CN113703158B - Rapid design method of few-mode optical fiber gain profile for intermode gain equalization - Google Patents

Rapid design method of few-mode optical fiber gain profile for intermode gain equalization Download PDF

Info

Publication number
CN113703158B
CN113703158B CN202111043042.XA CN202111043042A CN113703158B CN 113703158 B CN113703158 B CN 113703158B CN 202111043042 A CN202111043042 A CN 202111043042A CN 113703158 B CN113703158 B CN 113703158B
Authority
CN
China
Prior art keywords
gain
mode
optical fiber
layer
design
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.)
Active
Application number
CN202111043042.XA
Other languages
Chinese (zh)
Other versions
CN113703158A (en
Inventor
郑晶晶
裴丽
赵琦
常彦彪
王建帅
李祉祺
宁提纲
李晶
宋豫婧
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Beijing Jiaotong University
Original Assignee
Beijing Jiaotong University
Priority date (The priority date 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 date listed.)
Filing date
Publication date
Application filed by Beijing Jiaotong University filed Critical Beijing Jiaotong University
Priority to CN202111043042.XA priority Critical patent/CN113703158B/en
Publication of CN113703158A publication Critical patent/CN113703158A/en
Application granted granted Critical
Publication of CN113703158B publication Critical patent/CN113703158B/en
Active legal-status Critical Current
Anticipated expiration legal-status Critical

Links

Images

Classifications

    • GPHYSICS
    • G02OPTICS
    • G02BOPTICAL ELEMENTS, SYSTEMS OR APPARATUS
    • G02B27/00Optical systems or apparatus not provided for by any of the groups G02B1/00 - G02B26/00, G02B30/00
    • G02B27/0012Optical design, e.g. procedures, algorithms, optimisation routines

Abstract

The invention discloses a method for quickly designing a few-mode optical fiber gain section for gain equalization among modes, which quickly and efficiently realizes the design of the few-mode optical fiber gain section by simplifying a gain section design model and solving the idea. According to the method for rapidly designing the few-mode optical fiber gain profile for the intermode gain equalization, which is provided by the invention, a mathematical model is simple and easy to operate, the typical completion time under the computer-aided calculation condition is within 1 minute, the design time is obviously reduced, the solution can be realized through manual calculation under the extreme condition, and the dependence degree of the design on the computer-aided calculation is reduced.

Description

Rapid design method of few-mode optical fiber gain profile for intermode gain equalization
Technical Field
The invention belongs to the technical field of optical fibers, and particularly relates to a method for quickly designing a few-mode optical fiber gain profile for intermode gain equalization.
Background
Under the huge pressure of the current communication demand, space division multiplexing is a novel multiplexing scheme for improving the current communication capacity in multiples. The scheme has gained wide attention at home and abroad, and is generally considered as a key technology for solving the communication requirement at the next stage. For relay amplification of an undisrupted signal in long-distance transmission of optical communication, a basic problem of rare earth doped optical fiber suitable for requirements of a space division multiplexing optical fiber amplifier must be solved for constructing an optical amplifier of a space division multiplexing communication system.
Amplification is achieved in conventional single mode fiber communication systems primarily by rare earth doped active fiber amplifiers, of which erbium doped fiber based amplifiers have gained widespread use. The high gain characteristic of the rare earth doped fiber can be transferred to the space division multiplexing active fiber through a common preparation process, so that the problem to be solved most urgently by the space division multiplexing amplifier is that the gain difference of each mode is large, so that obvious signal power difference appears after amplification, and the system interruption probability is easily increased due to multiple accumulation in transmission, so that the bit error rate of a receiving end is increased.
The source of solving the mode gain difference problem lies in the gain profile design of the few-mode active optical fiber. The structural design of the optical fiber comprises a refractive index profile design and a gain profile design, wherein the refractive index profile design determines the characteristics of the optical fiber such as cut-off wavelength, mode number, mode field distribution, dispersion and the like, and the gain profile design determines the mode gain and the mode-to-mode gain difference of the optical fiber. The fiber refractive index profile is the most interesting issue for passive fibers for transmission, and the amplifier section focuses more on the design of the gain profile of active fibers.
The profile in the field of optical fibers refers specifically to the distribution of the profile over the cross-section of the optical fiber, for example, the refractive index profile or the gain profile of most of the few-mode optical fibers can be represented by the concentric circle structure shown in fig. 1 and 2. The optical fiber main body structure is composed of two parts: a core 1 with a high refractive index, and a cladding 2 with a low refractive index concentric with and surrounding the core. According to the difference of refractive index or doping concentration of gain particles, the fiber core 1 can be divided into a plurality of concentric circle regions, 11, 12, 13 and 14 from inside to outside in the figure, corresponding to the refractive index n1、n2、n3、n4And doping concentration ratio a1、a2、a3、a4As noted in the figures.
In the existing reports, software is written to carry out numerical operation to obtain more reasonable gain profile parameters mainly through a reverse design idea and by adopting methods such as a neural network and a genetic algorithm. At present, no commercial software exists in the design method, the model is complex, and the compiling difficulty is high, so that only few units can realize the gain section design through reverse design. The reverse design process involves a large amount of parameter adjustment and amplification characteristic calculation, and the design is time-consuming. Given a refractive index profile, the time required to perform a gain profile design once is typically over twenty hours.
Disclosure of Invention
The invention provides a method for quickly designing a few-mode optical fiber gain section for intermode gain equalization, which aims to quickly and efficiently realize the design of the few-mode optical fiber gain section by simplifying a gain section design model and a solution thought.
The technical scheme adopted by the invention is as follows:
a method for quickly designing a few-mode optical fiber gain profile for intermode gain equalization is characterized by comprising the following steps:
s1, obtaining refractive index profile parameters of the optical fiber, including the radius of each concentric circle and the refractive index of each layer;
s2, judging whether the optical fiber belongs to a step multilayer structure or not according to the refractive index profile parameters obtained in the step S1; if not, determining the number n of layers of the gain profile; if yes, go to S3;
s3: if the optical fiber is of a step multilayer structure, directly using the layered structure of the refractive index profile in the design of the gain profile to obtain the corresponding doping layering number n of the gain particles;
s4: obtaining the number m of modes supported by the optical fiber and the field distribution of each mode according to the refractive index profile by the aid of a classical solution method or simulation software
Figure GDA0003580799120000031
S5: calculating a filling factor matrix gamma of each mode in each doping layer according to the field distribution and the layering structure of each modemnWherein matrix element γijFill factor at j layer for i mode, i.e.The power of the ith mode at the jth layer is simply calculated as the ratio of the total power carried by the mode:
Figure GDA0003580799120000032
s6: using a fill factor matrix ΓmnThe evaluation factors of each mode are constructed, and the doping concentration coefficients of the 1 st layer to the n-th layer are respectively a1To anEvaluation factor e of the i-th modeiCan be expressed as:
Figure GDA0003580799120000033
when the evaluation factors are equal, obtaining the doping concentration coefficient of each layer to be solved; i.e. to solve a system of equations comprising m equations:
e1=e2=...=em-1=em=1 (3)
the following substitution is made for,
Figure GDA0003580799120000034
the system of equations can be rewritten in the form of a matrix equation
ΓA=1 (5)
Judging the magnitude relation between m and n, if m is less than n, obtaining a group of proportional relations by the equation set, wherein the proportional relations are the doping concentration ratios of all layers of the gain section; if m > n, the constraint condition of the equation set is more than the number of unknowns, the equation set is not solved, and S7 is executed.
S7: and (4) converting into a solution of the over-determined equation problem, namely finding a least square solution of the over-determined equation gamma A-1. The solution can be done manually or computer-aided. So far, the first round of parameter calculation is completed.
S8: the number of virtual subdivision levels s per level is set. The number of calculated layers divided at this time is s · n in total, but the number of doping profile layers n is not changed, and the doping concentration still has only n different values.
S9: according to the definition and formula provided by S5, calculating filling factors of each mode in each layer containing the virtual subdivision layer, and constructing a new matrix Γ S according to the following rulemn
Figure GDA0003580799120000041
Where the subscript jk denotes the kth subdivided layer of the jth layer.
S10: and solving the overdetermined equation set gamma SA 1 manually or by a computer.
S11: and (5) checking the residual error of the over-determined equation under two times of calculation. And if the residual difference is larger than the set threshold delta, increasing the S, and repeating the steps S8-S11 until the threshold requirement is met, thereby completing the design.
Preferably, the method can also determine the completion of the design by directly comparing the evaluation factor difference with the threshold. That is, after S7 or S10 is finished, the corresponding evaluation factors e of each mode are directly calculated at the current timeiAnd (5) performing difference, comparing with a set threshold delta, and finishing the design if the difference is smaller than the threshold.
The invention has the beneficial effects that:
the invention does not need complex methods such as neural network, genetic algorithm and the like, does not relate to amplification characteristic calculation, and has extremely simple program compiling; the mathematical model in the invention is simple and easy to operate, the typical completion time under the computer-aided calculation condition is within a few minutes, the design time consumption is obviously reduced, and the solution can be realized through manual calculation under the extreme condition, so that the dependence degree of the design on the computer-aided calculation is reduced.
Drawings
FIG. 1 is a schematic cross-sectional view of a concentric-circle-structured few-mode optical fiber in the prior art;
FIG. 2 is a schematic diagram of a refractive index profile and a gain profile of a concentric-circle-structured few-mode optical fiber in the prior art;
fig. 3 is a flowchart of a method for rapidly designing a few-mode fiber gain profile for gain equalization between modes according to 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 further described in detail with reference to the following 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.
Aiming at the problems of high threshold, high difficulty, long time consumption and the like of the current few-mode optical fiber gain section design, the invention provides a method for quickly designing a few-mode optical fiber gain section for gain equalization among modes, which is shown in figure 3 and comprises the following steps:
s1, obtaining refractive index profile parameters of the optical fiber, such as the radius of each concentric circle and the refractive index of each layer shown in FIG. 1;
s2, judging whether the optical fiber belongs to a step multilayer structure or not according to the refractive index profile parameters obtained in the step S1; if not, determining the number n of layers of the gain profile; if yes, go to S3;
s3: if the optical fiber is of a step multilayer structure, directly using the layered structure of the refractive index profile in the design of the gain profile to obtain the corresponding doping layering number n of the gain particles;
s4: obtaining the number m of modes supported by the optical fiber and the field distribution of each mode according to the refractive index profile by the aid of a classical solution method or simulation software
Figure GDA0003580799120000051
S5: calculating a filling factor matrix gamma of each mode in each doping layer according to the field distribution and the layering structure of each modemnWherein matrix element γijThe filling factor of the ith pattern at the jth layer, i.e. the ratio of the power of the ith pattern at the jth layer in the total power carried by the pattern, can be simply calculated by the following formula:
Figure GDA0003580799120000061
s6: using a fill factor matrix ΓmnThe evaluation factors of each mode are constructed, and the doping concentration coefficients of the 1 st layer to the n-th layer are respectively a1To anEvaluation factor e of the i-th modeiCan be expressed as:
Figure GDA0003580799120000062
when the evaluation factors are equal, obtaining the doping concentration coefficient of each layer to be solved; i.e. to solve a system of equations comprising m equations:
e1=e2=...=em-1=em=1 (3)
the following substitution is made for,
Figure GDA0003580799120000063
the system of equations may be rewritten as a matrix equation
ΓA=1 (5)
Judging the magnitude relation between m and n, if m is less than n, obtaining a group of proportional relations by the equation set, wherein the proportional relations are the doping concentration ratios of all layers of the gain section; if m > n, the constraint condition of the equation set is more than the number of unknowns, the equation set is not solved, and S7 is executed.
S7: and (4) converting into a solution of the over-determined equation problem, namely finding a least square solution of the over-determined equation gamma A-1. The solution can be performed manually or computer-aided. So far, the first round of parameter calculation is completed.
S8: the number of virtual subdivision levels s per level is set. The number of calculated layers divided at this time is s · n in total, but the number of doping profile layers n is not changed, and the doping concentration still has only n different values.
S9: according to the definition and formula provided by S5, calculating filling factors of each mode in each layer containing the virtual subdivision layer, and constructing a new matrix Γ S according to the following rulemn
Figure GDA0003580799120000071
Where the subscript jk denotes the kth subdivided layer of the jth layer.
S10: and solving the overdetermined equation set gamma SA 1 manually or by a computer.
S11: and (5) checking the residual error of the over-determined equation under two times of calculation. And if the residual difference is larger than the set threshold delta, increasing the S, and repeating the steps S8-S11 until the threshold requirement is met, thereby completing the design.
Preferably, the method can also determine the completion of the design by directly comparing the evaluation factor difference with the threshold. That is, after S7 or S10 is finished, the corresponding evaluation factors e of each mode are directly calculated at the current timeiAnd (5) performing difference, comparing with a set threshold delta, and finishing the design if the difference is smaller than the threshold.
Example one
As shown in fig. 3, the method for designing the gain profile of the few-mode optical fiber for gain equalization between modes disclosed in the present invention includes the following steps for the optical fiber with the refractive index profile parameters shown in table 1 below:
and S1, acquiring the refractive index profile parameters of the optical fiber. The parameters of the refractive index profile used in this example are shown in table 1 below;
TABLE 1 refractive index parameters for a three-core fiber used in example one
Radius (mum) 3 6.26 10 14 20 62.5
Refractive index 1.4488 1.4512 1.4500 1.4440 1.4370 1.4440
The refractive index profile of the fiber is 6 layers in total. The outermost side is a cladding; the inner three layers have refractive indexes higher than that of the cladding and are multilayer regions designed relative to a gain section; the outer 3 layers are cladding and transition layers, which only affect the mode characteristics and do not incorporate the gain profile design.
And S2, judging that the optical fiber belongs to the step multilayer structure according to the refractive index profile parameters obtained in the step S1. Execution of S3;
s3: directly using the layered structure of the refractive index profile in the design of the gain profile to obtain the corresponding doping layering number 3 of the gain particles;
s4: according to the refractive index profile, 5 modes which can be supported by the optical fiber and field distribution phi of each mode are obtained by the assistance of simulation software COMSOLMUTIPhysics1~φ5
S5: calculating a filling factor matrix gamma of each mode in each doping layer according to the field distribution and the layering structure of each modemn
Figure GDA0003580799120000081
S6: using a fill factor matrix ΓmnThe evaluation factors of each mode are constructed, and the doping concentration coefficients of the 1 st layer to the 3 rd layer are respectively a1To a3,A=[a1,a2,a3]T,
The system of equations can be rewritten in the form of a matrix equation
ΓA=1 (9)
The matrix equation m is 5, n is 3, m > n is satisfied, the constraint condition of the equation set is more than the number of unknowns, the equation set is not solved, and S7 is executed.
S7: and (4) converting into a solution of the over-determined equation problem, namely finding a least square solution of the over-determined equation gamma A-1. The solution of the over-determined equation is obtained by Matlab software aided solution as a ═ 1.280950865,0.758076479,1.303455178]T. So far, the first round of parameter calculation is completed.
And judging the completion of the design by adopting an evaluation factor. After S7 or S10 is finished, the corresponding evaluation factors e of each mode are directly calculated at the current timeiAnd (5) performing difference, comparing with a set threshold delta, and finishing the design if the difference is smaller than the threshold. In this embodiment, S7 is used to find the evaluation factor e of each mode corresponding to aiAnd the corresponding differences are shown in table 2 below.
Table 2 example evaluation factors and differences for each mode
Mode 1 Mode 2 Mode 3 Mode 4 Mode 5
Evaluation factor ei 0.992229367 1.001114996 1.020454713 1.004063661 0.98129069
Difference value - 0.008885629 0.028225345 0.011834294 -0.010938678
For the set threshold δ of 0.05, the present embodiment determines that the design is complete when the difference between the evaluation factors corresponding to the respective modes is smaller than δ as a result obtained in step S7. The gain profile design parameters obtained in this example are shown in table 3 below.
TABLE 3 example gain Profile parameters
Figure GDA0003580799120000091
It will be understood by those skilled in the art that the above-described types of parameters of the core, cladding and rare earth doped region are merely exemplary, and that other types of applications of the core, cladding and rare earth doped region, which are currently or later become known and may be used in the embodiments of the present invention, are also included within the scope of the present invention and are hereby incorporated by reference.
The above description is only for the preferred embodiment of the present invention, but the scope of the present invention is not limited thereto, and any changes or substitutions that can be easily conceived by those skilled in the art within the technical scope of the present invention are included in the scope of the present invention. Therefore, the protection scope of the present invention shall be subject to the protection scope of the claims.

Claims (2)

1. A method for quickly designing a few-mode optical fiber gain profile for intermode gain equalization is characterized by comprising the following steps:
s1, obtaining refractive index profile parameters of the optical fiber;
s2, judging whether the optical fiber belongs to a step multilayer structure or not according to the refractive index profile parameters obtained in the step S1; if not, determining the number n of layers of the gain profile; if yes, go to S3;
s3: if the optical fiber is of a step multilayer structure, directly using the layered structure of the refractive index profile in the design of the gain profile to obtain the corresponding doping layering number n of the gain particles;
s4: obtaining the number m of modes supported by the optical fiber and the field distribution of each mode according to the refractive index profile by the aid of a classical solution method or simulation software
Figure FDA0003566053520000011
S5: according to the distribution and the layered structure of each mode field, calculating a filling factor matrix gamma of each mode in each doping layermnWherein matrix element γijThe filling factor of the ith pattern at the jth layer, i.e. the ratio of the power of the ith pattern at the jth layer in the total power carried by the pattern, can be calculated by the following formula:
Figure FDA0003566053520000012
s6: using fill factor matrix ΓmnThe evaluation factors of each mode are constructed, and the doping concentration coefficients of the 1 st layer to the n-th layer are respectively a1To anEvaluation factor e of the i-th modeiCan be expressed as:
Figure FDA0003566053520000013
when the evaluation factors are equal, obtaining the doping concentration coefficient of each layer to be solved; i.e. to solve a system of equations comprising m equations:
e1=e2=…=em-1=em=1 (3)
the following substitution is made for,
Figure FDA0003566053520000021
the system of equations can be rewritten in the form of a matrix equation:
ΓA=1 (5)
judging the magnitude relation between m and n, if m is less than n, obtaining a group of proportional relations by the equation set, wherein the proportional relations are the doping concentration ratios of all layers of the gain section; if m is greater than n, the constraint condition of the equation set is more than the number of unknown numbers, the equation set is not solved, and S7 is executed;
s7: converting into a problem of solving an overdetermined equation, namely finding a least square solution of the overdetermined equation gamma A1, and solving to complete the first round of parameter calculation;
s8: setting the number s of virtual fine layers of each layer, wherein the number of divided calculated layers is s.n layers in total, but the number n of doping section layers is not changed, and the doping concentration still has n different values;
s9: according to the definition and formula provided in step S5, calculating filling factors of each mode in each layer including the virtual subdivision layer, and constructing a new matrix Γ S according to the following rulemn
Figure FDA0003566053520000022
Wherein the subscript jk denotes the kth subdivided layer of the jth layer;
s10: solving an overdetermined equation set gamma SA (1);
s11: checking the residual error of the overdetermined equation under the two-time calculation; and if the residual difference is larger than the set threshold delta, increasing the S, and repeating the steps S8-S11 until the threshold requirement is met, thereby completing the design.
2. The method for rapidly designing a gain profile of a few-mode fiber for intermodal gain equalization according to claim 1, wherein:
design completion can also be determined by directly comparing the evaluation factor difference with a threshold, i.e.After S7 or S10 is finished, the corresponding evaluation factors e of each mode are directly calculated at the current timeiAnd (5) making a difference, comparing the difference with a set threshold delta, and finishing the design if the difference is smaller than the threshold.
CN202111043042.XA 2021-09-07 2021-09-07 Rapid design method of few-mode optical fiber gain profile for intermode gain equalization Active CN113703158B (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
CN202111043042.XA CN113703158B (en) 2021-09-07 2021-09-07 Rapid design method of few-mode optical fiber gain profile for intermode gain equalization

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
CN202111043042.XA CN113703158B (en) 2021-09-07 2021-09-07 Rapid design method of few-mode optical fiber gain profile for intermode gain equalization

Publications (2)

Publication Number Publication Date
CN113703158A CN113703158A (en) 2021-11-26
CN113703158B true CN113703158B (en) 2022-05-13

Family

ID=78660719

Family Applications (1)

Application Number Title Priority Date Filing Date
CN202111043042.XA Active CN113703158B (en) 2021-09-07 2021-09-07 Rapid design method of few-mode optical fiber gain profile for intermode gain equalization

Country Status (1)

Country Link
CN (1) CN113703158B (en)

Citations (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPH0733467A (en) * 1993-07-21 1995-02-03 Shin Etsu Chem Co Ltd Production of porous glass preform for optical fiber
CN1883085A (en) * 2003-11-19 2006-12-20 康宁股份有限公司 Active photonic band-gap optical fiber
CN111123427A (en) * 2020-01-20 2020-05-08 北京交通大学 Step-up type doped step-index few-mode optical fiber for mode gain equalization
CN111755938A (en) * 2020-06-22 2020-10-09 电子科技大学 Optimization design method of few-mode erbium-doped fiber amplifier

Family Cites Families (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US9077148B2 (en) * 2013-09-18 2015-07-07 Ofs Fitel, Llc Gain-equalized few-mode fiber amplifier

Patent Citations (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPH0733467A (en) * 1993-07-21 1995-02-03 Shin Etsu Chem Co Ltd Production of porous glass preform for optical fiber
CN1883085A (en) * 2003-11-19 2006-12-20 康宁股份有限公司 Active photonic band-gap optical fiber
CN111123427A (en) * 2020-01-20 2020-05-08 北京交通大学 Step-up type doped step-index few-mode optical fiber for mode gain equalization
CN111755938A (en) * 2020-06-22 2020-10-09 电子科技大学 Optimization design method of few-mode erbium-doped fiber amplifier

Non-Patent Citations (2)

* Cited by examiner, † Cited by third party
Title
A Mueller Matrix Formalism for Modeling Polarization Effects in Erbium-Doped Fiber;Jefferson L.Wagener,Dario G.Falquier,Michel J.F.Digonnet;《JOURNAL OF LIGHTWAVE TECHNOLOGY》;19980228;第16卷(第2期);全文 *
用于数字化标定的光纤光栅应变检测系统;王建颖,刘智超,林雪竹 等;《激光技术》;20200930;第44卷(第5期);全文 *

Also Published As

Publication number Publication date
CN113703158A (en) 2021-11-26

Similar Documents

Publication Publication Date Title
EP2852011B1 (en) Gain-equalized few-mode fiber amplifier
EP2541292B1 (en) Multimode optical fibre
CN108170950B (en) Multilayer frequency selection surface wave-absorbing material modeling optimization method based on neural network
CN109039766B (en) Power CPS network risk propagation threshold determination method based on seepage probability
CN111211471B (en) Optical fiber amplifier
CN110390461B (en) Nonlinear fuzzy language power distribution network node vulnerability evaluation method based on complex network
CN113703158B (en) Rapid design method of few-mode optical fiber gain profile for intermode gain equalization
CN112198587B (en) Multi-core few-mode optical fiber and method for determining parameters thereof
CN112099128A (en) Hierarchical doped step type weak coupling gain equalization four-mode erbium-doped optical fiber
CN105843733A (en) Big data platform performance detection method and device
CN103530700B (en) Urban distribution network saturation loading Comprehensive Prediction Method
CN111900720B (en) Transmission network fragile line identification method based on double-layer webpage sorting algorithm
CN105488270A (en) Multiattribute comprehensive method for structural fault diagnosis of transformer
CN111274624B (en) Multi-working-condition special-shaped node topology optimization design method based on RBF proxy model
Zhao et al. Demonstration of a ring-core few-mode erbium-doped fiber for mode gain equalization based on layered doping
CN202522729U (en) Nearly single-mode quasi gradient refractive index large mode field gain optical fiber
CN113156574B (en) Multi-parameter optimized orbital angular momentum erbium-doped optical fiber
CN115017741B (en) Reconstruction method and device for gas diffusion layer of fuel cell and electronic equipment
CN115954868A (en) Power grid safety analysis method, device and medium
CN108268982B (en) Large-scale active power distribution network decomposition strategy evaluation method and device
CN113917599B (en) Large-mode-field single-mode irradiation-resistant erbium-ytterbium co-doped fiber and preparation method thereof
CN113822538A (en) AHP-CRITIC-based small and medium-sized earth and rockfill dam operation evaluation method
CN113552719A (en) Multi-cladding optical fiber design method based on genetic algorithm
Tripathi et al. An Environmental Adaption Method with real parameter encoding for dynamic environment
CN112994078B (en) Cluster partition dividing method for high-density distributed power generation

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