The history, current situation, challenges and suggestions of the discipline of high-power fiber laser technology in China

Abstract: High-power fiber laser is a hot spot in the field of laser technology, and China has achieved rapid development and outstanding achievements in recent years. Learn from the text
From the perspective of the direction of science, the development process of this discipline in China is sorted out in four stages, from scientific research, education and teaching, academic exchanges, and industry response
This paper introduces the current situation of the discipline direction, summarizes the challenges for further development through in-depth comparative analysis, and puts forward countermeasures and suggestions.
Keywords: high power; fiber laser; discipline
CLC Number: TN2480
INTRODUCTION
Document Identifier Code: A              DOI：10.3788/IRLA20230071

January 2023, National Natural Science Foundation of China
The management personnel of the Ministry and relevant technical experts cooperated to publish the "National Natural Sciences
Analysis and prospect of the development of laser science and technology in China from the perspective of academic foundation》
In this paper, laser science in China is sorted out from the perspective of the National Natural Science Foundation of China
The current status and challenges of technology development [1]. The article introduces the National Natural Science Foundation
The section on the funding of key projects of the gold project states: "The hottest theme is hot
The words are 'fiber', 'high power', 'infrared', 'femtosecond'. High power is the most laser
One of the important core indicators, laser-related application fields are multifaceted
The increase in energy depends on higher power lasers. Fiber optics have a large size
The surface area / volume ratio, the heat dissipation performance is very superior, therefore, to optical fibers
As a gain medium, it is an ideal way to achieve high-power lasers."
This shows that high power is a research application hotspot, and fiber laser is the realization
An important way to high power.

In recent years, China has been in the scientific research of high-power fiber lasers
Remarkable achievements have been made, which stems from the many years of our country's use of high-power optical fibers
Profound accumulation in the direction of laser technology. The text is based on the literature [1].
On the basis of the discipline, from the perspective of the direction of the discipline, from scientific research, education and teaching
Review the process, analyze the current situation, and systematize the technical exchanges, industry applications, etc
Sort out the current problems and challenges, and the direction of the discipline
to make recommendations for development.

1 History
In the early days, fiber laser was mainly used as an information photonic device.
It is used in communication, sensing, imaging and other fields. In 1988, the invention of double-clad optical fiber [2], combined with the rapid development of semiconductor laser technology at that time, made it possible
The semiconductor laser cladding pumping method has been rapidly applied, and the fiber laser
The device has the possibility of becoming an energy photonic device, and the power of the fiber laser is obtained
to the point of rapid ascension [3−4]. The development of high-power fiber lasers in China is also
Based on double-clad fiber and semiconductor laser cladding pumping and other technologies, step by step
realized.
Systematically sort out the relevant published literature (including papers, conferences
discussions, news reports, scientific research projects, etc.), China's high-power fiber laser
The development of the discipline can be roughly divided into four stages:

(1) Accumulation stage (1990-1999). 80 years of the 20th century
In the past, the content of China's report on "fiber laser" is the same as the current one
The consensus on fiber laser is not the same, and "fiber" is used as "laser".
The transmission medium is the main one. Since about 1990, the country has begun to pay attention to
Research on fiber lasers with "optical fiber" as the medium of "laser" generation, Nankai University
Shanghai Institute of Optics and Fine Mechanics, Chinese Academy of Sciences (hereinafter referred to as "Shanghai Institute of Optics and Fine Mechanics").
Shanghai Institute of Optics and Mechanics, Chinese Academy of Sciences), Tianjin University and other units carried out related earlier
Research [5−9]. Although there are already related double-clad fiber lasers in the world
However, at that time, domestic research was mainly on the generation mechanism of lasers
, single-clad fibers are the mainstay, and double-clad fibers are not reported much. follow
With the continuous improvement of output power, the international double-clad fiber laser technology
The progress has attracted increasing attention from domestic researchers [10−11]. In 1997,
The joint research group of the University of Science and Technology of China and the Hong Kong University of Science and Technology has studied
The pump wavelength of the double-clad optical fiber developed by Tianjin Institute of Electronic Materials
and its spectral properties; In 1999, Wuhan Academy of Posts and Telecommunications reported on self-development
Laser performance of double-clad fibers. The successful development of domestic double-clad optical fiber has laid a good foundation for the start of high-power fiber lasers in China [12–13].

(2) Initial stage (1999-2009). Around 1999
It can be preliminarily regarded as the beginning of China's high-power fiber laser, which was issued in 1999
Table of "Cladding Pumped Fiber Lasers" is an earlier comprehensive introduction to the basics
Papers, on principles, key technologies, research progress, and development trends [14];
From 1999 to 2000, Fudan University and Fiberhome Communication Technology Co., Ltd. owned
Limited company cooperation, Nankai University and Tianjin Institute of Electronic Materials,
Shanghai Institute of Optics and Mechanics, Chinese Academy of Sciences, University of Science and Technology of China, and Wuhan Department of Posts and Telecommunications
The cooperation of the college has realized the laser delivery based on domestic double-clad fiber
[15−17]. In 2000, Academician Wang Zhijiang suggested the Shanghai Institute of Optics and Mechanics of the Chinese Academy of Sciences
Researcher Lou Qihong (domestic research on high-power and high-brightness fiber lasers
pioneer) to carry out fiber laser research [18], and Professor Lou led the research group in
In 2002, it achieved a power output of 4.9 watts [19]; In the same year, Nankai University Newspaper
The output power is up to the watt level of the all-fiber structure double-clad fiber excitation
Optical apparatus [20], related research has been awarded the key project of the National Natural Science Foundation of China
[21]. After that, the technical level of China's high-power fiber laser
It has made rapid improvements, the Shanghai Institute of Optics and Mechanics of the Chinese Academy of Sciences, and the West of the Chinese Academy of Sciences
An Institute of Optics and Fine Mechanics, Changchun Optical Precision Machine, Chinese Academy of Sciences
Research on laser fusion at the Institute of Mechanical and Physics and the China Academy of Engineering Physics
Center, Tsinghua University, Nankai University, Beijing Jiaotong University, National Defense Department
Technical universities and other units have published more research papers; Around 2007,
Ordnance Equipment Research Institute, Shanghai Institute of Optics and Mechanics, Chinese Academy of Sciences, North China Optoelectronics
The Institute of Technology, Tsinghua University and many other units have realized the single-fiber laser thousand
Watt-level output [22−25].

It is worth noting that the kilowatt-class lasers that were realized at that time were all used
It is a spatial structure, and compared with the all-fiber structure that is widely used later, it is real
The usability is relatively poor, and the output power has not been further improved after that
In 2009, the maximum output power was still in the kilowatt range. And from
From 2004 to 2009, the use of all-optical fiber structure by international counterparts has been realized
The output power of single-mode lasers has leaped from kilowatts to 10,000 watts [3,26]. albeit
In this way, at this stage, Huazhong University of Science and Technology, Shanghai transmission line research
Tianjin Institute of Electronic Materials, Fiberhome Communication Co., Ltd. and other units
The development of laser optical fiber has been carried out, and Tsinghua University and other units have carried out optical fiber stimulation
Theoretical research on optical mode analysis, Zhuhai optical library, Shenzhen Guangyue, Shenzhen
Langguang, Beijing Kaplin and other enterprises carry out passive devices and semiconductor pumping
Source and other key components development, Xi'an Institute of Optics and Fine Mechanics, Chinese Academy of Sciences
Research institutes and other units carry out research on high-power all-fiber lasers, Wuhan Rui
Branch Fiber Laser Technology Co., Ltd. and other units to carry out high-power light
The development of the fiber laser machine is a more scientific and reasonable layout and development for the follow-up
Reserves were made.

(3) Rapid improvement stage (2010-2017). Facing the application
Demand and technology gap, around 2010, China's high-power fiber laser
The discipline direction has entered a stage of rapid improvement, and all research units have combined the application needs
Seeking and developing reality, the research content has been scientifically laid out and scientifically studied
The objectives and content of the study are more reasonable. Shanghai Institute of Optics and Mechanics, Chinese Academy of Sciences,
Tsinghua University, National University of Defense Technology and other units focus on fiber grating and pumping
All-fiber structures such as beam combiners, pump/signal beam combiners, and fiber end caps are required
High-performance passive components to carry out research, Shanghai Transmission Line Research Institute,
Laser fusion at Tianjin Institute of Electronic Materials and China Academy of Engineering Physics
Center, Shanghai Institute of Optics and Mechanics, Chinese Academy of Sciences, Beijing University of Technology, National Defense
University of Science and Technology, Huazhong University of Science and Technology, South China University of Technology and other units were launched
Or make greater efforts to carry out the development of laser fibers, Wuhan Ruike fiber laser
Technology Co., Ltd., Shenzhen Chuangxin and other units are committed to the device and integration
localization of machines; At the same time, the fine division of labor and collaborative innovation of domestic scientific research
The characteristics are becoming more and more prominent, high-power single-frequency and narrow linewidth fiber laser, high power
Rate broadband/supercontinuum fiber laser, high power Raman fiber laser, high
Representative research directions such as power fiber laser coherent synthesis have been obtained
As a result, it has achieved a good international influence [27−35].

At this stage, domestic counterparts pay more attention to education, teaching and academic communication
activities such as streams [36−40] have promoted the development of disciplines in many aspects.
In 2010, the University of Science and Technology of China Press published "High Power Optical Fiber
Lasers and Their Applications"; 2011, Shanghai Photonics, Chinese Academy of Sciences
The institute and other units started to hold the "advanced training course on fiber laser"; 2012
In the year, the Optoelectronic Special Committee of the Chinese Society of Astronautics and the National University of Defense Technology
The School of Electrical Science and Engineering and other units jointly organized the "International High Power Optical Fiber
Laser Technology Research and Application". Through this stage of the cloth
Bureau, China's high-power fiber laser discipline has made a series of important achievements
Results: The 22nd National Laser Academic Conference held in 2016
There are 2 conference reports closely related to high-power fiber lasers (Newspaper
The names of the reports are "The Present and Future of Fiber Laser" and "High-Power Light".
Research on the nonlinearity of fiber lasers"), and the report is announced and introduced
The experimental results of single-fiber fiber laser with 10,000-watt high-power output are reviewed
It is hoped that China's research in this field has once again reached the international advanced level;
In February 2017, China Laser released "High-power fiber laser technology
"Technology", which contains 21 excellent papers, focuses on China's Research Results.

(4) Stable development stage (2018 to present). In recent years, our country
The discipline of high-power fiber laser has entered a stage of rapid development. One
In terms of laser fibers, the performance of functional components continues to improve, and functional fibers
The integrated development of high-power (device) and high-power fiber (device) functionalization [41] provides diversification for the development and performance improvement of laser machines
Selected, laid a good "hardware" foundation, and drove the laser combination
Breakthrough in laser application; On the other hand, fiber laser is physical, non-physical
Linear effect and mode instability effect inhibition and other basic theoretical research
Some progress has been made [42−43] and software has been continuously updated into fiber laser design
It provides a good solution for the design and development of high-power fiber lasers
"Software" basics.
In addition, through the study of materials science and engineering, computer science and technology
The intersection of technology, control science and engineering and other disciplines in laser design and control
Innovative research achievements have also been made in production, measurement, and application
fruit [44]. Judging from the publicly reported literature, conventional high-power lasers and multi-mode
The output power of high-power lasers exceeds 20,000 watts and 100,000 watts, respectively
level [45-50], reaching the international advanced level. High speed of high-power fiber lasers
The development has injected strong kinetic energy into "laser manufacturing" and "additive manufacturing".
It has entered the development of advanced manufacturing and other fields in China.
It should be noted that the above four stages are only based on the generation
A general distinction is made in the epigraphic literature, and does not have a broad sense of the general Adaptability.

2 Status
According to the "Catalogue of Graduate Education Disciplines", high-power optical fiber excitation
Light belongs to the first-level discipline of "optical engineering"; In accordance with the People's Republic of China
National Standard Discipline Classification and Code", high-power fiber laser belongs to the "electrical
Sub, communication and automatic control technology "below" optoelectronics and laser technology
technology". Although it is a relatively "small" and "narrow" discipline direction, it has been
After forming a relatively clear and sustainable growth and development of the "academic community",
And maintain benign interaction with other disciplines, scientific research,
Education and teaching, academic exchanges, industry applications and other aspects are all improving Develop.

(1) Scientific research. Our country has formed a relatively stable one
Scientific research funding system: Since the 13th Five-Year Plan, the National Key R&D Program has been stimulated
Optical Manufacturing and Additive Manufacturing", "New Displays and Strategic Electronic Materials"
and other special projects have given stable support to the research of high-power fiber lasers;
Since the beginning of the 21st century, the National Natural Science Foundation of China (F0506 and other codes) has also passed
A variety of scientific research projects and talents such as major, key, general, and youth
and other projects fully support high-power fiber laser research. Recent
To come, the domestic scientific research force specializing in high-power fiber laser construction hoof
Steady pace, improving day by day, output (including academic papers, industrial products
etc.), there are more units such as Shanghai Institute of Optics and Mechanics, Chinese Academy of Sciences/China Section
Xi'an Institute of Optics and Fine Mechanics/Anhui Institute of Optics and Fine Mechanics, Chinese Academy of Sciences, China Academy of Engineering Physics, Laser Fusion Research
Center/Institute of Applied Electronics, Tsinghua University, Tianjin University, Beijing Institute of Technology
Huazhong University of Science and Technology, South China University of Technology, University of Electronic Science and Technology
Nanjing University of Science and Technology, Jilin University, National University of Defense Technology, Wuhan
Ruike Fiber Laser Technology Co., Ltd., Shenzhen Chuangxin, Shenzhen Jie
Pute and so on, covering scientific research institutes, colleges and universities, high-tech enterprises
and other innovative subjects. With the support of scientific research projects, various innovative subjects are continuous
Produce high-level results. Search on the subject of "high-power fiber laser".
Web of Science database, published by 5 700 papers in China
The remainder (as of January 2023). The leading (advanced) technical indicators are:
High-power single-frequency lasers, high-power narrow linewidth lasers, laser coherent combination
Laser spectral synthesis, high-power Raman laser, high-power supercontinuous
Spectral laser, high-power superfluorescence laser, high-power visible laser, etc.

(2) Education and teaching. China in the discipline of high-power fiber laser
The direction has formed a diversified education and teaching method to promote talents
Improvement of the scale and quality of cultivation. Some colleges and universities have opened majors
courses, such as the School of Frontier Interdisciplinary Studies of the National University of Defense Technology, have been offered
Fundamentals of Fiber Laser; Chinese lasers
The "advanced training course on fiber laser" held by magazines and other units is attractive
Continued expansion. In recent years, with the development of information technology, Chinese optics
Passed by the Society, the Chinese Optical Engineering Society, and the China Laser Magazine
"Photonics Open Course", "Cloud Light Classroom", "Optical Frontier Online" and other networks
The way of online courses further promotes the dissemination of knowledge, "Photonics is open."
The total number of viewers of the course "High Power Fiber Laser" has passed
Ten thousand. The Institute of Software of the Chinese Academy of Sciences and the National University of Defense Technology have a frontier relationship
The Seefiberlaser software was jointly developed by the Fork Discipline College and other units[51],
It has built a "bridge" from basic theory to laser development, which can guide the not
Personnel at the same stage (beginners, advanced researchers) design and prepare stimuli Lighter.

(3) Academic exchanges. China's scientific and technological journals and academic conferences are
The academic exchange of high-power fiber laser peers provides a high-end platform.
According to the statistics of CNKI, "Chinese Laser", "Acta Optica Sinica", "Physics
Newspaper", "Infrared and Laser Engineering", "Strong Laser and Particle Beam" and other Chinese
Journals and Chinese Optics Letters, Photonics Research,
High Power Laser Science and Engineering
The journal has published a large number of high-quality research papers, such as "China Laser", "Red".
Journal of Surgery and Laser Engineering has been further developed by publishing special issues [40,52].
Step to promote academic exchanges among small peers. China Optical Conference, National Laser
Academic Conference, Laser and Optoelectronics Conference, National Laser Technology and Industry
Industry Development Conference, Applied Optics and Photonics Conference (AOPC), Conference on Information Optics and Pho
High-level academic conferences such as tonics (CIOP) have relevant topics
(Special Topic). In addition, since 2019, it has been hosted by the Chinese Optical Engineering Society
Specialized Advanced Fiber Laser (AFL) research
The meeting has been selected as the guide to high-level academic conferences of the China Association for Science and Technology
It is a high-level academic conference recognized by peers at home and abroad. In addition, in
Photonics West (PW)、 Advanced Solid State Laser
(ASSL), CLEO-PR and other high-level international conferences, China also has specialists
Home serves on the Program Committee and other bodies, these meetings and domestic units are the masters
Organized related conferences (such as AFL, etc.) together provide China with the world A platform for communication.

(4) Industry application. In recent years, high-power fiber lasers
The rapid development of industry applications has formed materials, components, lasers, and lasers
The chain of the system is complete, according to the "China Laser Industry Development Report",
In 2020 and 2021, the output value of the fiber laser industry has reached respectively
to 9.42 billion yuan and 12.48 billion yuan [53]; It is expected to reach 13.8 billion in 2022
Yuan [54]. High average power CW waves (including quasi-continuous, long pulses
The main application fields of fiber laser are cutting, welding, and 3D playing
In printing, cleaning and other industries, high average power ultrashort pulse fiber lasers have also been used in thermal imagers, spot analyzers, beam quality measuring instruments and spectrometers
and other equipment, the proportion of domestic equipment is not high; High-power fiber laser has been developed
Cutting, face treatment, welding, coating and other processes in the process are cured It also needs to be strengthened.

(2) There are almost no original theories. Research on high-power fiber lasers,
Professor Agrawal's book "Nonlinear Fiber Optics" basically covers it
The book has been published with the classical theoretical tools and methods required6
Edition [59], the Chinese version has also been updated to the 5th edition [60], introductory stage and advanced level
It is suitable for anyone in the R&D phase. In recent years, with the study of not
In depth, some new theories have been developed in the direction of high-power fiber lasers
e.g., mode instability, nonlinear effects in multimode fibers,
etc., which have not yet been included in this book. However, the theoretical basic source of originality
From Jena University in Germany, Cornell University in the United States, and the Russian Academy of Sciences
Beria Branch, Aston University, UK, etc. [61−65]. It is worth pointing out
Yes, China is in the aspects of optical cavity time-frequency dynamics and pulsed soliton dynamics
Breakthroughs have been made in basic research and have been experimentally verified [66−70], which is expected
In the future, more forces can be invested in basic research to form a Chinese atmosphere The school of theory.

(3) Monographs and textbooks need to be strengthened. In recent years, Springer, Wiley,
CRC and other publishing institutions have published high-level academic monographs [71−75].
Under the domestic progress in recent years is significantly insufficient, with research and application of water
The mismatch between the development of the flat has led to the case of domestic teachers and students and enterprise R&D personnel
The first reference books are mainly imported original books or photocopies. furthermore
Although significant progress has been made in the areas of courses (training courses), etc., it is not reported that
At present, there are no special textbooks in China, graduate and introductory stage
of researchers "enlighten knowledge" mainly by reading relevant classics
Review articles [76−77].

(4) Peer communication is insufficient. With the deepening of research and application
The promotion of domestic scientific and technological journals and academic conferences is synchronized with the construction and development,
It provides a good communication for the personnel in the direction of high-power fiber laser
platform, but the phenomenon of separation of "research" and "application" is more obvious in the same industry
Communication is inadequate. For example, at the National Laser Academic Conference, Laser and Light
Electronics Conference (LTO), AOPC and other comprehensive classes involving fiber lasers
At the academic conference, the participating units are based on the research and development of fiber lasers in colleges and universities
mainly scientific research institutes; In the national laser processing academic conference, it involves optical fibers
At the academic conference on the application of lasers, the participants are enterprises and application researchers
Research institutions are the mainstay, and universities and research institutes participating in the research and development of fiber lasers
There are very few of them. In contrast, it can be noted that in order to Photonics
West's Fiber Laser Branch, etc.
Universities, research institutes, enterprises, national laboratories and other innovative entities have actively participated, and many high-quality original achievements have been made by IPG
Published by Photonics, Northrop Grumman, et al. [78−80].

4 Recommendations
After years of construction and development, China has a strong presence in high-power fiber lasers
Gratifying results have been achieved in the direction of the section. But objective analysis, with international counterparts
Compared to this, we are still in the stage of "running along" and local "running along", with application
Compared with the demand, the current level of technology is still obviously insufficient. How to be more
Rational allocation of scientific and technological resources, more effective stimulation of innovation vitality, for the sake of science
It is one that a technological power, a manufacturing power, a aerospace power, etc., have made contributions to the industry
A topic that requires in-depth analysis and judgment. Comprehensive national planning
policy, the generation and evolution of new scientific research paradigms, and the construction of "double first-class".
Combining the existing foundation and challenges of the discipline direction to the future
The development makes the following recommendations:

(1) Scientific research. Encourage multidisciplinary interdisciplinary and originality
Explore, and strive to be in laser fiber materials, fiber processing equipment, laser properties
It can achieve new results in terms of measurement equipment, etc.; By setting up multiple types
of major projects, guide superior units to carry out intelligent research. In the 10,000-watt range
Single-mode laser, 100,000-watt multi-mode laser in industry, national defense and other fields
Application demand drives scientific research and promotes industry applications. In particular, roots
According to the application performance improvement and future development needs, high-power fiber lasers
The development has shown that "the laser pulse characteristics are controllable and the laser spectral characteristics are presented."
controllable, spatial mode characteristics controllable" [26], laser materials are needed
Researchers in the fields of material, laser physics and information technology
with the effort.

(2) Education and teaching. Increase professional training courses and online disclosure
We actively introduce high-level academics such as CLEO and ASSL
Short courses taught by international experts at conferences; Actively apply
"Virtual Teaching and Research Departments" to promote the sharing of educational resources; Encourage high-level subjects
The research results are incorporated into classrooms and teaching materials, and laser technology and artificial intelligence are closely followed
The "two-way empowerment" capability of energy technology [81] to create high-quality teaching materials and create excellent ones
quality courses to promote the integration of science and education. Compare with IPG Photonics and other technologies in the United States
The scale of human resources of the leading units, strengthening education and teaching, further
Expanding the professional research team is a matter that needs to be paid attention to in the development of the industry.
(3) Academic exchanges. Guide researchers to conclude good research
If it is published in domestic journals, especially Chinese journals, it will be organized in a timely manner according to the situation
Various types of special issues (special issues) focus on domestic research results; Cohesion building
Set up a high-level professional international academic conference represented by AFL, take the initiative
Set up forums or design specializations at high-level comprehensive academic conferences in China
Encourage high-quality interaction between personnel of different types of innovation subjects.