A1 WO 2022247395 A1 WO2022247395 A1 WO 2022247395A1 CN 2022080265 W CN2022080265 W CN 2022080265W WO 2022247395 A1 WO2022247395 A1 WO 2022247395A1
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Prior art keywords
erbium
layer
doping concentration
optical fiber
doped
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French (fr)
Inventor
刘业辉
操时宜
李进延
褚应波
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Huawei Technologies Co Ltd
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Huawei Technologies Co Ltd
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Priority to EP22810129.1A priority Critical patent/EP4336680A4/en
Publication of WO2022247395A1 publication Critical patent/WO2022247395A1/zh
Priority to US18/519,189 priority patent/US20240097395A1/en
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    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04B—TRANSMISSION
    • H04B10/00—Transmission systems employing electromagnetic waves other than radio-waves, e.g. infrared, visible or ultraviolet light, or employing corpuscular radiation, e.g. quantum communication
    • H04B10/29—Repeaters
    • H04B10/291—Repeaters in which processing or amplification is carried out without conversion of the main signal from optical form
    • H04B10/2912—Repeaters in which processing or amplification is carried out without conversion of the main signal from optical form characterised by the medium used for amplification or processing
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01S—DEVICES USING THE PROCESS OF LIGHT AMPLIFICATION BY STIMULATED EMISSION OF RADIATION [LASER] TO AMPLIFY OR GENERATE LIGHT; DEVICES USING STIMULATED EMISSION OF ELECTROMAGNETIC RADIATION IN WAVE RANGES OTHER THAN OPTICAL
    • H01S3/00—Lasers, i.e. devices using stimulated emission of electromagnetic radiation in the infrared, visible or ultraviolet wave range
    • H01S3/05—Construction or shape of optical resonators; Accommodation of active medium therein; Shape of active medium
    • H01S3/06—Construction or shape of active medium
    • H01S3/063—Waveguide lasers, i.e. whereby the dimensions of the waveguide are of the order of the light wavelength
    • H01S3/067—Fibre lasers
    • H01S3/06708—Constructional details of the fibre, e.g. compositions, cross-section, shape or tapering
    • H01S3/06716—Fibre compositions or doping with active elements
    • C—CHEMISTRY; METALLURGY
    • C03—GLASS; MINERAL OR SLAG WOOL
    • C03B—MANUFACTURE, SHAPING, OR SUPPLEMENTARY PROCESSES
    • C03B37/00—Manufacture or treatment of flakes, fibres, or filaments from softened glass, minerals, or slags
    • C03B37/01—Manufacture of glass fibres or filaments
    • C03B37/012—Manufacture of preforms for drawing fibres or filaments
    • C03B37/01205—Manufacture of preforms for drawing fibres or filaments starting from tubes, rods, fibres or filaments
    • C03B37/01262—Depositing additional preform material as liquids or solutions, e.g. solution doping of preform tubes or rods
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01S—DEVICES USING THE PROCESS OF LIGHT AMPLIFICATION BY STIMULATED EMISSION OF RADIATION [LASER] TO AMPLIFY OR GENERATE LIGHT; DEVICES USING STIMULATED EMISSION OF ELECTROMAGNETIC RADIATION IN WAVE RANGES OTHER THAN OPTICAL
    • H01S3/00—Lasers, i.e. devices using stimulated emission of electromagnetic radiation in the infrared, visible or ultraviolet wave range
    • H01S3/05—Construction or shape of optical resonators; Accommodation of active medium therein; Shape of active medium
    • H01S3/06—Construction or shape of active medium
    • H01S3/063—Waveguide lasers, i.e. whereby the dimensions of the waveguide are of the order of the light wavelength
    • H01S3/067—Fibre lasers
    • H01S3/06708—Constructional details of the fibre, e.g. compositions, cross-section, shape or tapering
    • H01S3/0672—Non-uniform radial doping
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01S—DEVICES USING THE PROCESS OF LIGHT AMPLIFICATION BY STIMULATED EMISSION OF RADIATION [LASER] TO AMPLIFY OR GENERATE LIGHT; DEVICES USING STIMULATED EMISSION OF ELECTROMAGNETIC RADIATION IN WAVE RANGES OTHER THAN OPTICAL
    • H01S3/00—Lasers, i.e. devices using stimulated emission of electromagnetic radiation in the infrared, visible or ultraviolet wave range
    • H01S3/05—Construction or shape of optical resonators; Accommodation of active medium therein; Shape of active medium
    • H01S3/06—Construction or shape of active medium
    • H01S3/063—Waveguide lasers, i.e. whereby the dimensions of the waveguide are of the order of the light wavelength
    • H01S3/067—Fibre lasers
    • H01S3/06708—Constructional details of the fibre, e.g. compositions, cross-section, shape or tapering
    • H01S3/06729—Peculiar transverse fibre profile
    • H01S3/06733—Fibre having more than one cladding
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01S—DEVICES USING THE PROCESS OF LIGHT AMPLIFICATION BY STIMULATED EMISSION OF RADIATION [LASER] TO AMPLIFY OR GENERATE LIGHT; DEVICES USING STIMULATED EMISSION OF ELECTROMAGNETIC RADIATION IN WAVE RANGES OTHER THAN OPTICAL
    • H01S3/00—Lasers, i.e. devices using stimulated emission of electromagnetic radiation in the infrared, visible or ultraviolet wave range
    • H01S3/05—Construction or shape of optical resonators; Accommodation of active medium therein; Shape of active medium
    • H01S3/06—Construction or shape of active medium
    • H01S3/063—Waveguide lasers, i.e. whereby the dimensions of the waveguide are of the order of the light wavelength
    • H01S3/067—Fibre lasers
    • H01S3/06754—Fibre amplifiers
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01S—DEVICES USING THE PROCESS OF LIGHT AMPLIFICATION BY STIMULATED EMISSION OF RADIATION [LASER] TO AMPLIFY OR GENERATE LIGHT; DEVICES USING STIMULATED EMISSION OF ELECTROMAGNETIC RADIATION IN WAVE RANGES OTHER THAN OPTICAL
    • H01S3/00—Lasers, i.e. devices using stimulated emission of electromagnetic radiation in the infrared, visible or ultraviolet wave range
    • H01S3/05—Construction or shape of optical resonators; Accommodation of active medium therein; Shape of active medium
    • H01S3/06—Construction or shape of active medium
    • H01S3/063—Waveguide lasers, i.e. whereby the dimensions of the waveguide are of the order of the light wavelength
    • H01S3/067—Fibre lasers
    • H01S3/06754—Fibre amplifiers
    • H01S3/06758—Tandem amplifiers
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01S—DEVICES USING THE PROCESS OF LIGHT AMPLIFICATION BY STIMULATED EMISSION OF RADIATION [LASER] TO AMPLIFY OR GENERATE LIGHT; DEVICES USING STIMULATED EMISSION OF ELECTROMAGNETIC RADIATION IN WAVE RANGES OTHER THAN OPTICAL
    • H01S3/00—Lasers, i.e. devices using stimulated emission of electromagnetic radiation in the infrared, visible or ultraviolet wave range
    • H01S3/09—Processes or apparatus for excitation, e.g. pumping
    • H01S3/091—Processes or apparatus for excitation, e.g. pumping using optical pumping
    • H01S3/094—Processes or apparatus for excitation, e.g. pumping using optical pumping by coherent light
    • H01S3/094003—Processes or apparatus for excitation, e.g. pumping using optical pumping by coherent light the pumped medium being a fibre
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01S—DEVICES USING THE PROCESS OF LIGHT AMPLIFICATION BY STIMULATED EMISSION OF RADIATION [LASER] TO AMPLIFY OR GENERATE LIGHT; DEVICES USING STIMULATED EMISSION OF ELECTROMAGNETIC RADIATION IN WAVE RANGES OTHER THAN OPTICAL
    • H01S3/00—Lasers, i.e. devices using stimulated emission of electromagnetic radiation in the infrared, visible or ultraviolet wave range
    • H01S3/14—Lasers, i.e. devices using stimulated emission of electromagnetic radiation in the infrared, visible or ultraviolet wave range characterised by the material used as the active medium
    • H01S3/16—Solid materials
    • H01S3/1601—Solid materials characterised by an active (lasing) ion
    • H01S3/1603—Solid materials characterised by an active (lasing) ion rare earth
    • H01S3/1608—Solid materials characterised by an active (lasing) ion rare earth erbium
    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04B—TRANSMISSION
    • H04B10/00—Transmission systems employing electromagnetic waves other than radio-waves, e.g. infrared, visible or ultraviolet light, or employing corpuscular radiation, e.g. quantum communication
    • H04B10/25—Arrangements specific to fibre transmission
    • H04B10/2507—Arrangements specific to fibre transmission for the reduction or elimination of distortion or dispersion
    • C—CHEMISTRY; METALLURGY
    • C03—GLASS; MINERAL OR SLAG WOOL
    • C03B—MANUFACTURE, SHAPING, OR SUPPLEMENTARY PROCESSES
    • C03B2201/00—Type of glass produced
    • C03B2201/06—Doped silica-based glasses
    • C03B2201/30—Doped silica-based glasses doped with metals, e.g. Ga, Sn, Sb, Pb or Bi
    • C03B2201/34—Doped silica-based glasses doped with metals, e.g. Ga, Sn, Sb, Pb or Bi doped with rare earth metals, i.e. with Sc, Y or lanthanides, e.g. for laser-amplifiers
    • C—CHEMISTRY; METALLURGY
    • C03—GLASS; MINERAL OR SLAG WOOL
    • C03B—MANUFACTURE, SHAPING, OR SUPPLEMENTARY PROCESSES
    • C03B2203/00—Fibre product details, e.g. structure, shape
    • C03B2203/10—Internal structure or shape details
    • C03B2203/14—Non-solid, i.e. hollow products, e.g. hollow clad or with core-clad interface
    • C03B2203/16—Hollow core
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01S—DEVICES USING THE PROCESS OF LIGHT AMPLIFICATION BY STIMULATED EMISSION OF RADIATION [LASER] TO AMPLIFY OR GENERATE LIGHT; DEVICES USING STIMULATED EMISSION OF ELECTROMAGNETIC RADIATION IN WAVE RANGES OTHER THAN OPTICAL
    • H01S2301/00—Functional characteristics
    • H01S2301/02—ASE (amplified spontaneous emission), noise; Reduction thereof
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01S—DEVICES USING THE PROCESS OF LIGHT AMPLIFICATION BY STIMULATED EMISSION OF RADIATION [LASER] TO AMPLIFY OR GENERATE LIGHT; DEVICES USING STIMULATED EMISSION OF ELECTROMAGNETIC RADIATION IN WAVE RANGES OTHER THAN OPTICAL
    • H01S3/00—Lasers, i.e. devices using stimulated emission of electromagnetic radiation in the infrared, visible or ultraviolet wave range
    • H01S3/05—Construction or shape of optical resonators; Accommodation of active medium therein; Shape of active medium
    • H01S3/06—Construction or shape of active medium
    • H01S3/063—Waveguide lasers, i.e. whereby the dimensions of the waveguide are of the order of the light wavelength
    • H01S3/067—Fibre lasers
    • H01S3/06708—Constructional details of the fibre, e.g. compositions, cross-section, shape or tapering
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01S—DEVICES USING THE PROCESS OF LIGHT AMPLIFICATION BY STIMULATED EMISSION OF RADIATION [LASER] TO AMPLIFY OR GENERATE LIGHT; DEVICES USING STIMULATED EMISSION OF ELECTROMAGNETIC RADIATION IN WAVE RANGES OTHER THAN OPTICAL
    • H01S3/00—Lasers, i.e. devices using stimulated emission of electromagnetic radiation in the infrared, visible or ultraviolet wave range
    • H01S3/05—Construction or shape of optical resonators; Accommodation of active medium therein; Shape of active medium
    • H01S3/06—Construction or shape of active medium
    • H01S3/063—Waveguide lasers, i.e. whereby the dimensions of the waveguide are of the order of the light wavelength
    • H01S3/067—Fibre lasers
    • H01S3/06754—Fibre amplifiers
    • H01S3/06762—Fibre amplifiers having a specific amplification band
    • H01S3/06766—C-band amplifiers, i.e. amplification in the range of about 1530 nm to 1560 nm
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01S—DEVICES USING THE PROCESS OF LIGHT AMPLIFICATION BY STIMULATED EMISSION OF RADIATION [LASER] TO AMPLIFY OR GENERATE LIGHT; DEVICES USING STIMULATED EMISSION OF ELECTROMAGNETIC RADIATION IN WAVE RANGES OTHER THAN OPTICAL
    • H01S3/00—Lasers, i.e. devices using stimulated emission of electromagnetic radiation in the infrared, visible or ultraviolet wave range
    • H01S3/05—Construction or shape of optical resonators; Accommodation of active medium therein; Shape of active medium
    • H01S3/06—Construction or shape of active medium
    • H01S3/063—Waveguide lasers, i.e. whereby the dimensions of the waveguide are of the order of the light wavelength
    • H01S3/067—Fibre lasers
    • H01S3/06754—Fibre amplifiers
    • H01S3/06762—Fibre amplifiers having a specific amplification band
    • H01S3/0677—L-band amplifiers, i.e. amplification in the range of about 1560 nm to 1610 nm

Definitions

  • the application relates to the fields of amplifiers, optical communications and preparation of rare earth-doped optical fibers, in particular to an erbium-doped optical fiber and a preparation method of an erbium-doped optical fiber.
  • an EDFA includes a pump light source, an optical coupler and an erbium-doped optical fiber.
  • the pump light source is used to generate pump light.
  • Optical couplers are used to couple signal light and pump light into erbium-doped fibers.
  • the pump light is used as the excitation source of the signal light to amplify the signal light.
  • the erbium-doped fiber will produce amplified spontaneous emission (Amplified spontaneous emission, ASE) under the action of the excitation source.
  • ASE will increase the noise figure of the erbium-doped fiber and affect the communication quality.
  • the application provides an erbium-doped optical fiber and a preparation method for the erbium-doped optical fiber.
  • the ASE can be reduced, thereby reducing the noise figure of the erbium-doped optical fiber and improving the communication quality.
  • the first aspect of the present application provides an erbium-doped optical fiber.
  • the core of the erbium-doped fiber includes the first layer and the second layer from the inside to the outside.
  • the first layer includes the center of the core.
  • the second layer is annular, and the outer ring of the ring is the outer ring of the fiber core.
  • the average doping concentration of erbium ions in the first layer is higher than the average doping concentration of erbium ions in the second layer.
  • the ASE can be reduced, thereby reducing the noise figure of the erbium-doped optical fiber and improving the communication quality.
  • the average doping concentration of erbium ions in the first layer is higher than the average doping concentration of erbium ions in the second layer.
  • the erbium-doped fiber is used in the L-band.
  • the L-band erbium-doped optical fiber has a higher concentration of erbium ions. Therefore, the erbium-doped optical fiber in this application can further reduce the noise system and improve the communication quality.
  • the average doping concentration of erbium ions in the first layer is higher than the average doping concentration of erbium ions in the second layer by more than M percent, and M is greater than or equal to 30.
  • M is greater than or equal to 30.
  • the value of M is between 30 and 75.6.
  • the ratio of the average concentration of erbium ions in the first layer and the second layer is continuously increased, the gain of the erbium-doped optical fiber to signal light will be reduced.
  • the application limits the value of M to be less than 75.6, which can reduce the noise figure of the erbium-doped fiber on the basis of reducing the gain as little as possible.
  • the cross-sectional area of the first layer is within N percent of the cross-sectional area of the fiber core, and N is less than or equal to 50.
  • N is less than or equal to 50.
  • the noise figure of the erbium-doped fiber can be effectively reduced, for example, the noise figure of the erbium-doped fiber can reach below 5.5 dB.
  • the value of N is between 20 and 50.
  • the gain of the erbium-doped fiber to the signal light will be reduced.
  • the average doping concentration of erbium ions in the first layer is between 2742 parts per million (ppm) and 2966 ppm.
  • the average doping concentration of erbium ions in the second layer is between 1560ppm and 2280ppm.
  • the first layer includes K sublayers, where K is an integer greater than 1.
  • the second layer includes P sublayers, where P is an integer greater than 0.
  • the doping concentration of erbium ions in the K sublayers and P sublayers gradually decreases.
  • the distribution of light intensity in the fiber core is a Gaussian distribution. The closer the distribution of erbium ions in the fiber core is to Gaussian distribution, the more effective the noise figure of the fiber can be.
  • the fiber core is divided into K+P sublayers.
  • the present application can more effectively reduce the noise figure of the erbium-doped optical fiber.
  • K and P are 2.
  • the K sublayers include a first sublayer and a second sublayer.
  • the P sublayers include a third sublayer and a fourth sublayer.
  • the erbium ion doping concentration range of the first sublayer is between 2687ppm and 3087ppm.
  • the erbium ion doping concentration range of the second sublayer is between 2006ppm and 2406ppm.
  • the erbium ion doping concentration range of the third sublayer is between 1028ppm and 1428ppm.
  • the erbium ion doping concentration range of the fourth sublayer is between 301ppm and 701ppm.
  • the doping concentration of erbium ions at the center of the fiber core is between 1500 ppm and 4000 ppm. r2
  • the doping concentration of erbium ions in the fiber core satisfies the following relationship: Wherein, A is the doping concentration of erbium ions at the center of the fiber core. C(r) is the doping concentration of erbium ions at the target point. r is the distance from the target point to the center of the fiber core, and ⁇ is a correction factor for negative values.
  • the radius of the fiber core is between 0.01 micron and 0.3 micron.
  • the erbium-doped optical fiber includes a core and a cladding from the inside to the outside.
  • the second aspect of the present application provides a method for preparing an erbium-doped optical fiber.
  • the manufacture method of erbium-doped optical fiber comprises the following steps:
  • a soot layer is deposited inside the substrate tube, which is immersed in a solution of erbium ions.
  • the loose layer is taken out from the erbium ion solution, dried and vitrified to obtain a glass rod.
  • Z is an integer greater than 1.
  • the glass rod is sintered into a solid glass rod.
  • the solid glass rods were fabricated into erbium-doped optical fibers.
  • Z is 4.
  • the more layers there are in the sub-layers of the fiber core the closer the distribution of erbium ions in the fiber core is to a Gaussian distribution.
  • the more layers there are in the sub-layers of the fiber core the higher the processing cost of the fiber core. This application limits the number of layers of the fiber core to 4, which can reduce the noise figure of the erbium-doped optical fiber on the basis of reducing the processing cost as much as possible.
  • the concentrations of the Z-time erbium ion solutions are Y1, Y2, Y3 and Y4 mol/L respectively.
  • the difference between Y2 and Y1 is between 0.001mol/L and 0.004mol/L.
  • the difference between Y3 and Y2 is between 0.004mol/L and 0.01mol/L.
  • the difference between Y4 and Y3 is between 0.01mol/L and 0.016mol/L.
  • the third aspect of the present application provides an erbium-doped fiber amplifier EDFA.
  • the EDFA includes a pumping light source, an optical coupler, and the erbium-doped optical fiber described in the first aspect or any optional mode of the first aspect.
  • the pumping light source is used to generate pumping light.
  • the optical coupler is used to receive signal light and pump light, and couple the signal light and pump light into the erbium-doped fiber.
  • Erbium-doped fiber is used to amplify signal light under the action of pump light.
  • the fourth aspect of the present application provides an optical communication system.
  • the optical communication system includes a sending end, a receiving end and the EDFA described in the aforementioned third aspect.
  • the sending end is used to transmit signal light to the receiving end through the optical fiber.
  • the optical fiber is connected with the EDFA; the EDFA is used to generate pumping light and amplify the signal light according to the pumping light.
  • the receiving end is used to receive the amplified signal light.
  • Fig. 1 is the distribution schematic diagram of erbium ion in the fiber core
  • Fig. 2 is the first distribution schematic diagram of the erbium ions provided in the application in the fiber core;
  • Fig. 3 is the first schematic structural view of the fiber core provided in this application.
  • Fig. 4 is the second structural schematic view of the fiber core provided in this application.
  • Fig. 5 is the third schematic structural view of the fiber core provided in this application.
  • Fig. 6 is the fourth schematic structural view of the fiber core provided in this application.
  • FIG. 7 is a first structural schematic diagram of the optical communication system provided in this application.
  • Fig. 8 is the distribution schematic diagram of the noise figure of erbium-doped optical fiber on different wavelengths
  • Fig. 9 is the first distribution schematic diagram of the noise figure of the erbium-doped optical fiber provided in the present application.
  • Fig. 10 is the second distribution schematic diagram of the noise figure of the erbium-doped fiber provided in the present application.
  • Fig. 11 is the second schematic diagram of the distribution of erbium ions in the fiber core provided in the present application.
  • Figure 12 is a schematic structural view of the erbium-doped optical fiber provided in the present application during the preparation process
  • FIG. 13 is a schematic structural diagram of the EDFA provided in this application.
  • Fig. 14 is a second structural schematic diagram of the optical communication system provided in this application.
  • the application provides an erbium-doped optical fiber and a preparation method for the erbium-doped optical fiber.
  • the ASE can be reduced, thereby reducing the noise figure of the erbium-doped optical fiber and improving the communication quality.
  • first”, “second” and the like used in this application are only used for the purpose of distinguishing description, and cannot be interpreted as indicating or implying relative importance, nor can they be understood as indicating or implying order.
  • reference numerals and/or letters are repeated in the various figures of this application for the sake of brevity and clarity. Repetition does not imply a strictly limited relationship between the various embodiments and/or configurations.
  • the erbium-doped optical fiber in this application is used in the field of optical communication.
  • the erbium-doped fiber in the amplifier is used to amplify the signal light under the action of the excitation source. Signal light is transmitted in the core of the erbium-doped fiber.
  • the amplifier will produce a large noise figure.
  • FIG. 1 is a schematic diagram of the distribution of erbium ions in the fiber core. As shown in FIG. 1 , the abscissa is the position of the fiber core, and the unit is micron ⁇ m. In Figure 1, the center of the core is located at coordinate 0.
  • the core has a radius of 2.5 microns and a diameter of 5 microns.
  • the ordinate is the doping concentration of erbium ions in the fiber core, and the unit is ppm. Erbium ions are evenly distributed in the core. Therefore, the concentration 101 is a straight line. It should be understood that, in the actual processing process, the concentration of each point in the fiber core cannot be guaranteed to be the same due to the processing technology. Therefore, the concentration 101 can also be a curve fluctuating up and down.
  • the erbium ions in the fiber core transition from the ground state to the upper energy level.
  • the signal light is injected into the fiber core, the light intensity of the signal light is mainly distributed in the inner layer of the fiber core.
  • the upper-level erbium ions in the inner layer generate stimulated emission, thereby amplifying the signal light.
  • the upper-level erbium ions cannot obtain enough signal light for stimulated emission, and spontaneously transition from the excited state to the ground state, resulting in ASE.
  • ASE is a major source of noise in amplifiers or erbium-doped fibers.
  • the calculation formula of the noise factor NF is as follows.
  • P ASE is the noise power of the amplifier or erbium-doped fiber, and the noise power is produced by ASE.
  • h Planck's constant.
  • v is the signal light frequency.
  • B is the detection line width of the spectrometer.
  • G is the gain of the amplifier.
  • NF is strongly related to the PASE of the amplifier. Specifically, the larger the PASE , the larger the NF; the smaller the PASE , the smaller the NF. Therefore, when the outer layer of the core generates a large amount of ASE, the erbium-doped fiber will produce a large noise figure.
  • the present application provides an erbium-doped optical fiber.
  • the doping concentration of erbium ions in the outer layer is reduced, thereby reducing ASE and reducing the noise figure of the erbium-doped optical fiber.
  • the average doping concentration of erbium ions in the inner layer of the fiber core is higher than the average doping concentration of erbium ions in the outer layer of the fiber core.
  • FIG. 2 is the first schematic diagram of distribution of erbium ions in the fiber core provided in this application. As shown in FIG. 2 , the average doping concentration of erbium ions in the inner layer of the fiber core is 201.
  • the average doping concentration of erbium ions in the outer layer of the fiber core is 202.
  • Concentration 202 is less than concentration 201 . It should be understood that, in the actual processing process, the concentration of each point in the fiber core cannot be guaranteed to be the same due to the processing technology. Therefore, the concentration 201 and the concentration 201 can also be a curve fluctuating up and down. Similarly, in the subsequent description, "the doping concentration of erbium ions in the first sublayer is the same" means “the doping concentration of erbium ions in the first sublayer is approximately the same".
  • Fig. 3 is a schematic diagram of the first structure of the fiber core provided in this application.
  • the fiber core includes a first layer 301 and a second layer 302 .
  • the first layer 301 is also referred to as an inner layer
  • the second layer 302 is also referred to as an outer layer.
  • the first layer 301 may be circular.
  • the first layer 301 comprises the center of the fiber core.
  • the second layer is circular.
  • the outer ring of the ring is the outer ring of the core.
  • the average doping concentration of erbium ions in the first layer 301 is higher than the average doping concentration of erbium ions in the second layer 302 .
  • the boundary line between the first layer 301 and the second layer 302 may overlap with the boundary line between the two sublayers, or may not overlap.
  • the two sublayers include a first sublayer and a second sublayer.
  • the first layer 301 is the first sub-layer
  • the second layer 302 is the second sub-layer.
  • the doping concentration of erbium ions in the first sublayer is the same.
  • the doping concentration of erbium ions in the second sublayer is the same.
  • the doping concentration of erbium ions in the first sublayer is greater than that in the second sublayer, there is a sudden change in the doping concentration of erbium ions at the boundary line.
  • FIG. 4 is a second structural schematic diagram of the fiber core provided in this application.
  • the fiber core includes a first boundary line 401 and a second boundary line 402 .
  • the first boundary line 401 divides the fiber core into a first sublayer and a second sublayer.
  • the first sub-layer is within the first boundary line 401, and the doping concentration of erbium ions in the first sub-layer is the same.
  • the second sublayer is outside the second boundary line 401 , and the doping concentration of erbium ions in the second sublayer is the same.
  • the erbium ion doping concentration of the first sublayer is higher than the erbium ion doping concentration of the second sublayer. Therefore, at the first boundary line 401, there is a sudden change in the doping concentration of erbium ions.
  • the second boundary line 402 divides the fiber core into a first layer and a second layer.
  • the first layer is within the second boundary line 402
  • the second layer is outside the second boundary line 402 .
  • the average doping concentration of erbium ions in the first layer is higher than the average doping concentration of erbium ions in the second layer.
  • the second boundary line 402 is in the first sublayer, and there is no abrupt change in the doping concentration of erbium ions at the second boundary line 402 .
  • the layer boundary line is the boundary line between "layer” and "layer”
  • the sub-layer boundary line is the boundary line between "sub-layer” and "sub-layer”.
  • the solid line represents the boundary line or boundary line where there is a sudden change in the doping concentration of erbium ions, and the two sides of the solid line belong to different "sub-layers".
  • sub-layer please also refer to the description of the sub-layer in the subsequent preparation method of erbium-doped optical fiber.
  • the sides of the dashed line belong to different "layers”.
  • Fig. 5 is a schematic diagram of the third structure of the fiber core provided in this application.
  • the fiber core includes a first layer 301 and a second layer 302 .
  • the first layer 301 comprises the center of the fiber core.
  • the outer ring of the second layer 302 is the outer ring of the core.
  • the average doping concentration of erbium ions in the first layer 301 is higher than the average doping concentration of erbium ions in the second layer 302 .
  • the core includes further layers between the first layer and the second layer.
  • the fiber core further includes a third layer 501 .
  • the third layer 501 is between the first layer 301 and the second layer 302 .
  • the average doping concentration of erbium ions in the third layer 501 is lower than that of the first layer 301
  • the average doping concentration of erbium ions in the second layer 302 is lower than that of the third layer 501 .
  • a "layer” may include one or more "sub-layers".
  • the first layer includes K sub-layers, where K is an integer greater than 0.
  • K is an integer greater than 1.
  • the second layer includes P sublayers, where P is an integer greater than 0.
  • the distribution of light intensity in the fiber core is a Gaussian distribution. The closer the distribution of erbium ions in the fiber core is to the Gaussian distribution, the more effectively the noise figure of the erbium-doped fiber can be reduced.
  • the present application can define that along the center of the fiber core from inside to outside, the doping concentration of erbium ions in the K+P sublayers gradually decreases, so that the distribution of erbium ions in the fiber core is close to the Gaussian distribution.
  • FIG. 6 is a fourth structural schematic diagram of the fiber core provided in this application. As shown in FIG.
  • the fiber core includes a first sublayer 601 , a second sublayer 602 , a third sublayer 603 and a fourth sublayer 604 .
  • the first sublayer 601 and the second sublayer 602 belong to the first layer.
  • the third sublayer 603 and the fourth sublayer 604 belong to the second layer.
  • the doping concentration of erbium ions in the first sublayer 601 , the second sublayer 602 , the third sublayer 603 and the fourth sublayer 604 gradually decreases.
  • the erbium-doped fiber of the present application is used in the L-band.
  • the gain coefficient of L-wave-cut signal light in the erbium-doped fiber is relatively low. Therefore, in order to increase the gain of the erbium-doped fiber amplifier, it is necessary to increase the doping concentration of erbium ions in the erbium-doped fiber.
  • the erbium ion doping concentration of the erbium-doped fiber is generally 300ppm to 500ppm.
  • the erbium ion doping concentration of the erbium-doped fiber generally needs to be greater than 1500ppm.
  • the outer layer of the erbium-doped fiber has more erbium ions. More erbium ions produce a larger ASE and thus a larger noise figure.
  • the noise figure of the C-band erbium-doped fiber amplifier is generally less than 5dB.
  • the noise figure of the erbium-doped fiber amplifier in the L-band is generally greater than 6dB. Therefore, in the L-band, it is more necessary to reduce the doping concentration of erbium ions in the outer layer of the erbium-doped optical fiber to reduce the noise figure.
  • Fig. 7 is a first structural schematic diagram of the optical communication system provided in this application.
  • the optical communication system includes an optical amplifier 701 , an optical amplifier 705 , an optical amplifier 709 and an optical spectrum analyzer (optical spectrum analyzers, OSA) 713 .
  • the optical amplifier 701 includes a pump light source 704, a wavelength division multiplexer (Wavelength Division Multiplexing, WDM) 703 and an erbium-doped optical fiber 702.
  • WDM wavelength division multiplexer
  • the pump light source 704 is used to generate pump light.
  • WDM 703 is used to couple signal light and pump light into erbium-doped fiber 702.
  • the pump light is used as an excitation source of the signal light to amplify the signal light.
  • the optical amplifier 705 includes a pump light source 708, a wavelength division multiplexer WDM 707 and an erbium-doped optical fiber 706.
  • the optical amplifier 709 includes a pump light source 712, a wavelength division multiplexer WDM 711 and an erbium-doped optical fiber 710.
  • OSA 713 is used to measure the optical noise figure of the three-stage amplified signal.
  • Fig. 8 is a schematic diagram showing the distribution of noise figures of Erbium-doped optical fibers at different wavelengths. As shown in FIG. 8, the abscissa is the wavelength, and the unit is nanometer nm. The y-coordinate is the noise figure in dB. In the range of 1575nm to 1618nm, the maximum noise figure of the amplifier is 6.6dB, and the average noise figure is about 6.3dB.
  • the noise figure of the erbium-doped fiber amplifier in this application is measured using the optical communication system in FIG. 7 .
  • the schematic diagram of the structure of the erbium-doped fiber is shown in Fig. 3 .
  • the area of the first layer 301 accounts for 50% of the core area.
  • the average doping concentration of erbium ions in the first layer 301 is 2742ppm.
  • the average doping concentration of erbium ions in the second layer 302 is 1560 ppm.
  • the average doping concentration of erbium ions in the first layer 301 is 75.6% higher than the average doping concentration of erbium ions in the second layer 302 .
  • Fig. 9 is a schematic diagram of the first distribution of the noise figure of the erbium-doped optical fiber provided in this application. As shown in Figure 9, within the range of 1575nm to 1618nm, the maximum noise figure of the erbium-doped fiber amplifier is 5.2dB, and the average noise figure is less than 5dB.
  • the area of the first layer 301 accounts for 20% of the core area.
  • the average doping concentration of erbium ions in the first layer 301 is 2966ppm.
  • the average doping concentration of erbium ions in the second layer 302 is 2280 ppm.
  • the average doping concentration of erbium ions in the first layer 301 is 30% higher than the average doping concentration of erbium ions in the second layer 302 .
  • Fig. 10 is a second schematic diagram of the distribution of the noise figure of the erbium-doped optical fiber provided in this application. As shown in Figure 10, within the range of 1575nm to 1618nm, the maximum noise figure of the erbium-doped fiber amplifier is 5.4dB, and the average noise figure is less than 5.2dB.
  • the average doping concentration of erbium ions in the first layer is higher than the average doping concentration of erbium ions in the second layer by more than M percent. It can be seen from the above experiments that when the value of M is between 30 and 75.6, the average noise figure of the erbium-doped fiber amplifier is less than 5.5 dB. It is defined that the cross-sectional area of the first layer is within N percent of the cross-sectional area of the fiber core. It can be seen from the above experiments that when the value of N is between 20 and 50, the average noise figure of the erbium-doped fiber amplifier is less than 5.5 dB.
  • the average noise figure of the erbium-doped fiber amplifier is less than 5.5dB.
  • the area of the first sublayer 601 accounts for 19% of the core area, and the doping concentration of erbium ions in the first sublayer 601 is 2887ppm.
  • the area of the second sublayer 602 accounts for 26% of the core area, and the doping concentration of erbium ions in the second sublayer 602 is 2206ppm.
  • the area of the third sublayer 603 accounts for 27% of the core area, and the doping concentration of erbium ions in the third sublayer 603 is 1228ppm.
  • the area of the fourth sublayer 604 accounts for 28% of the core area, and the doping concentration of erbium ions in the fourth sublayer 604 is 501ppm. Since there may be errors in the process of fiber core processing, the error is defined as plus or minus 200ppm. At this time, the doping concentration of erbium ions in the first sub-layer 601 ranges from 2687ppm to 3087ppm. The doping concentration of Er ions in the second sub-layer 602 ranges from 2006 ppm to 2406 ppm. The doping concentration of erbium ions in the third sub-layer 603 ranges from 1028 ppm to 1428 ppm. The doping concentration of erbium ions in the fourth sub-layer 604 ranges from 301 ppm to 701 ppm.
  • the distribution of erbium ions in the fiber core is realized as a Gaussian distribution by increasing the number of neutron layers in the fiber core.
  • the doping concentration of erbium ions in the fiber core satisfies the following relationship.
  • A is the doping concentration of erbium ions at the center of the fiber core.
  • A ranges from 1500ppm to 4000ppm.
  • C(r) is the doping concentration of erbium ions at the target point.
  • r is the distance from the target point to the center of the fiber core.
  • r is less than or equal to R.
  • R is the radius of the core.
  • R ranges from 0.01 microns to 0.3 microns.
  • ⁇ is a correction factor for negative values.
  • FIG. 11 is a second schematic diagram of the distribution of erbium ions in the fiber core provided in this application. As shown in Figure 11, when R is equal to 2.5, A is equal to 3000, and ⁇ is equal to negative 0.5, the distribution of erbium ions in the fiber core tends to a Gaussian distribution.
  • the above describes the erbium-doped optical fiber in this application.
  • the preparation method of the erbium-doped optical fiber in this application is described below.
  • the preparation method of erbium-doped optical fiber includes the following steps.
  • step one a loose layer is deposited in the substrate tube, and the loose layer is immersed in an erbium ion solution.
  • the substrate tube is pretreated to preheat the substrate tube and effectively eliminate impurities and air bubbles on the inner wall of the substrate tube.
  • the raw material is fed into the base pipe through the MCVD equipment.
  • the raw materials Under the heating condition of the heat source hydrogen-oxygen torch, the raw materials undergo a chemical reaction to produce fine particles such as silicon dioxide, phosphorus pentoxide, silicon oxyfluoride, and boron trioxide.
  • fine particles are deposited and attached to the inner surface of the substrate tube.
  • a lower heating temperature for example, 1300° C. to 1500° C.
  • a white opaque porous loose layer will be formed, and a porous loose layer with a length between 150 mm and 300 mm will be formed.
  • the rare earth co-doped raw materials are dissolved in alcohol or hydrochloric acid solution according to a specific ratio to obtain a mixed solution.
  • the mixed solution erbium ions Er3+, phosphorus ions P5+, aluminum ions Al3+, lanthanum La3+ and other ions are included. Therefore, the mixed solution is also called the erbium ion solution. Soak the obtained loose body into the prepared mixed solution.
  • the substrate tube may be placed in a rotary lathe such that the substrate tube is rotated at 30 rpm. Through surface adsorption, rare earth co-doped ions permeate into the loose layer.
  • step 2 the loose layer is taken out from the erbium ion solution, dried and vitrified to obtain a glass rod.
  • the erbium ion solution was poured out. Perform initial nitrogen drying of the substrate tube.
  • the pre-dried substrate tube can be passed through chlorine gas and heated to 800 to 1000 °C to further remove the residual hydroxyl ions in the loose layer.
  • the loose layer is heated to 1500°C and sintered into a transparent and compact glass rod.
  • the gas containing P5+ is introduced to perform gas phase compensation to increase the doping concentration of P5+.
  • the dopant elements are finally fixed into the glass rod, forming a non-porous glass layer.
  • step 1 and step 2 Z times, and gradually increase the concentration of the erbium ion solution each time, Z is an integer greater than 1.
  • step three the glass rod is sintered into a solid glass rod.
  • the vitrified glass rod is sintered into a solid glass rod, a process also known as collapsing.
  • step four the solid glass rod is made into an erbium-doped optical fiber.
  • a solid glass rod is drawn into an erbium-doped fiber.
  • Fig. 12 is a schematic diagram of the structure of the erbium-doped optical fiber provided in this application during the preparation process.
  • a base pipe is provided, and the loose body 1 is deposited in the base pipe. Dip the loose body 1 into the erbium ion solution 1 .
  • the soot body 1 is dried and vitrified to obtain a glass rod 1 . After that, repeat steps one and two.
  • the soot 2 is deposited inside the glass rod 1 . Dip the loose body 2 into the erbium ion solution 2 . The concentration of the erbium ion solution 2 is greater than that of the erbium ion solution 1 . The soot 2 is dried and vitrified to obtain a glass rod 2 . Finally, in step three, the glass rod 2 is collapsed to obtain a solid glass rod. In step four, the solid glass rod is made into an erbium-doped optical fiber.
  • the number of sublayers of the core is equal to Z.
  • Z when Z is 2, in the preparation method, Step 1 and Step 2 are performed a total of 2 times.
  • deposition yielded 2 soot layers.
  • the two layers of loose layers respectively correspond to the two sub-layers of the fiber core.
  • Step 1 and Step 2 are executed 4 times in total.
  • a 4-layer soot layer was deposited.
  • the 4 layers of loose layers respectively correspond to the 4 sub-layers of the fiber core.
  • a 4-layer soot layer is deposited during fabrication.
  • the four layers of loose layers were respectively immersed in different concentrations of erbium ion solutions 1.
  • the concentrations of the four times of erbium ion solutions were Y1, Y2, Y3 and Y4mol/L respectively.
  • the difference between Y2 and Y1 is between 0.001mol/L and 0.004mol/L.
  • the difference between Y3 and Y2 is between 0.004mol/L and 0.01mol/L.
  • the difference between Y4 and Y3 is between 0.01mol/L and 0.016mol/L.
  • EDFA 1301 includes pump light source 1304, optical coupler 1303 and erbium-doped optical fiber 1302.
  • Optical coupler 1303 may be WDM.
  • the pump light source 1304 is used to generate pump light.
  • the optical coupler 1303 is used for receiving signal light and pumping light, and coupling the signal light and pumping light into the erbium-doped optical fiber 1302 .
  • Erbium-doped fiber 1302 is used to amplify signal light under the action of pump light.
  • Fig. 14 is a second structural schematic diagram of the optical communication system provided in this application.
  • the optical communication system includes a sending end 1401, a receiving end 1403 and an EDFA 1402.
  • the sending end 1401 is used to transmit signal light to the receiving end 1403 through an optical fiber.
  • Optical fiber is connected with EDFA 1402.
  • EDFA 1402 is used to generate pump light and amplify signal light according to the pump light.
  • the receiving end 1403 is used for receiving the amplified signal light.
  • multiple EDFAs 1402 can be connected in series between the sending end 1401 and the receiving end 1403. Multiple EDFAs 1402 are used to amplify the signal light multiple times.

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Abstract

本申请公开了一种掺铒光纤。掺铒光纤可以应用于放大器、光通信和稀土掺杂光纤制备等领域。掺铒光纤的纤芯由内向外包括第一层和第二层。第一层包括纤芯的中心。第二层为环形，环形的外圈是纤芯的外圈。第一层的铒离子平均掺杂浓度高于第二层的铒离子平均掺杂浓度。在本申请中，通过降低第二层的铒离子掺杂浓度，可以减少ASE，进而降低掺铒光纤的噪声系数，提高通信质量。

Description

掺铒光纤和掺铒光纤的制备方法
本申请要求于2021年5月28日提交中国国家知识产权局、申请号为CN202110592797.9、申请名称为“掺铒光纤和掺铒光纤的制备方法”的中国专利申请的优先权，其全部内容通过引用结合在本申请中。
技术领域
本申请涉及放大器领域、光通信领域和稀土掺杂光纤制备领域，尤其涉及掺铒光纤和掺铒光纤的制备方法。
背景技术
在光通信系统中，使用掺铒光纤放大器(Erbium Doped Fiber Amplifier，EDFA)放大信号光，可以提高信号光的传输距离。具体地，EDFA包括泵浦光源、光耦合器和掺铒光纤。泵浦光源用于产生泵浦光。光耦合器用于将信号光和泵浦光耦合进掺铒光纤。在掺铒光纤中，泵浦光作为信号光的激励源，放大信号光。
其中，掺铒光纤在激励源的作用下，会产生放大自发辐射(Amplified spontaneous emission，ASE)。ASE会提高掺铒光纤的噪声系数，影响通信质量。
发明内容
本申请提供了一种掺铒光纤和掺铒光纤的制备方法。在申请中，通过降低第二层的铒离子掺杂浓度，可以减少ASE，进而降低掺铒光纤的噪声系数，提高通信质量。
本申请第一方面提供了一种掺铒光纤。掺铒光纤的纤芯由内向外包括第一层和第二层。第一层包括纤芯的中心。第二层为环形，环形的外圈是纤芯的外圈。第一层的铒离子平均掺杂浓度高于第二层的铒离子平均掺杂浓度。
在本申请中，通过降低第二层的铒离子掺杂浓度，可以减少ASE，进而降低掺铒光纤的噪声系数，提高通信质量。此时，第一层的铒离子平均掺杂浓度高于第二层的铒离子平均掺杂浓度。
在第一方面的一种可选方式中，掺铒光纤用于L波段。其中，相比于C波段的掺铒光纤，L波段的掺铒光纤的铒离子浓度更高。因此，本申请中的掺铒光纤可以进一步降低噪声系统，提高通信质量。
在第一方面的一种可选方式中，第一层的铒离子平均掺杂浓度高第二层的铒离子平均掺杂浓度百分之M以上，M大于或等于30。其中，当纤芯中的铒离子分布均匀时，以0dBm的信号光作为L波段的掺铒光纤的输入信号，掺铒光纤的噪声系数一般大于6.0dB，例如6.3dB。通过限定M大于或等于30，可以有效的降低掺铒光纤的噪声系数，例如掺铒光纤的噪声系数可以达到5.5dB以下。
在第一方面的一种可选方式中，M的值在30至75.6之间。其中，当不断提高第一层和第二层的铒离子平均浓度的比值时，会降低掺铒光纤对信号光的增益。本申请限定M的 值小于75.6，可以在尽量少降低增益的基础上，降低掺铒光纤的噪声系数。
在第一方面的一种可选方式中，第一层的横截面积在纤芯的横截面积的百分之N以内，N小于或等于50。其中，当第一层的面积过大时，降低噪声系数的效果有限。通过限定N小于或等于50，可以有效的降低掺铒光纤的噪声系数，例如掺铒光纤的噪声系数可以达到5.5dB以下。
在第一方面的一种可选方式中，N的值在20至50之间。其中，当不断降低第一层的面积时，会降低掺铒光纤对信号光的增益。本申请限定降低第一层的面积大于或等于百分之20，可以在尽量少降低增益的基础上，降低掺铒光纤的噪声系数。
在第一方面的一种可选方式中，第一层的铒离子平均掺杂浓度在2742百万分数(parts per million，ppm)至2966ppm之间。第二层的铒离子平均掺杂浓度在1560ppm至2280ppm之间。其中，当纤芯的铒离子平均掺杂浓度过大时，纤芯会产生更多的ASE，从而提高掺铒光纤的噪声系数。当纤芯的铒离子平均掺杂浓度过小时，会降低掺铒光纤的增益。本申请通过限定纤芯的铒离子平均掺杂浓度，可以在尽量少降低增益的基础上，降低掺铒光纤的噪声系数。
在第一方面的一种可选方式中，第一层包括K个子层，K为大于1的整数。第二层包括P个子层，P为大于0的整数。沿纤芯的中心由内向外，K个子层和P个子层的铒离子掺杂浓度逐渐降低。其中，光强在纤芯中的分布为高斯分布。铒离子在纤芯中的分布越贴近高斯分布，则可以更有效的光纤的噪声系数。本申请将纤芯分为K+P个子层。沿纤芯的中心由内向外，K+P个子层的铒离子掺杂浓度逐渐降低，从而使得铒离子在纤芯中的分布贴近高斯分布。因此，本申请可以更有效的降低掺铒光纤的噪声系数。
在第一方面的一种可选方式中，K和P为2。K个子层包括第一子层和第二子层。P个子层包括第三子层和第四子层。其中，纤芯的子层的层数越多，铒离子在纤芯的分布越贴近高斯分布。但是，纤芯的子层的层数越多，纤芯的加工成本越高。本申请限定纤芯的层数为4，可以在尽量降低加工成本的基础上，降低掺铒光纤的噪声系数。
在第一方面的一种可选方式中，第一子层的铒离子掺杂浓度范围在2687ppm至3087ppm之间。第二子层的铒离子掺杂浓度范围在2006ppm至2406ppm之间。第三子层的铒离子掺杂浓度范围在1028ppm至1428ppm之间。第四子层的铒离子掺杂浓度范围在301ppm至701ppm之间。当纤芯的铒离子浓度满足上述条件时，可以有效的降低掺铒光纤的噪声系数，例如掺铒光纤的噪声系数可以达到5.5dB以下。
在第一方面的一种可选方式中，纤芯中心处的铒离子掺杂浓度在1500ppm至4000ppm之间。 r2
在第一方面的一种可选方式中，纤芯的铒离子掺杂浓度满足以下关系：
Figure PCTCN2022080265-appb-000001
其中，A为纤芯的中心处的铒离子掺杂浓度。C(r)为目标点的铒离子掺杂浓度。r为目标点距离纤芯的中心的距离，β为负值的修正因子。
在第一方面的一种可选方式中，纤芯的半径在0.01微米至0.3微米之间。
在第一方面的一种可选方式中，掺铒光纤的由内向外包括纤芯和包层。
本申请第二方面提供了一种掺铒光纤的制备方法。掺铒光纤的制造方法包括以下步骤：
在基管内沉积疏松层，将所述疏松层浸入铒离子溶液。
将所述疏松层从所述铒离子溶液中取出，对所述疏松层进行干燥并玻璃化，得到玻璃棒。
重复Z次前述两个步骤，并逐渐提高每次的铒离子溶液的浓度，Z为大于1的整数。
将所述玻璃棒烧结成实心的玻璃棒。将所述实心的玻璃棒制成掺铒光纤。
在第二方面的一种可选方式中，Z为4。其中，纤芯的子层的层数越多，铒离子在纤芯的分布越贴近高斯分布。但是，纤芯的子层的层数越多，纤芯的加工成本越高。本申请限定纤芯的层数为4，可以在尽量降低加工成本的基础上，降低掺铒光纤的噪声系数。
在第二方面的一种可选方式中，Z次的铒离子溶液的浓度分别为Y1、Y2、Y3和Y4mol/L。其中，Y2和Y1的差值在0.001mol/L至0.004mol/L之间。Y3和Y2的差值在0.004mol/L至0.01mol/L之间。Y4和Y3的差值在0.01mol/L至0.016mol/L之间。
本申请第三方面提供了一种掺铒光纤放大器EDFA。EDFA包括泵浦光源、光耦合器和前述第一方面或第一方面中任意一种可选方式所述的掺铒光纤。其中，泵浦光源用于产生泵浦光。光耦合器用于接收信号光和泵浦光，将信号光和泵浦光耦合进掺铒光纤。掺铒光纤用于在泵浦光的作用下放大信号光。
本申请第四方面提供了一种光通信系统。光通信系统包括发送端、接收端和前述第三方面所述的EDFA。其中，发送端用于通过光纤向接收端传输信号光。光纤与EDFA相连；EDFA用于产生泵浦光，根据泵浦光放大信号光。接收端用于接收放大后的信号光。
附图说明
图1为铒离子在纤芯中的分布示意图；
图2为本申请中提供的铒离子在纤芯中的第一个分布示意图；
图3为本申请中提供的纤芯的第一个结构示意图；
图4为本申请中提供的纤芯的第二个结构示意图；
图5为本申请中提供的纤芯的第三个结构示意图；
图6为本申请中提供的纤芯的第四个结构示意图；
图7为本申请中提供的光通信系统的第一个结构示意图；
图8为掺铒光纤在不同波长上的噪声系数的分布示意图；
图9为本申请中提供的掺铒光纤的噪声系数的第一个分布示意图；
图10为本申请中提供的掺铒光纤的噪声系数的第二个分布示意图；
图11为本申请中提供的铒离子在纤芯中的第二个分布示意图；
图12为本申请中提供的掺铒光纤在制备过程中的结构示意图；
图13为本申请中提供的EDFA的结构示意图；
图14为本申请中提供的光通信系统的第二个结构示意图。
具体实施方式
本申请提供了一种掺铒光纤和掺铒光纤的制备方法。在本申请中，通过降低第二层的铒离子掺杂浓度，可以减少ASE，进而降低掺铒光纤的噪声系数，提高通信质量。应理解，本申请中使用的“第一”、“第二”等仅用于区分描述的目的，而不能理解为指示或暗示相 对重要性，也不能理解为指示或暗示顺序。另外，为了简明和清楚，本申请多个附图中重复参考编号和/或字母。重复并不表明各种实施例和/或配置之间存在严格的限定关系。
本申请中的掺铒光纤用于光通信领域。在光通信领域中，放大器中的掺铒光纤用于在激励源的作用下放大信号光。信号光在掺铒光纤的纤芯中传输。纤芯中铒离子的分布均匀时，放大器会产生较大的噪声系数。具体地，图1为铒离子在纤芯中的分布示意图。如图1所示，横坐标为纤芯的位置，单位为微米μm。在图1中，纤芯的中心位于坐标0处。纤芯的半径为2.5微米，直径为5微米。纵坐标为纤芯的铒离子掺杂浓度，单位为ppm。铒离子在纤芯中均匀分布。因此，浓度101为一条直线。应理解，在实际加工过程中，由于加工工艺不能保证纤芯中每个点的浓度相同。因此，浓度101也可以为一条上下波动的曲线。
在激励源的作用下，纤芯中的铒离子从基态跃迁到上能级。当信号光注入纤芯时，信号光的光强主要分布在纤芯的内层。内层的上能级铒离子产生受激辐射，从而放大信号光。在纤芯的外层中，上能级铒离子无法获得足够的信号光进行受激辐射，自发的从激发态跃迁到基态，产生ASE。ASE是放大器或掺铒光纤的主要噪声来源。具体地，以下为噪声系数NF的计算公式。
Figure PCTCN2022080265-appb-000002
其中，P ASE为放大器或掺铒光纤的噪声功率，噪声功率是由ASE产生的。h为普朗克常数。v为信号光频率。B为光谱仪探测线宽。G为放大器的增益。在放大器的增益不变的情况下，NF与放大器的P ASE强相关。具体地，P ASE越大，NF越大；P ASE越小，NF越小。因此，当纤芯的外层产生大量ASE时，掺铒光纤会产生较大的噪声系数。
为此，本申请提供了一种掺铒光纤。在掺铒光纤的纤芯中，降低外层的铒离子掺杂浓度，进而减少ASE，降低掺铒光纤的噪声系数。此时，纤芯内层的铒离子平均掺杂浓度高于纤芯外层的铒离子平均掺杂浓度。例如，图2为本申请中提供的铒离子在纤芯中的第一个分布示意图。如图2所示，纤芯内层的铒离子平均掺杂浓度为浓度201。纤芯外层的铒离子平均掺杂浓度为浓度202。浓度202小于浓度201。应理解，在实际加工过程中，由于加工工艺不能保证纤芯中每个点的浓度相同。因此，浓度201和浓度201也可以为一条上下波动的曲线。类似的，在后续的描述中，“第一子层内的铒离子掺杂浓度相同”是指“第一子层内的铒离子掺杂浓度大致相同”。
上面对本申请中纤芯的铒离子平均掺杂浓度进行描述，下面对本申请中的纤芯结构进行描述。图3为本申请中提供的纤芯的第一个结构示意图。如图3所示，纤芯包括第一层301和第二层302。第一层301也称为内层，第二层302也称为外层。其中，第一层301可为圆形。第一层301包括纤芯的中心。第二层为环形。环形的外圈是纤芯的外圈。第一层301的铒离子平均掺杂浓度高于第二层302的铒离子平均掺杂浓度。
应理解，当纤芯包括2个子层时，第一层301和第二层302的交界线和2个子层之间的交界线可能重叠，也可能不重叠。
当两个交界线重叠时，交界线处的铒离子掺杂浓度存在突变。具体地，如图3所示，2个子层包括第一子层和第二子层。第一层301即为第一子层，第二层302即为第二子层。第一子层内的铒离子掺杂浓度相同。第二子层内的铒离子掺杂浓度相同。此时，由于第一子层内的铒离子掺杂浓度大于第二子层内的铒离子掺杂浓度，交界线处的铒离子掺杂浓度 存在突变。
当两个交界线不重叠时，2个子层的交界线处的铒离子掺杂浓度存在突变。第一层301和第二层302的交界线处的铒离子掺杂浓度不存在突变。具体地，图4为本申请中提供的纤芯的第二个结构示意图。如图4所示，纤芯包括第一交界线401和第二交界线402。第一交界线401将纤芯分为第一子层和第二子层。第一子层在第一交界线401以内，第一子层内的铒离子掺杂浓度相同。第二子层在第二交界线401以外，第二子层内的铒离子掺杂浓度相同。第一子层的铒离子掺杂浓度高于第二子层的铒离子掺杂浓度。因此，在第一交界线401处，铒离子掺杂浓度存在突变。第二交界线402将纤芯分为第一层和第二层。第一层在第二交界线402以内，第二层在第二交界线402以外。第一层的铒离子平均掺杂浓度高于第二层的铒离子平均掺杂浓度。但是，由于第一子层内的铒离子掺杂浓度相同，第二交界线402处于第一子层内，第二交界线402处的铒离子掺杂浓度不存在突变。
在其它实施例中，纤芯中所有的层交界线和子层交界线重叠。层交界线为“层”与“层”之间的交界线，子层交界线为“子层”与“子层”之间的交界线。
在申请的附图中，实线表示铒离子掺杂浓度存在突变的交界线或分界线，实线两侧属于不同的“子层”。关于“子层”的定义，还可以参阅后续掺铒光纤的制备方法中对子层的描述。虚线两侧属于不同的“层”。
图5为本申请中提供的纤芯的第三个结构示意图。如图5所示，纤芯包括第一层301和第二层302。第一层301包括纤芯的中心。第二层302的外圈是纤芯的外圈。第一层301的铒离子平均掺杂浓度高于第二层302的铒离子平均掺杂浓度。
在其它实施例中，纤芯在第一层和第二层之间还包括其它层。例如，如图5所示，纤芯还包括第三层501。第三层501在第一层301和第二层302之间。第三层501的铒离子平均掺杂浓度小于第一层301的铒离子平均掺杂浓度，第二层302的铒离子平均掺杂浓度小于第三层501的铒离子平均掺杂浓度。
应理解，在本申请的纤芯中，“层”可以包括一个或多个“子层”。例如，第一层包括K个子层，K为大于0的整数。在一种实例中，K为大于1的整数。第二层包括P个子层，P为大于0的整数。其中，光强在纤芯中的分布为高斯分布。铒离子在纤芯中的分布越贴近高斯分布，则可以更有效的降低掺铒光纤的噪声系数。因此，本申请可以限定沿纤芯的中心由内向外，K+P个子层的铒离子掺杂浓度逐渐降低，使得铒离子在纤芯中的分布贴近高斯分布。
纤芯的子层的层数越多，可以使得铒离子在纤芯的分布越贴近高斯分布。但是，纤芯的子层的层数越多，纤芯的加工成本越高。本申请可以限定K和P为2，在尽量降低加工成本的基础上，降低掺铒光纤的噪声系数。此时，K个子层包括第一子层和第二子层。P个子层包括第三子层和第四子层。具体地，图6为本申请中提供的纤芯的第四个结构示意图。如图6所示，纤芯包括第一子层601、第二子层602、第三子层603和第四子层604。其中，第一子层601和第二子层602属于第一层。第三子层603和第四子层604属于第二层。沿纤芯的中心由内向外，第一子层601、第二子层602、第三子层603和第四子层604的铒离子掺杂浓度逐渐降低。
在其它的实施例中，本申请的掺铒光纤用于L波段。具体地，L波断的信号光在掺铒 光纤中的增益系数较低。因此，为了提高掺铒光纤放大器的增益，需要提高掺铒光纤的铒离子掺杂浓度。例如，当掺铒光纤用于C波段时，掺铒光纤的铒离子掺杂浓度一般为300ppm至500ppm。当掺铒光纤用于L波段时，掺铒光纤的铒离子掺杂浓度一般需要大于1500ppm。在提高掺铒光纤的铒离子掺杂浓度后，掺铒光纤的外层拥有更多的铒离子。更多的铒离子产生更大的ASE，进而产生更大的噪声系数。例如，C波段的掺铒光纤放大器的噪声系数一般小于5dB。L波段的掺铒光纤放大器的噪声系数一般大于6dB。因此，在L波段时，更需要降低掺铒光纤外层的铒离子掺杂浓度，降低噪声系数。
根据前面的描述可知，当纤芯中铒离子的分布均匀时，放大器会产生较大的噪声系数。下面以一个具体的实验场景进行描述。图7为本申请中提供的光通信系统的第一个结构示意图。如图7所示，光通信系统包括光放大器701、光放大器705、光放大器709和光谱分析仪(optical spectrum analyzers，OSA)713。光放大器701包括泵浦光源704、波分复用器(Wavelength Division Multiplexing，WDM)703和掺铒光纤702。泵浦光源704用于产生泵浦光。WDM 703用于将信号光和泵浦光耦合进掺铒光纤702。在掺铒光纤702中，泵浦光作为信号光的激励源，放大信号光。类似地，光放大器705包括泵浦光源708、波分复用器WDM 707和掺铒光纤706。光放大器709包括泵浦光源712、波分复用器WDM 711和掺铒光纤710。在图7的光通信系统中，实现了对信号光的三级放大。OSA 713用于测量三级放大后的信号光噪声系数。当掺铒光纤702、掺铒光纤706和掺铒光纤710中的铒离子分布均匀时，以0dBm的L波段的信号光作为输入信号，测量放大器的噪声系数。放大器的噪声系数也可以称为掺铒光纤的噪声系数。图8为掺铒光纤在不同波长上的噪声系数的分布示意图。如图8所示，横坐标为波长，单位为纳米nm。纵坐标为噪声系数，单位为dB。在1575nm至1618nm范围内，放大器的噪声系数最大值为6.6dB，平均噪声系数大约为6.3dB。
采用图7中的光通信系统测量本申请中掺铒光纤放大器的噪声系数。掺铒光纤的结构示意图如图3所示。
在实验一中，第一层301的面积占纤芯面积的50％。第一层301的铒离子平均掺杂浓度为2742ppm。第二层302铒离子平均掺杂浓度为1560ppm。第一层301的铒离子平均掺杂浓度高第二层302的铒离子平均掺杂浓度75.6％。图9为本申请中提供的掺铒光纤的噪声系数的第一个分布示意图。如图9所示，在1575nm至1618nm范围内，掺铒光纤放大器的噪声系数最大值为5.2dB，平均噪声系数小于5dB。
在实验二中，第一层301的面积占纤芯面积的20％。第一层301的铒离子平均掺杂浓度为2966ppm。第二层302铒离子平均掺杂浓度为2280ppm。第一层301的铒离子平均掺杂浓度高第二层302的铒离子平均掺杂浓度30％。图10为本申请中提供的掺铒光纤的噪声系数的第二个分布示意图。如图10所示，在1575nm至1618nm范围内，掺铒光纤放大器的噪声系数最大值为5.4dB，平均噪声系数小于5.2dB。
定义第一层的铒离子平均掺杂浓度高第二层的铒离子平均掺杂浓度百分之M以上。通过上述实验可知，当M的值在30至75.6之间时，掺铒光纤放大器的平均噪声系数小于5.5dB。定义第一层的横截面积在纤芯的横截面积的百分之N以内。通过上述实验可知，当N的值在20至50之间时，掺铒光纤放大器的平均噪声系数小于5.5dB。通过上述实验可知，当第 一层的铒离子平均掺杂浓度在2742ppm至2966ppm之间，第二层的铒离子平均掺杂浓度在1560ppm至2280ppm之间时，掺铒光纤放大器的平均噪声系数小于5.5dB。
当采用图6中的纤芯，测量掺铒光纤放大器的噪声系数时，可以得到类似图9中的实验结果。此时，第一子层601的面积占纤芯面积的19％，第一子层601的铒离子掺杂浓度为2887ppm。第二子层602的面积占纤芯面积的26％，第二子层602的铒离子掺杂浓度为2206ppm。第三子层603的面积占纤芯面积的27％，第三子层603的铒离子掺杂浓度为1228ppm。第四子层604的面积占纤芯面积的28％，第四子层604的铒离子掺杂浓度为501ppm。由于纤芯加工过程中可能会存在误差，将误差定义为正负200ppm。此时，第一子层601的铒离子掺杂浓度范围在2687ppm至3087ppm之间。第二子层602的铒离子掺杂浓度范围在2006ppm至2406ppm之间。第三子层603的铒离子掺杂浓度范围在1028ppm至1428ppm之间。第四子层604的铒离子掺杂浓度范围在301ppm至701ppm之间。
在其它实施例中，通过增加纤芯中子层的层数，实现铒离子在纤芯中的分布为高斯分布。具体的，纤芯的铒离子掺杂浓度满足以下关系。
Figure PCTCN2022080265-appb-000003
其中，A为纤芯的中心处的铒离子掺杂浓度。A的范围在1500ppm至4000ppm之间。C(r)为目标点的铒离子掺杂浓度。r为目标点距离纤芯的中心的距离。r小于或等于R。R为纤芯的半径。R的范围在0.01微米至0.3微米之间。β为负值的修正因子。具体地，图11为本申请中提供的铒离子在纤芯中的第二个分布示意图。如图11所示，在R等于2.5，A等于3000，β等于负0.5时，铒离子在纤芯中的分布趋近于高斯分布。
上面对本申请中的掺铒光纤进行描述。下面对本申请中的掺铒光纤的制备方法进行描述。掺铒光纤的制备方法包括以下步骤。
在步骤一中，在基管内沉积疏松层，将疏松层浸入铒离子溶液。
首先对基管进行预处理，使基管预热和有效消除基管内壁的杂质和气泡。然后通过MCVD设备向基管通入原材料。在热源氢氧喷灯的加热条件下使原材料发生化学反应，生成二氧化硅、五氧化二磷、氟氧化硅、三氧化二硼等细微颗粒。在热泳效应及管内气体的带动下，细微颗粒沉积附着在基管的内表面。在较低加热温度下(例如1300℃～1500℃)会形成白色不透明的多孔的疏松层，形成长度在150mm至300mm之间的多孔的疏松层。
在超净环境中，将稀土共掺原料按照特定比例溶解到酒精或者盐酸的溶液中，得到混合溶液。在混合溶液中，包括铒离子Er3+、磷离子P5+、铝离子Al3+、镧La3+等离子。因此，混合溶液也称为铒离子溶液。将得到的疏松体泡入配制好的混合溶液中。在浸泡的过程中，可以将基管置于旋转车床中，使得基管进行30转/分钟的旋转。通过表面吸附作用，稀土共掺离子渗透进疏松层。
在步骤二中，将疏松层从铒离子溶液中取出，对疏松层进行干燥并玻璃化，得到玻璃棒。
在浸泡2个小时后，将铒离子溶液倒出。对基管进行初步氮气干燥。为了降低掺铒光纤的背景损耗，可以将初步干燥好的基管通入氯气并加热到800至1000℃，进一步除去疏松层里面残留的羟基离子。干燥完成后，将疏松层加热到1500℃烧结成透明密实的玻璃棒。再通入含P5+的气体进行气相补偿提高P5+的掺杂浓度。将掺杂元素最终固定到玻璃棒中， 形成无孔的玻璃层。
重复Z次步骤一和步骤二，并逐渐提高每次的铒离子溶液的浓度，Z为大于1的整数。
在步骤三中，将玻璃棒烧结成实心的玻璃棒。
在高温下，将玻璃化后的玻璃棒烧结成实心的玻璃棒，这个过程也称为塌缩。
在步骤四中，将实心的玻璃棒制成掺铒光纤。将实心的玻璃棒拉细成掺铒光纤。
在本申请中掺铒光纤的制备方法中，Z是大于0的整数。下面以Z为2为例，最本申请中掺铒光纤的制备方法进行描述。图12为本申请中提供的掺铒光纤在制备过程中的结构示意图。如图12所示，首先，在步骤一中，提供基管，在基管内沉积疏松体1。将疏松体1浸入铒离子溶液1。然后，在步骤二中，对疏松体1进行干燥并玻璃化，得到玻璃棒1。之后，重复步骤一和步骤二。具体地，在玻璃棒1内沉积疏松体2。将疏松体2浸入铒离子溶液2。铒离子溶液2的浓度大于铒离子溶液1的浓度。对疏松体2进行干燥并玻璃化，得到玻璃棒2。最后，在步骤三中，对玻璃棒2进行塌缩，得到实心的玻璃棒。在步骤四中，将实心的玻璃棒制成掺铒光纤。
在通过本申请中制备方法得到的掺杂光纤中，纤芯的子层的层数等于Z。例如，当Z为2时，在制备方法中，总共执行了2次步骤一和步骤二。在制备过程中，沉积得到了2层的疏松层。2层的疏松层分别对应纤芯的2个子层。例如，当Z为4时，在制备方法中，总共执行了4次步骤一和步骤二。在制备过程中，沉积得到了4层的疏松层。4层的疏松层分别对应纤芯的4个子层。
当Z等于4时，在制备过程中，沉积得到了4层的疏松层。4层的疏松层分别浸入不同浓度的铒离子溶液1。4次的铒离子溶液的浓度分别为Y1、Y2、Y3和Y4mol/L。其中，Y2和Y1的差值在0.001mol/L至0.004mol/L之间。Y3和Y2的差值在0.004mol/L至0.01mol/L之间。Y4和Y3的差值在0.01mol/L至0.016mol/L之间。通过逐渐提高每次的铒离子溶液的浓度，可以使得纤芯外层的铒离子平均掺杂浓度低于纤芯内层的铒离子平均掺杂浓度。
上面对本申请中的掺铒光纤的制备方法进行描述，下面对本申请中提供的EDFA进行描述。图13为本申请中提供的EDFA的结构示意图。如图13所示，EDFA 1301包括泵浦光源1304、光耦合器1303和掺铒光纤1302。光耦合器1303可以是WDM。泵浦光源1304用于产生泵浦光。光耦合器1303用于接收信号光和泵浦光，将信号光和泵浦光耦合进掺铒光纤1302。掺铒光纤1302用于在泵浦光的作用下放大信号光。关于掺铒光纤的描述，可以参考前述对掺铒光纤以及掺铒光驱的制备方法中的描述。
上面对本申请中的EDFA进行描述，下面对本申请中提供的光通信系统进行描述。图14为本申请中提供的光通信系统的第二个结构示意图。如图14所示，光通信系统包括发送端1401、接收端1403和EDFA 1402。其中，发送端1401用于通过光纤向接收端1403传输信号光。光纤与EDFA 1402相连。EDFA 1402用于产生泵浦光，根据泵浦光放大信号光。接收端1403用于接收放大后的信号光。关于EDFA 1402的描述可以参考前述EDFA 1301的描述。
在其它实施例中，发送端1401和接收端1403之间可以串联多个EDFA 1402。多个EDFA 1402用于对信号光进行多次放大。
以上，仅为本申请的具体实施方式，但本申请的保护范围并不局限于此，任何熟悉本技术领域的技术人员在本申请揭露的技术范围内，可轻易想到变化或替换，都应涵盖在本申请的保护范围之内。

Claims (18)

  1. 一种掺铒光纤，其特征在于，所述掺铒光纤的纤芯由内向外包括第一层和第二层，所述第一层包括所述纤芯的中心，所述第二层为环形，所述环形的外圈是所述纤芯的外圈，其中，所述第一层的铒离子平均掺杂浓度高于所述第二层的铒离子平均掺杂浓度。
  2. 根据权利要求1所述的掺铒光纤，其特征在于，所述掺铒光纤用于L波段。
  3. 根据权利要求1或2所述的掺铒光纤，其特征在于，所述第一层的铒离子平均掺杂浓度高所述第二层的铒离子平均掺杂浓度百分之M以上，M大于或等于30。
  4. 根据权利要求3所述的掺铒光纤，其特征在于，所述M的值在30至75.6之间。
  5. 根据权利要求1至4中任意一项所述的掺铒光纤，其特征在于，所述第一层的铒离子平均掺杂浓度在2742百万分数ppm至2966ppm之间，所述第二层的铒离子平均掺杂浓度在1560ppm至2280ppm之间。
  6. 根据权利要求1至5中任意一项所述的掺铒光纤，其特征在于，所述第一层的横截面积在所述纤芯的横截面积的百分之N以内，N小于或等于50。
  7. 根据权利要求6所述的掺铒光纤，其特征在于，所述N的值在20至50之间。
  8. 根据权利要求1至7中任意一项所述的掺铒光纤，其特征在于，所述第一层包括K个子层，K为大于1的整数，所述第二层包括P个子层，P为大于0的整数；
    其中，沿所述纤芯的中心由内向外，所述K个子层和所述P个子层的铒离子掺杂浓度逐渐降低。
  9. 根据权利要求8所述的掺铒光纤，其特征在于，所述K和所述P为2，所述K个子层包括第一子层和第二子层，所述P个子层包括第三子层和第四子层，所述第一子层的铒离子掺杂浓度范围在2687ppm至3087ppm之间，所述第二子层的铒离子掺杂浓度范围在2006ppm至2406ppm之间，所述第三子层的铒离子掺杂浓度范围在1028ppm至1428ppm之间，所述第四子层的铒离子掺杂浓度范围在301ppm至701ppm之间。
  10. 根据权利要求1至9中任意一项所述的掺铒光纤，其特征在于，所述纤芯中心处的铒离子掺杂浓度在1500ppm至4000ppm之间。
  11. 根据权利要求1至10中任意一项所述的掺铒光纤，其特征在于，所述纤芯的铒离子掺杂浓度满足以下关系：
    Figure PCTCN2022080265-appb-100001
    其中，A为所述纤芯的中心处的铒离子掺杂浓度，C(r)为目标点的铒离子掺杂浓度，r为所述目标点距离所述纤芯的中心的距离，β为负值的修正因子。
  12. 根据权利要求1至11中任意一项所述的掺铒光纤，其特征在于，所述纤芯的半径在0.01微米至0.3微米之间。
  13. 根据权利要求1至12中任意一项所述的掺铒光纤，其特征在于，所述掺铒光纤的由内向外包括所述纤芯和包层。
  14. 一种掺铒光纤的制备方法，其特征在于，包括：
    在基管内沉积疏松层，将所述疏松层浸入铒离子溶液；
    将所述疏松层从所述铒离子溶液中取出，对所述疏松层进行干燥并玻璃化，得到玻璃棒；
    重复Z次上述两个步骤，并逐渐提高每次的铒离子溶液的浓度，Z为大于1的整数；
    将所述玻璃棒烧结成实心的玻璃棒；
    将所述实心的玻璃棒制成掺铒光纤。
  15. 根据权利要求14所述的制备方法，其特征在于，所述Z为4。
  16. 根据权利要求15所述的制备方法，其特征在于，Z次的铒离子溶液的浓度分别为Y1、Y2、Y3和Y4mol/L；
    其中，Y2和Y1的差值在0.001mol/L至0.004mol/L之间，Y3和Y2的差值在0.004mol/L至0.01mol/L之间，Y4和Y3的差值在0.01mol/L至0.016mol/L之间。
  17. 一种掺铒光纤放大器，其特征在于，包括：泵浦光源、光耦合器和前述权利要求1至13中任意一项所述的掺铒光纤；
    所述泵浦光源用于产生泵浦光；
    所述光耦合器用于接收信号光和所述泵浦光，将所述信号光和所述泵浦光耦合进所述掺铒光纤；
    所述掺铒光纤用于在所述泵浦光的作用下放大所述信号光。
  18. 一种光通信系统，其特征在于，包括：
    发送端、接收端和前述权利要求17所述的掺铒光纤放大器EDFA；
    其中，所述发送端用于通过光纤向所述接收端传输信号光；
    所述光纤与所述EDFA相连；
    所述EDFA用于产生泵浦光，根据所述泵浦光放大所述信号光；
    所述接收端用于接收放大后的所述信号光。
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Citations (7)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP2012162433A (ja) * 2011-02-09 2012-08-30 Mitsubishi Cable Ind Ltd 希土類添加光ファイバ及びその製造方法
CN103257394A (zh) * 2013-04-26 2013-08-21 中国人民解放军国防科学技术大学 用于输出特定单一模式激光的增益光纤
CN103728691A (zh) * 2013-12-26 2014-04-16 长春理工大学 阶跃高斯复合型掺杂离子浓度分布增益光纤
CN105207046A (zh) * 2015-10-22 2015-12-30 南京大学（苏州）高新技术研究院 一种提高掺铒光纤放大器抗辐射能力的方法
CN105244741A (zh) * 2015-11-05 2016-01-13 长飞光纤光缆股份有限公司 一种大模场掺镱光纤
CN108802898A (zh) * 2018-08-29 2018-11-13 法尔胜泓昇集团有限公司 一种大模场掺镱有源光纤及其制备方法
CN112510472A (zh) * 2019-09-16 2021-03-16 华为技术有限公司 一种少模掺铒光纤以及少模掺铒光纤放大器

Family Cites Families (10)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US5027079A (en) * 1990-01-19 1991-06-25 At&T Bell Laboratories Erbium-doped fiber amplifier
GB9010943D0 (en) * 1990-05-16 1990-07-04 British Telecomm Wave-guiding structure with lasing properties
JP3369158B2 (ja) * 1999-05-28 2003-01-20 住友電気工業株式会社 光増幅用光ファイバ及び光ファイバ増幅器
US20030145629A1 (en) * 2001-12-31 2003-08-07 3M Innovative Properties Company Method of manufacturing improved emission silicate waveguide compositions for enhanced L-band and S-band emission
US7164833B2 (en) * 2003-09-24 2007-01-16 Fitel U.S.A. Corp. Optical fiber for improved performance in S-, C- and L-bands
US8767286B2 (en) * 2010-04-12 2014-07-01 Lockheed Martin Corporation Signal and pump mode-field adaptor for double-clad fibers and associated method
CN102086089A (zh) * 2010-12-27 2011-06-08 富通集团有限公司 一种制造掺稀土光纤预制棒的方法
US9007681B2 (en) * 2011-12-13 2015-04-14 Ofs Fitel, Llc Multi-core erbium-doped fiber amplifier
CN104591535B (zh) * 2014-11-04 2017-11-14 华南师范大学 采用激光熔炼技术制备稀土掺杂石英玻璃微结构光纤的方法
CN115735305A (zh) * 2020-08-17 2023-03-03 古河电气工业株式会社 光放大光纤、光纤放大器以及光通信系统

Patent Citations (7)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP2012162433A (ja) * 2011-02-09 2012-08-30 Mitsubishi Cable Ind Ltd 希土類添加光ファイバ及びその製造方法
CN103257394A (zh) * 2013-04-26 2013-08-21 中国人民解放军国防科学技术大学 用于输出特定单一模式激光的增益光纤
CN103728691A (zh) * 2013-12-26 2014-04-16 长春理工大学 阶跃高斯复合型掺杂离子浓度分布增益光纤
CN105207046A (zh) * 2015-10-22 2015-12-30 南京大学（苏州）高新技术研究院 一种提高掺铒光纤放大器抗辐射能力的方法
CN105244741A (zh) * 2015-11-05 2016-01-13 长飞光纤光缆股份有限公司 一种大模场掺镱光纤
CN108802898A (zh) * 2018-08-29 2018-11-13 法尔胜泓昇集团有限公司 一种大模场掺镱有源光纤及其制备方法
CN112510472A (zh) * 2019-09-16 2021-03-16 华为技术有限公司 一种少模掺铒光纤以及少模掺铒光纤放大器

Non-Patent Citations (1)

* Cited by examiner, † Cited by third party
Title
See also references of EP4336680A4

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