CN115047561A - Erbium-ytterbium co-doped double-clad double-ring-shaped few-mode gain optical fiber - Google Patents
Erbium-ytterbium co-doped double-clad double-ring-shaped few-mode gain optical fiber Download PDFInfo
- Publication number
- CN115047561A CN115047561A CN202210707185.4A CN202210707185A CN115047561A CN 115047561 A CN115047561 A CN 115047561A CN 202210707185 A CN202210707185 A CN 202210707185A CN 115047561 A CN115047561 A CN 115047561A
- Authority
- CN
- China
- Prior art keywords
- double
- ring
- doped
- fiber
- few
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Granted
Links
- KWMNWMQPPKKDII-UHFFFAOYSA-N erbium ytterbium Chemical compound [Er].[Yb] KWMNWMQPPKKDII-UHFFFAOYSA-N 0.000 title claims abstract description 28
- 239000013307 optical fiber Substances 0.000 title claims description 28
- 239000000835 fiber Substances 0.000 claims abstract description 91
- 238000005253 cladding Methods 0.000 claims abstract description 79
- -1 rare earth ions Chemical class 0.000 claims abstract description 41
- 229910052691 Erbium Inorganic materials 0.000 claims abstract description 17
- 229910052761 rare earth metal Inorganic materials 0.000 claims abstract description 14
- 229910052769 Ytterbium Inorganic materials 0.000 claims abstract description 10
- 150000002500 ions Chemical class 0.000 claims abstract description 10
- 239000000463 material Substances 0.000 claims abstract description 6
- 239000010453 quartz Substances 0.000 claims abstract description 6
- VYPSYNLAJGMNEJ-UHFFFAOYSA-N silicon dioxide Inorganic materials O=[Si]=O VYPSYNLAJGMNEJ-UHFFFAOYSA-N 0.000 claims abstract description 6
- 230000001788 irregular Effects 0.000 claims abstract description 4
- 230000005540 biological transmission Effects 0.000 claims description 15
- 238000005086 pumping Methods 0.000 claims description 13
- 238000001514 detection method Methods 0.000 claims description 3
- 238000001228 spectrum Methods 0.000 claims description 3
- 239000000126 substance Substances 0.000 claims description 2
- 230000003287 optical effect Effects 0.000 description 10
- 238000000034 method Methods 0.000 description 6
- 230000003321 amplification Effects 0.000 description 4
- 238000010586 diagram Methods 0.000 description 4
- 238000003199 nucleic acid amplification method Methods 0.000 description 4
- 238000004891 communication Methods 0.000 description 3
- 238000005516 engineering process Methods 0.000 description 3
- 230000010287 polarization Effects 0.000 description 3
- 230000001276 controlling effect Effects 0.000 description 2
- 230000007547 defect Effects 0.000 description 2
- 239000002019 doping agent Substances 0.000 description 2
- 230000001105 regulatory effect Effects 0.000 description 2
- 101710121003 Oxygen-evolving enhancer protein 3, chloroplastic Proteins 0.000 description 1
- 230000009286 beneficial effect Effects 0.000 description 1
- 238000013461 design Methods 0.000 description 1
- 238000011161 development Methods 0.000 description 1
- 230000000694 effects Effects 0.000 description 1
- 230000002349 favourable effect Effects 0.000 description 1
- 238000012986 modification Methods 0.000 description 1
- 230000004048 modification Effects 0.000 description 1
- 230000008054 signal transmission Effects 0.000 description 1
- 238000006467 substitution reaction Methods 0.000 description 1
Images
Classifications
-
- G—PHYSICS
- G02—OPTICS
- G02B—OPTICAL ELEMENTS, SYSTEMS OR APPARATUS
- G02B6/00—Light guides; Structural details of arrangements comprising light guides and other optical elements, e.g. couplings
- G02B6/02—Optical fibres with cladding with or without a coating
- G02B6/036—Optical fibres with cladding with or without a coating core or cladding comprising multiple layers
- G02B6/03616—Optical fibres characterised both by the number of different refractive index layers around the central core segment, i.e. around the innermost high index core layer, and their relative refractive index difference
- G02B6/03622—Optical fibres characterised both by the number of different refractive index layers around the central core segment, i.e. around the innermost high index core layer, and their relative refractive index difference having 2 layers only
- G02B6/03627—Optical fibres characterised both by the number of different refractive index layers around the central core segment, i.e. around the innermost high index core layer, and their relative refractive index difference having 2 layers only arranged - +
-
- G—PHYSICS
- G02—OPTICS
- G02F—OPTICAL DEVICES OR ARRANGEMENTS FOR THE CONTROL OF LIGHT BY MODIFICATION OF THE OPTICAL PROPERTIES OF THE MEDIA OF THE ELEMENTS INVOLVED THEREIN; NON-LINEAR OPTICS; FREQUENCY-CHANGING OF LIGHT; OPTICAL LOGIC ELEMENTS; OPTICAL ANALOGUE/DIGITAL CONVERTERS
- G02F1/00—Devices or arrangements for the control of the intensity, colour, phase, polarisation or direction of light arriving from an independent light source, e.g. switching, gating or modulating; Non-linear optics
- G02F1/35—Non-linear optics
- G02F1/39—Non-linear optics for parametric generation or amplification of light, infrared or ultraviolet waves
-
- 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
-
- 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
Landscapes
- Physics & Mathematics (AREA)
- Electromagnetism (AREA)
- Optics & Photonics (AREA)
- Engineering & Computer Science (AREA)
- Plasma & Fusion (AREA)
- Nonlinear Science (AREA)
- General Physics & Mathematics (AREA)
- Lasers (AREA)
Abstract
The invention discloses an erbium-ytterbium co-doped double-clad double-annular few-mode gain fiber, which belongs to the technical field of mode division multiplexing and is characterized by comprising the following components from inside to outside: the fiber core, the inner ring, the inner cladding and the outer cladding, wherein the outer ring is arranged in the middle of the inner cladding; the cross sections of the fiber core, the inner ring, the outer ring and the outer cladding are all circular; the cross section of the inner cladding is an irregular polygon; the fiber core is made of quartz material doped with ions; the inner ring and the outer ring are doped with rare earth ions, and the rare earth ions comprise erbium ions and ytterbium ions; the refractive index is gradually reduced from the fiber core to the junction with the inner cladding, and is kept unchanged in the inner cladding, and the refractive index of the outer cladding is lower than that of the inner cladding. According to the invention, on one hand, the doping content of erbium ions is improved by introducing ytterbium ions so as to improve the gain of each mode, and on the other hand, the tail part of an evanescent field of a signal mode is utilized by adding an outer ring into an inner cladding layer so as to further improve the gain.
Description
Technical Field
The invention belongs to the technical field of mode division multiplexing, and particularly relates to an erbium-ytterbium co-doped double-clad double-ring few-mode gain fiber.
Background
With the development of big data, cloud services and the internet of things, the capacity demand of people on the existing communication network is exponentially increased. However, the transmission capacity of existing single-mode optical fiber communication systems has approached the shannon limit, and therefore, it is becoming urgent to develop new information transmission dimensions to meet the increasing capacity demand. In other multiplexing dimensions of single mode fibers such as: on the basis of full utilization of time division multiplexing, polarization multiplexing, orthogonal frequency division multiplexing, wavelength division multiplexing, and the like, space division multiplexing has attracted much attention and has been rapidly developed in large-capacity optical fiber communication systems.
The space division multiplexing technology comprises core division multiplexing and mode division multiplexing, wherein the core division multiplexing refers to the transmission of signals by using each fiber core of the multi-core optical fiber as an independent transmission channel; the mode division multiplexing technology is to transmit a small number of spatial modes by using few-mode optical fibers, load signals of different channels on each mode, and transmit the signals by using the orthogonality of the modes. The space division multiplexing transmission system based on few-mode optical fibers can realize simultaneous transmission of a plurality of channels, so that the transmission capacity is multiplied. The space division multiplexing technology adopting few-mode optical fiber as a transmission line is to realize long-distance transmission, and the few-mode erbium-doped optical fiber amplifier is a key device for compensating the transmission loss of a few-mode transmission system. However, in the process of optical amplification, the overlapping of each signal mode optical field, the pump optical field, and the erbium ion distribution on the cross section of the optical fiber is inconsistent, so that the gains obtained by amplifying different modes in the few-mode optical fiber are different, and the transmission is limited due to high differential mode gain, so that it is important to minimize the differential mode gain in the few-mode erbium-doped optical fiber amplifier.
The existing methods for reducing the differential mode gain of the erbium-doped fiber amplifier mainly comprise two methods: (1) and regulating and controlling the pump mode ratio. The mode of pumping is changed, the power ratio is adjusted to reduce the difference of the overlapping factors of the optical field of each signal mode, the pumped optical field and erbium ion distribution, and the gain balance among the modes is realized. (2) And designing the doping ion distribution and the refractive index profile of the few-mode gain fiber. The difference of overlapping factors among modes is reduced by designing the erbium ion distribution and the erbium ion concentration of the few-mode erbium-doped fiber; by designing the refractive index profile, the mode field distribution of various modes of the optical fiber can be adjusted, the overlapping integral factor of the signal light and the pump light is increased, and the gain balance among the modes is realized. The mode balances the gains among the modes by designing the optical fiber with a special structure, and has better effect.
Disclosure of Invention
Aiming at the defects or improvement requirements in the prior art, the invention provides an erbium-ytterbium co-doped double-clad double-ring few-mode gain fiber, aiming at effectively reducing the difference of overlapping factors of each mode by designing a ring-shaped doped fiber and solving the technical problem that the prior art can not reduce the differential mode gain while ensuring the gain of a few-mode erbium-doped fiber amplifier.
To achieve the above object, according to one aspect of the present invention, there is provided an erbium ytterbium co-doped double-clad double-ring type few-mode gain optical fiber, comprising from the inside out: the fiber core comprises a fiber core 1-2, an inner ring 1-1, an inner cladding 1-4 and an outer cladding 1-5, wherein an outer ring 1-3 is arranged in the middle of the inner cladding 1-4; wherein the content of the first and second substances,
the cross sections of the fiber core 1-2, the inner ring 1-1, the outer ring 1-3 and the outer cladding 1-5 are all circular; the cross section of the inner cladding layers 1-4 is an irregular polygon;
the fiber core 1-2 is made of quartz material doped with ions; the inner ring 1-1 and the outer ring 1-3 are doped with rare earth ions, and the rare earth ions comprise erbium ions and ytterbium ions;
the refractive index is gradually reduced from the fiber core 1-2 to the junction with the inner cladding 1-4, and is kept constant in the inner cladding 1-4, and the refractive index of the outer cladding 1-5 is lower than that of the inner cladding 1-4.
In one embodiment, the inner cladding 1-4 has a cross-section that is "D" shaped, eccentric circular or "plum blossom" shaped.
In one embodiment, the inner diameter of the outer ring 1-3 is greater than or equal to the outer diameter of the inner ring 1-1; the outer diameter of the outer ring 1-3 is smaller than or equal to the radius of the corresponding inscribed circle of the inner cladding 1-4; the width of the outer rings 1-3 can be adjusted.
In one embodiment, the core 1-2 has a diameter of less than 20 microns.
In one embodiment, the inner diameter of the inner ring 1-1 is 0.48 times the radius of the core 1-2, and the diameter of the inner cladding 1-4 is about 125 microns.
In one embodiment, when the few-mode gain fiber is used as a gain medium, it is cladding pumped by a multimode pump light source.
In one embodiment, the pumping mode adopts forward pumping or backward pumping.
According to another aspect of the present invention, there is provided a few-mode erbium-doped fiber amplifier, comprising:
signal light providing means for providing signal light;
a multimode pump light source for emitting pump light;
the beam combiner is used for combining the signal light and the pump light to obtain coupled light;
the few-mode gain optical fiber is arranged on an emergent light path of the coupled light and is used for amplifying the coupled light to obtain amplified light;
and the spectrum detection device is arranged on the transmission light path of the amplified light and is used for collecting the light spots of the amplified light and measuring the power of the amplified light.
In general, compared with the prior art, the above technical solution contemplated by the present invention can achieve the following beneficial effects:
(1) the defect that the gain balance of the existing few-mode optical fiber is difficult to realize under the condition of realizing simultaneous amplification of a plurality of modes can be solved: in the process of carrying out optical amplification on the few-mode erbium-doped fiber amplifier, the overlapping of each signal mode optical field, the pumping optical field and erbium ion distribution on the cross section of the fiber is inconsistent, so that the gains obtained by amplifying different modes in the few-mode fiber are different, and the transmission is limited due to high differential mode gain. The existing methods for reducing the differential mode gain of the erbium-doped fiber amplifier mainly comprise two methods: firstly, the doping ion distribution and the refractive index profile of the few-mode gain fiber are designed by regulating and controlling the pump mode ratio. According to the invention, by designing the annular doped fiber, the problem of large difference of overlapping factors of each mode can be effectively reduced, and the gain can be balanced to a certain degree.
(2) The ring-doped fiber can reduce the differential mode gain to a certain extent, but because the ring-doped fiber is only doped in the ring-shaped region, the rare earth ion content of the gain fiber is greatly reduced, so that the gain of the few-mode erbium-doped fiber amplifier is reduced by a certain erbium ion concentration in the ring-shaped region, and the 'clustering' phenomenon can be generated by increasing the erbium ion concentration in the erbium-doped fiber. The erbium-ytterbium double-clad double-ring-shaped gain fiber is designed, on one hand, the doping content of erbium ions is improved by introducing ytterbium ions so as to improve the gain of each mode, and on the other hand, the tail part of an evanescent field of a signal mode is utilized by adding an outer ring into an inner clad so as to further improve the gain.
Drawings
Fig. 1 is a cross-sectional view of an erbium ytterbium co-doped double-clad double-ring-shaped few-mode optical fiber according to an embodiment of the present invention;
fig. 2 is a refractive index profile and a dopant ion concentration profile of an erbium ytterbium co-doped double-clad double-ring-shaped few-mode optical fiber according to an embodiment of the present invention;
fig. 3 is a schematic structural diagram of an erbium-ytterbium co-doped double-clad double-loop few-mode fiber used in a few-mode erbium-doped fiber amplifier according to an embodiment of the present invention.
Detailed Description
In order to make the objects, technical solutions and advantages of the present invention more apparent, the present invention is described in further detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative of the invention and are not intended to limit the invention. In addition, the technical features involved in the embodiments of the present invention described below may be combined with each other as long as they do not conflict with each other.
The invention provides an erbium ytterbium co-doped double-clad double-ring-shaped few-mode gain fiber, as shown in fig. 1, the cross-sectional schematic diagram of which is shown in fig. 1, the few-mode gain fiber comprises from inside to outside: the fiber core comprises a fiber core 1-2, an inner ring 1-1, an inner cladding 1-4 and an outer cladding 1-5, wherein an outer ring 1-3 is arranged in the middle of the inner cladding 1-4; wherein the cross sections of the fiber core 1-2, the inner ring 1-1, the outer ring 1-3 and the outer cladding 1-5 are all circular; the cross section of the inner cladding layers 1-4 is an irregular polygon; the fiber core 1-2 is made of quartz material doped with ions; the inner ring 1-1 and the outer ring 1-3 are doped with rare earth ions, and the rare earth ions comprise erbium ions and ytterbium ions; the refractive index is gradually reduced from the fiber core 1-2 to the junction with the inner cladding 1-4, and is kept constant in the inner cladding 1-4, and the refractive index of the outer cladding 1-5 is lower than that of the inner cladding 1-4.
The invention provides an erbium-ytterbium co-doped double-clad double-ring-shaped few-mode gain optical fiber which comprises an inner ring 1-1, a fiber core 1-2, an outer ring 1-3, an inner cladding 1-4 and an outer cladding 1-5, wherein the fiber core 1-2 wraps the inner ring 1-1, the outer ring 1-3 is positioned outside the fiber core 1-2 and inside the inner cladding 1-4, and the outer cladding 1-5 wraps the inner cladding 1-4, so that the double-clad double-ring-shaped few-mode gain optical fiber is integrally formed. Wherein, the cross sections of the fiber core 1-2, the inner ring 1-1, the outer ring 1-3 and the outer cladding 1-5 are circular, and the cross section of the inner cladding 1-4 is D-shaped, eccentric circular or polygonal, which is exemplified by D-shaped in the patent. The outer diameter of the inner ring 1-1 is inscribed in the fiber core 1-2, the inner diameter of the outer ring 1-3 is larger than the radius of the fiber core 1-2, and the outer diameter of the outer ring 1-3 is not larger than the radius of an inscribed circle of the inner cladding 1-4. The few-mode gain fiber has gradient refractive index distribution, and the doped rare earth ions in the double rings are erbium ions and ytterbium ions.
In the design of the optical fiber according to practical application, the diameter of a fiber core 1-2 is not more than 20 microns, the inner diameter of an inner ring 1-1 is 0.48 times of the radius of the fiber core 1-2, the inner diameter of an outer ring 1-3 is larger than the radius of the fiber core 1-2, the outer diameter of the outer ring 1-3 is not more than the radius of an inscribed circle of an inner cladding 1-4, and the width of the outer ring 1-3 can be properly optimized and adjusted; the diameter of the inner cladding 1-4 is about 125 microns, and the diameter of the outer cladding 1-5 is greater than that of the inner cladding 1-4. The gain fiber is made of an ion-doped quartz material, rare earth ions are doped only in the double rings, the doped rare earth ions are erbium ions and ytterbium ions, and the concentration of the doped ions can be properly optimized and adjusted. FIG. 2 is a graph showing the refractive index profile and dopant ion concentration of an erbium-ytterbium co-doped double-clad double-ring few-mode fiber of the present invention.
In one embodiment, the inner cladding 1-4 has a cross-section that is "D" shaped, eccentric circular or "plum blossom" shaped.
In one embodiment, the inner diameter of the outer ring 1-3 is greater than or equal to the outer diameter of the inner ring 1-1; the outer diameter of the outer ring 1-3 is less than or equal to the radius of the corresponding inscribed circle of the inner cladding 1-4; the width of the outer rings 1-3 can be adjusted.
In one embodiment, the core 1-2 has a diameter of less than 20 microns.
In one embodiment, the inner diameter of the inner ring 1-1 is 0.48 times the radius of the core 1-2, and the diameter of the inner cladding 1-4 is about 125 microns.
In one embodiment, when the few-mode gain fiber is used as a gain medium, the few-mode gain fiber is cladding pumped by a multimode pump light source. In one embodiment, the pumping mode adopts forward pumping or backward pumping.
Specifically, when the erbium-ytterbium co-doped double-clad double-annular few-mode fiber is used as a gain medium, a multi-mode pump light source needs to be used for cladding pumping, and the pumping mode can be forward pumping or backward pumping.
According to another aspect of the present invention, there is provided a few-mode erbium-doped fiber amplifier, comprising:
signal light providing means for providing signal light;
a multimode pump light source for emitting pump light;
the beam combiner is used for combining the signal light and the pump light to obtain coupled light;
the few-mode gain optical fiber is arranged on an emergent light path of the coupled light and is used for amplifying the coupled light to obtain amplified light;
and the spectrum detection device is arranged on the transmission light path of the amplified light and is used for collecting the light spots of the amplified light and measuring the power of the amplified light.
Specifically, the present invention further provides a structural schematic diagram of an erbium-ytterbium co-doped double-clad double-ring few-mode fiber used for a few-mode erbium-doped fiber amplifier, the structure of which is shown in fig. 3, and the structural schematic diagram includes an erbium-ytterbium co-doped double-clad double-ring few-mode fiber 1, a signal light source 2, a tunable attenuator 3, a polarization controller 4, an optical isolator 5, a mode selection photon lantern 6, a beam combiner 7, a multimode pump light source 8, a charge coupler camera 9, a spectrometer 10, and a multimode jumper 11 of an FC/APC port. The mode selection photon lantern 6 comprises six signal mode input arms and one signal output arm; one end of the beam combiner 7 comprises a pump input arm and a signal input arm, and the other end is a signal output arm.
The seed light is provided by the signal light source 2; the tunable attenuator 3 adjusts the signal light power and controls the input power of each signal mode; the polarization controller 4 is used to ensure the purity of the converted signal mode; after the optical isolator, the signal fundamental mode LP01 is coupled to one input branch (LP01, LP11a, LP11b, LP21a, LP21b, or LP02) of the mode-selective photonic lantern, which converts the signal into its supported modes; the pump light is provided by a multimode pump light source; then, the combiner 7 couples the signal light and the pump light, and inputs the coupled signal light and pump light into the erbium-ytterbium co-doped double-clad double-ring few-mode fiber for amplification, and the tail end of the few-mode fiber is welded with a multimode jumper wire of an FC/APC port, so that the input spectrometer can measure the output power conveniently. The spots are collected using a charge-coupled camera.
The erbium ytterbium co-doped double-clad double-ring multimode fiber 1 used in example 1 was the erbium ytterbium co-doped double-clad double-ring multimode fiber of example 1, that is: the erbium ytterbium co-doped double-clad double-ring few-mode optical fiber comprises an inner ring 1-1, a fiber core 1-2, an outer ring 1-3, an inner cladding 1-4 and an outer cladding 1-5, wherein the fiber core 1-2 wraps the inner ring 1-1, the outer ring 1-3 is located outside the fiber core 1-2 and inside the inner cladding 1-4, and the outer cladding 1-5 wraps the inner cladding 1-4 to integrally form the double-clad double-ring few-mode gain optical fiber. Furthermore, the cross sections of the fiber core 1-2, the inner ring 1-1, the outer ring 1-3 and the outer cladding 1-5 are circular, and the cross section of the inner cladding 1-4 is D-shaped, eccentric circular or polygonal. The outer diameter of the inner ring 1-1 is inscribed in the fiber core 1-2, the inner diameter of the outer ring 1-3 is larger than the radius of the fiber core 1-2, and the outer diameter of the outer ring 1-3 is not larger than the radius of an inscribed circle of the inner cladding 1-4. The inner diameter of the inner ring 1-1 is 0.48 times the radius of the core 1-2, and the diameter of the core 1-2 is not more than 20 microns. The inner diameter of the outer ring 1-3 is larger than the radius of the fiber core 1-2, the outer diameter of the outer ring 1-3 is not larger than the radius of the inscribed circle of the inner cladding 1-4, and the width of the outer ring 1-3 can be properly optimized and adjusted; the diameter of the inner cladding layers 1-4 is about 125 micrometers; the diameter of the outer cladding 1-5 is larger than that of the inner cladding 1-4. The refractive index distribution of the gain fiber is graded-index distribution, namely, in the fiber core 1-2, the refractive index is gradually reduced from the center of the fiber core 1-2 to the junction of the fiber core 1-2 and the inner cladding 1-4, the refractive index is constant in the inner cladding 1-4, and the refractive index of the outer cladding 1-5 is lower than that of the inner cladding 1-4. The gain fiber is made of an ion-doped quartz material, rare earth ions are doped only in the double rings, the doped rare earth ions are erbium ions and ytterbium ions, and the concentration of the doped ions can be properly optimized and adjusted.
Because the amplifier of the embodiment uses the erbium-ytterbium co-doped double-clad double-ring few-mode fiber, the ring structure in the fiber core 1-2 is doped, and the gain can be balanced to a certain degree; the doped outer rings 1-3 in the inner cladding layers 1-4 can utilize the tail part of an evanescent field of a signal mode, and are favorable for improving the gain of the annular optical fiber; and ytterbium ions are introduced into the double-ring-shaped doping area, so that the doping concentration of erbium ions is improved, and the gain of the amplifier can be further improved.
It will be understood by those skilled in the art that the foregoing is only an exemplary embodiment of the present invention, and is not intended to limit the invention to the particular forms disclosed, since various modifications, substitutions and improvements within the spirit and scope of the invention are possible and within the scope of the appended claims.
Claims (8)
1. An erbium ytterbium co-doped double-clad double-ring few-mode gain optical fiber, which is characterized by comprising from inside to outside: the fiber core (1-2), the inner ring (1-1), the inner cladding (1-4) and the outer cladding (1-5), wherein the outer ring (1-3) is arranged in the middle of the inner cladding (1-4); wherein the content of the first and second substances,
the cross sections of the fiber core (1-2), the inner ring (1-1), the outer ring (1-3) and the outer cladding (1-5) are all circular; the cross section of the inner cladding (1-4) is irregular polygon;
the fiber core (1-2) is made of quartz material doped with ions; the inner ring (1-1) and the outer ring (1-3) are doped with rare earth ions, wherein the rare earth ions comprise erbium ions and ytterbium ions;
the refractive index is gradually reduced from the fiber core (1-2) to the junction with the inner cladding (1-4), the refractive index of the outer cladding (1-5) is lower than that of the inner cladding (1-4), and the inner cladding (1-4) is kept unchanged.
2. The erbium ytterbium co-doped double-clad double-ring type few-mode gain fiber of claim 1, wherein the inner cladding (1-4) has a cross-section of "D" shape, eccentric circular shape or "plum" shape.
3. The erbium ytterbium co-doped double-clad double-annular few-mode gain fiber of claim 1 or 2, wherein the inner diameter of the outer ring (1-3) is greater than or equal to the outer diameter of the inner ring (1-1); the outer diameter of the outer ring (1-3) is less than or equal to the radius of the corresponding inscribed circle of the inner cladding (1-4); the width of the outer rings (1-3) can be adjusted.
4. The erbium ytterbium co-doped double-clad double-annular few-mode gain fiber of claim 1, wherein the core (1-2) has a diameter lower than 20 μm.
5. The erbium ytterbium co-doped double-clad double-ring type few-mode gain fiber of claim 4, wherein the inner diameter of the inner ring (1-1) is 0.48 times the radius of the core (1-2), and the diameter of the inner cladding (1-4) is about 125 μm.
6. The erbium ytterbium co-doped double-clad double-annular few-mode gain fiber of claim 1, wherein the few-mode gain fiber is cladding pumped with a multimode pump light source when it is used as a gain medium.
7. The erbium ytterbium co-doped double-clad double-annular few-mode gain fiber of claim 6, wherein the pumping is forward or backward pumped.
8. A few-mode erbium-doped fiber amplifier, comprising:
signal light providing means for providing signal light;
a multimode pump light source for emitting pump light;
the beam combiner is used for combining the signal light and the pump light to obtain coupled light;
the few-mode gain optical fiber of any one of claims 1 to 7, disposed in an exit path of the coupled light, for amplifying the coupled light to obtain amplified light;
and the spectrum detection device is arranged on the transmission light path of the amplified light and is used for collecting the light spots of the amplified light and measuring the power of the light spots.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202210707185.4A CN115047561B (en) | 2022-06-21 | 2022-06-21 | Erbium-ytterbium co-doped double-cladding double-annular few-mode gain optical fiber |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202210707185.4A CN115047561B (en) | 2022-06-21 | 2022-06-21 | Erbium-ytterbium co-doped double-cladding double-annular few-mode gain optical fiber |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| CN115047561A true CN115047561A (en) | 2022-09-13 |
| CN115047561B CN115047561B (en) | 2023-07-25 |
Family
ID=83163586
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN202210707185.4A Active CN115047561B (en) | 2022-06-21 | 2022-06-21 | Erbium-ytterbium co-doped double-cladding double-annular few-mode gain optical fiber |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN115047561B (en) |
Citations (7)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2003227944A (en) * | 2002-02-04 | 2003-08-15 | Mitsubishi Cable Ind Ltd | Doubly clad fiber and method of manufacturing the same |
| CN101067671A (en) * | 2007-06-01 | 2007-11-07 | 中国科学院上海光学精密机械研究所 | Leakage structure large mode field double-cladding single mode yb doped-optical fiber |
| CN108152883A (en) * | 2018-01-09 | 2018-06-12 | 北京交通大学 | Negative double clad tapered active optical fiber |
| US20210242652A1 (en) * | 2020-01-31 | 2021-08-05 | Institut National D'optique | Multi-clad optical fiber with delocalization of pedestal modes |
| CN113820783A (en) * | 2021-08-12 | 2021-12-21 | 江苏法尔胜光电科技有限公司 | Photosensitive erbium-ytterbium co-doped optical fiber for high power and preparation method thereof |
| CN113917599A (en) * | 2021-09-24 | 2022-01-11 | 中国科学院西安光学精密机械研究所 | Large-mode-field single-mode irradiation-resistant erbium-ytterbium co-doped fiber and preparation method thereof |
| CN114573226A (en) * | 2022-03-28 | 2022-06-03 | 浙江热刺激光技术有限公司 | Active optical fiber and preparation method thereof |
-
2022
- 2022-06-21 CN CN202210707185.4A patent/CN115047561B/en active Active
Patent Citations (7)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2003227944A (en) * | 2002-02-04 | 2003-08-15 | Mitsubishi Cable Ind Ltd | Doubly clad fiber and method of manufacturing the same |
| CN101067671A (en) * | 2007-06-01 | 2007-11-07 | 中国科学院上海光学精密机械研究所 | Leakage structure large mode field double-cladding single mode yb doped-optical fiber |
| CN108152883A (en) * | 2018-01-09 | 2018-06-12 | 北京交通大学 | Negative double clad tapered active optical fiber |
| US20210242652A1 (en) * | 2020-01-31 | 2021-08-05 | Institut National D'optique | Multi-clad optical fiber with delocalization of pedestal modes |
| CN113820783A (en) * | 2021-08-12 | 2021-12-21 | 江苏法尔胜光电科技有限公司 | Photosensitive erbium-ytterbium co-doped optical fiber for high power and preparation method thereof |
| CN113917599A (en) * | 2021-09-24 | 2022-01-11 | 中国科学院西安光学精密机械研究所 | Large-mode-field single-mode irradiation-resistant erbium-ytterbium co-doped fiber and preparation method thereof |
| CN114573226A (en) * | 2022-03-28 | 2022-06-03 | 浙江热刺激光技术有限公司 | Active optical fiber and preparation method thereof |
Also Published As
| Publication number | Publication date |
|---|---|
| CN115047561B (en) | 2023-07-25 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| JP6794310B2 (en) | Multi-core erbium-doped fiber amplifier | |
| Jain et al. | 32-core erbium/ytterbium-doped multicore fiber amplifier for next generation space-division multiplexed transmission system | |
| Ono et al. | 2-LP mode few-mode fiber amplifier employing ring-core erbium-doped fiber | |
| Tsuchida et al. | Cladding pumped seven-core EDFA using an absorption-enhanced erbium doped fibre | |
| WO2021129182A1 (en) | Fiber amplifier | |
| WO2020181586A1 (en) | Low differential mode gain few-mode erbium-doped fiber amplifier | |
| CN112510472B (en) | Few-mode erbium-doped optical fiber and few-mode erbium-doped optical fiber amplifier | |
| CA2276997C (en) | Optical fiber for optical amplifier and fiber optic amplifier | |
| Jung et al. | Multicore and multimode optical amplifiers for space division multiplexing | |
| Abedin et al. | State-of-the-art multicore fiber amplifiers for space division multiplexing | |
| AU2020101195A4 (en) | An ultra-wideband high gain multi-core fiber light source | |
| Mélin et al. | Power efficient all-fiberized 12-core erbium/ytterbium doped optical amplifier | |
| Amma et al. | Ring-core multicore few-mode erbium-doped fiber amplifier | |
| Abedin et al. | Space division multiplexed multicore erbium-doped fiber amplifiers | |
| JPH11121839A (en) | Optical amplification fiber and optical fiber amplifier | |
| CN115047561B (en) | Erbium-ytterbium co-doped double-cladding double-annular few-mode gain optical fiber | |
| Ono et al. | Amplification technology for multi-core fiber transmission | |
| Alam et al. | Current status of few mode fiber amplifiers for spatial division multiplexed transmission | |
| Wang et al. | Low-crosstalk few-mode EDFAs using retro-reflection for single-mode fiber trunk lines and networks | |
| Qiu et al. | Powerful trade-off between DMG and gain characteristics in the l-band high-numerical aperture few-mode erbium-doped fiber amplifier | |
| Jung et al. | High spatial density 6-mode 7-core multicore L-band fiber amplifier | |
| LaRochelle et al. | Cladding pumped multi-core fiber amplifiers for space division multiplexing | |
| CN115149377A (en) | Few-mode erbium-doped fiber amplifier system | |
| CN220492413U (en) | Multichannel light-emitting system based on multi-concentration erbium-doped fiber | |
| Xu et al. | Modal superposition and gain competition in clad-pump few-mode EDFA |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| PB01 | Publication | ||
| PB01 | Publication | ||
| SE01 | Entry into force of request for substantive examination | ||
| SE01 | Entry into force of request for substantive examination | ||
| GR01 | Patent grant | ||
| GR01 | Patent grant |