First, laser technology background
Laser technology, since its birth in the middle of the 20th century, has become one of the cornerstones of modern science and technology, and
its development background is rich and far-reaching. In 1960, the advent of the first laser marked the beginning of a new era, Maiman used
ruby crystals to successfully produce coherent light, this new type of light source has unprecedented monochromatic, coherent, and
directional, for scientific research and technical applications to open up a new world. After entering the 21st century, with the development of
semiconductor pumping technology, fiber laser technology, and ultrafast laser technology, laser technology has ushered in a new leap.
Semiconductor pumping technology improves the electro-optical conversion efficiency of laser and reduces the manufacturing cost. Fiber
lasers are the best choice for industrial processing because of their high power, high stability, and compact structure. Ultrafast lasers, with their
ultra-short pulse characteristics, show great potential in micro and nano processing and biomedical fields. At present, laser technology is
developing in the direction of higher power, higher precision, and wider application.
With the rapid development of fiber laser technology, the output power, beam quality, and electro-optical efficiency of the laser are continuously
improved, which provides a technical basis for the research and development of high-power green lasers. The development of nonlinear
optical frequency doubling technology makes it possible to convert from infrared fiber laser to green laser and improves the output power of
green laser. In the field of industrial processing, high-power laser equipment plays an important role in the cutting, welding, marking, and
measurement of aerospace, automobile manufacturing, shipbuilding, and other fields; In the field of medical applications, the accuracy and
control of lasers makes them widely used in eye surgery, skin treatments, and other medical procedures. Laser technology has penetrated
every aspect of daily life, from industrial manufacturing to artistic creation to scientific research. With the advancement of technology, the
development of high-power lasers has significantly improved the industrial processing capacity of lasers.
Second, high power, short wavelength laser application development and advantages
The development of high-power green lasers has attracted much attention. Because of its continuous operation mode and waveguide
structure, continuous fiber laser has the advantages of uniform output laser energy, high gain, high conversion efficiency, ultra-high power
output, good beam quality, easy-to-achieve single-mode output, and stable performance.
The principle of laser and material interaction is complex and diverse, and different laser parameters (such as wavelength, power, pulse width,
etc.) and material characteristics will lead to different interaction effects. The results of these interactions are widely used in the application of
laser technology, such as material processing, medical treatment, scientific research, etc. Figure 1 shows the absorption rate of different
materials for different wavelengths of laser light. It can be seen that the absorption curves of different materials for different wavelengths of
laser is different. The laser energy absorbed by the material during processing can be converted into heat energy, causing the local
the temperature of the material to rise. This thermal effect is important in processes such as laser cutting, welding, and heat treatment, causing
the material to undergo phase transitions such as melting, evaporation, or sublimation.
Copper material is one of the most widely used metal materials in the world. Under normal temperature conditions, as shown in Figure 2, the
the absorption rate of copper material for a 1m band laser is less than 5%, while the absorption rate of 532nm green light can reach 40%,
which is equivalent to 8 times that of a near-infrared band laser. Copper is widely used in lithium, microelectronics, and other industries, the
the current industry is the most used 1m band near-infrared laser, due to the low absorption rate of copper on 1m band laser will appear in the
process of low efficiency, bubbles, spatter, and other problems, and green laser for cutting or welding copper and other materials effect is
much better than the near-infrared laser effect. Therefore, the realization of high power and high efficiency continuous green light output has
become one of the research hotspots of lasers.
An important application of green lasers is 3D printing technology. In the field of metal 3D printing, green lasers can improve the print quality
and achieve 3D printing of complex structures of pure copper materials.
The application of a single-mode continuous green fiber laser as a light source in printing pure copper is a relatively new field of technology
that takes advantage of the beam properties of green lasers to overcome the challenges encountered by traditional laser technology in dealing
with highly reflective materials. Since the absorption rate of pure copper to green light is much higher than that of near-infrared light, the green
laser is more effective in the processing of copper materials. On the other hand, the beam produced by a single-mode laser has high quality
and consistency, which is essential for precision machining, especially when printing pure copper, to ensure the fineness and consistency of
the printing process.
In the development of short-wavelength lasers, ultraviolet (UV) lasers and blue lasers have attracted much attention because of their unique
application characteristics. Due to the short wavelength of the ultraviolet laser, the purity and optical characteristics of the material are
extremely high, it is difficult to find a material that can withstand high-power ultraviolet laser and the ultraviolet laser that exceeds 100 watts on
the market is rare. Although there are manufacturers to achieve kilowatt-level power output, before the fiber beam, the blue laser needs to
carry out space beam, this process has strict requirements for the quality, stability, and power distribution of the laser beam, compared with the
fiber laser, the beam quality of the blue laser is poor, which limits its performance in some precision machining applications.
On the other hand, through the efforts of researchers in various countries, commercial green lasers have made great progress in recent years.
The TruDisk 3022, a high-power continuous green disc laser launched by Germany's TRUMPF Group in 2021, can provide the highest output
power of multi-mode 3kW, which is the highest power in the current green laser series, demonstrating its application advantages in copper
welding, but its price is very expensive. The United States IPG company launched the world's first kilowatt-level single-mode nanosecond
pulse green laser GLPN-1000 in 2022, which can provide an average power of up to 1kW, the whole machine is small, and the electrooptic
conversion efficiency is as high as 25%, which has attracted wide attention from the industry.
The world's first near-single-mode 2 kW continuous green laser
According to the latest report of market research firm Optech Consulting, the global laser system market for material processing is estimated to
be $23.5 billion in 2023, an increase of 4% year-on-year. With the development of high-end manufacturing, the demand for high-power green
lasers are growing.
Shenzhen Gongda Laser, mainly engaged in "advanced short-wavelength fiber laser" and "laser precision processing solutions" R & D,
production and Sales is a laser company focusing on the research and development, production, and application of medium-high power short-
wavelength (green and ultraviolet) all-fiber lasers. Following the 500W single-mode green laser launched in 2022 and the 1000W single-mode
and 3000W multi-mode continuous green laser launched in 2023, the new launch of the near-single-mode green fiber laser with a maximum
output power of 2kW has been tested and verified by customers in terminal-related industries. Gongda Laser is the world's first manufacturer
capable of providing 2 kilowatts of nearly single-mode continuous green laser products.
Iv. Conclusion and prospect
Gongda Laser's newly launched near-single-mode 2 kW continuous green laser is the world's highest average power quasi-single-mode
continuous fiber green laser. The launch of the product provides more sufficient energy for the processing of high inverse materials and the
near-single-mode output ensures the high quality and consistency of the laser beam, which is expected to bring higher welding quality, higher
efficiency, and deeper penetration for the processing of thick copper materials. The structure of all-fiber fundamental frequency and out-of-
cavity frequency doubling provides a high degree of stability and reliability while ensuring the compact and easy integration of the laser. With
the continuous progress of technology and the continuous maturity of the market, we have reason to believe that high-power fiber green lasers
will bring more possibilities to society.
The high-power green light has obvious advantages in copper precision welding, especially in electrically controlled IGBT and flat wire motor
welding, with a small thermal effect, small splash, stable tension, and high yield. In addition to high anti-metal materials such as copper
welding has outstanding physical characteristics and advantages; It also has great application potential in 3D printing of high-precision and
high-efficiency copper materials.
In the future, we will continue to work hard to develop more innovative technologies to further improve the power, efficiency, and reliability of
lasers, while reducing costs, matching more important application scenarios, and contributing to the upgrading of global high-end
manufacturing.