Cutting and joining technology is an important technological cluster in the industrial system.
Laser processing is one of the brightest jewels of this technological cluster.
Especially in today's Industry 4.0 and smart manufacturing, some people even consider laser processing to be the most natural link with smart manufacturing among all cutting and joining technologies.
So let's delve into this whole topic of the laser industry today and systematically summarize the development history of the fiber laser industry.
The history of industry and technology is an important reference and background that should not be missed by those who later walk alone in industry and entrepreneurship.
First, let's review and summarize the basics of lasers .
The laser has been called “the brightest light, the fastest knife, the most accurate ruler.”
The English name “Laser”, namely Light Amplification by Stimulated Emission of Radiation (LASER), is considered one of the greatest scientific and technological inventions of the 20th century.
The scientific principle of laser “Stimulated Emission of Radiation” was proposed by Albert Einstein in 1917, the theory of “spontaneous and stimulated emission” is considered the physics of modern laser technology based.
Einstein pointed out that a particle at high energy level E2, when the frequency of V = (E2-E1)/h incident photon (h is Planck's constant), the particle will, with some probability, quickly jump from the energy level E2 energy to E1 energy level, when radiating a foreign photon with the same frequency, phase, polarization state and propagation direction as the photons, this is called excitation radiation.
Do you understand what this means?
One photon is exactly the same as another. What will these two photons do next?
That's right, these two looked for other particles to fire, making four in total.
The process is like a chain reaction of a nuclear explosion, with the number of photons increasing rapidly, equivalent to the original light signal being amplified.
The laser was only manufactured in 1960, five years after Einstein's death, when he proposed the theory of “spontaneous and stimulated emission”.
Why did it take so long?
Because of the “stimulated absorption” proposed in Einstein’s article.
A photon could hit a particle at the E1 energy level, transform it to an E2 energy level, disappear on its own, and the so-called chain reaction would be lost.
For materials in general, the stimulated absorbed particles are more than the excited particles (more E1 than E2 at lower energy levels), so the intensity of the light passing through will not be amplified, but reduced.
To produce a laser, the key condition is that “particle number reversal”, high-energy particles are more than low-energy particles.
But it's not that difficult, looking back to the 1930s, physicists managed to do it.
But scientists didn't think about doing this because they didn't have enough integration between optical theory and technology in the 1930s, after all, there were many other significant discoveries.
This makes the invention of the laser a bit complicated. It was the “Maser” (microwave amplifier) that was developed first and then the “Laser” was created.
The photo above is a classic, with Townes on the left, and his student Gordon on the right, in front of a Maser (microwave exciter).
Note that the one in the background on the far right is a Chinese man, Wang Tianliang, who later returned to China and founded the Spectroscopy Laboratory at the Wuhan Institute of Mathematical Physics.
This means that Townes is the creator of the Maser and is also known by some as the inventor of the laser.
However, scientists also fight the position of the inventor of the laser.
Townes, who worked at Bell Labs during World War II, worked on the principles and design of radar.
As a result, Townes became interested in creating microwaves and molecular spectroscopy (radar uses microwaves, and now cell phones, Wi-Fi, and other wireless communications use microwaves).
After World War II, Townes moved to Columbia University, and it was for building the world's first microwave exciter (Maser) that Townes won the Nobel Prize in Physics in 1964.
Naturally, Townes wanted to build a short-wavelength microwave exciter (Maser).
If step by step it is, millimeter wave, submillimeter wave, far infrared, mid infrared, near infrared, visible light, even ultraviolet light.
Townes has also been working in this direction.
However, difficulties were encountered with millimeter and submillimeter waves, and it was difficult to succeed anyway, so the plan was to give up for now and turn to visible light first, which could be easy and meaningful.
Together with his brother-in-law, Sholoh, Townes developed a theory on how to implement this microwave exciter (Maser) in the visible range, which has been very influential.
They directed the light emitted by a neon lamp onto a rare earth crystal, and the crystal emitted a bright, ever-accumulating light.
In fact, the visible light microwave exciter (Maser), is the Laser.
This set the stage for the invention of the Laser.
At this time a young man, namely Mayman, came off the road, who became very interested, and also contacted Townes to create the laser.
Unfortunately, he was not accepted into the revolutionary team. However, Mayman opened his own kitchen and manufactured the laser in 1960.
The image above shows a ruby laser made by Mayman.
Mayman uses a high-intensity flash tube to excite the ruby. The key here is to have an “optical resonance cavity,” where light passes through the crystal at modest magnification, but if a reflector is attached to both ends and the light is constantly magnified back and forth, it's incredible.
A piece of the reflector, with a little less silver coating, leaks some of the light and out comes the familiar excellent unidirectional laser.
Merman is one of the fastest peach pickers.
Townes and others were certainly not very convinced and Townes won the Nobel Prize in 1964 and his level was recognized.
Thus, the seeds of the controversy over who was the inventor of the laser were planted.
Just as Edison fought Tesla and Westinghouse over electric current, there is no shortage of fights and rivalries in the scientific community.
And it is these rivalries that have driven human progress.
In the 1960s, when the world was divided into two camps, socialism versus capitalism, the laser community naturally would not develop without the Soviet Union.
In 1964, for the laser, the two Soviet physicists who won the Nobel Prize at the same time as Townes – Nikolai Basov and Alexander Prokhorov – received the prize.
We all know the story of Soviet leader Khrushchev taking off his shoes and banging the table at the 1960 UNGA meeting.
We should know: behind the strength and dominance of politicians lies an all-encompassing national power.
At that time, the Soviet Union was the best in the world not only in nuclear weapons and aerospace, but also in basic science such as lasers.
This was Khrushchev's confidence.
Soviet physicist Basov proposed semiconductor lasers that developed the later artifact: the fiber laser.
Basov (right) and Prokhorov (left) take Townes (middle) to visit his laboratory
Like Townes' team, Basov and Prokhorov also created a “Maser” in 1955 – a microwave exciter using an ammonia molecular beam, and naturally thought about lasers.
Basov's contribution is that he published a paper in 1958 and presented the idea of using semiconductors to make lasers (the theoretical description of “particle number inversion” in semiconductors), and in 1961 he published “carrier injection” PN junctions. . Article, and in 1963 created a PN junction semiconductor laser (the Americans first created it according to the principle he proposed).
Semiconductor lasers are not as famous as the ruby lasers that appear in textbooks, but experts are clearly aware of the theoretical significance of semiconductor lasers and the potential is much greater, so the three-way tie for the Nobel Prize went to two Soviets and one. American.
The advantages of semiconductor lasers are numerous:
- Electrons directly into photons, with an electro-optical conversion efficiency of over 50%, far superior to other types of lasers.
- Longer lifespan of over 100,000 hours, much longer than other types;
- Semiconductors can also modulate the output, which other types cannot do.
- Small, light and economical, semiconductors are cheaper than materials like rubies.
The laser is a rare technology that became immediately practical when it was invented and used for surgery in 1961.
Because the characteristics of the laser are very striking, all coherence photons are particularly good, pointing in one direction, the energy applied to a point can be a million times brighter than the sun.
A laser with higher power can be used for cutting and processing.
There are many uses for cutting, welding, measuring and marking. It is used in numerous industries such as communications, industrial processing, medical treatment and beauty, constantly replacing traditional processes.
At this point, we have to mention China.
This year marks the 40th anniversary of China's reform and opening up, and 40 years of achievements are not a castle in the air from scratch.
New China laid a complete industrial base and investment in basic sciences in the first 30 years, which is the basis of economic reform and take-off in the last 40 years.
One year after the construction of the laser in the United States, in the fall of 1961, Wang Zhijiang, a young researcher at the Changchun Institute of Optics and Mechanics, built China's first laser in 1961 under the guidance of his teacher, Academician Wang Daheng.
The Father of Chinese Optics – Academician Wang Daheng
The Father of Chinese Lasers – Wang Zhijiang and Ruby Laser
China's first laser is available, but the name is not yet available.
Just like a young couple who have given birth to their first child, they always hope to find a respectable elder to name it.
In October 1964, the editorial department of the magazine “Optical Stimulated Emission Intelligence” (formerly known as “Light Quantum Amplification Special”) sponsored by the Changchun Institute of Optics and Mechanics of the Chinese Academy of Sciences wrote to Qian Xuesen, asking him to give the LASER a Chinese name and Qian Xuesen suggested a Chinese name for “激光”.
In December of the same year, Shanghai held the 3rd Academic Conference on Optical Quantum Amplifiers, chaired by Yan Jici. After discussion, Qian Xuesen's proposal was formally adopted and the English abbreviation LASER for “light amplification by stimulated emission of radiation” was officially translated as “激光”.
Later, the magazine “Optical Stimulated Emission Intelligence” also changed its name to “Laser Intelligence”.
The development of science and technology follows a step-by-step concept from the formulation of basic concepts, to the establishment of basic theories, to the emergence of laboratory products.
In fact, only after it is industrialized will it be able to serve humanity and be able to rejuvenate itself.
This is the case with laser technology.
In the industrial market, the first industrial lasers used for material processing were mainly gas lasers and crystal lasers.
Gas laser, the typical representative is CO 2 laser.
The representative of crystal laser is YAG laser, YAG refers to yttrium aluminum garnet with addition of neodymium or ytterbium.
Today, Rofin Laser 2 's CO plate laser still has a large market share.
The CO2 laser machine uses CO2 as the working material to generate laser radiation, and the auxiliary gases nitrogen and helium are also loaded into the discharge tube.
When a high voltage is applied to the electrode, a light discharge is generated in the discharge tube, causing gas molecules to release laser light, and the energy is amplified to form a laser beam.
The YAG laser needs to use a krypton or xenon tube as a “pump lamp” to emit light that shines on the Nd:YAG crystal to generate laser light.
The emission spectrum of the pump lamp is a broadband continuous spectrum. Only a few spectral peaks are absorbed by Nd ions, and most of the unabsorbed spectral energy is converted into thermal energy, so the energy utilization rate is low.
CO 2 and YAG lasers have several shortcomings, but each also has its own advantages.
For example, the high-power laser produced is still very useful in industry.
The semiconductor laser has many advantages, but it has a fatal weakness: the quality of the laser light emitted is not good!
The output beam of the crystal laser is of high quality and has high temporal and spatial coherence. It claims to emit a laser beam to the Moon with a spot just 2 kilometers away.
The spectral linewidth and beam divergence angle of semiconductor lasers are several orders of magnitude greater than those of crystal lasers.
Therefore, early semiconductor lasers are generally used as pump light sources. For example, let the semiconductor laser be the bomb of the crystal laser and combine the advantages of the two.
The light source emitted by the semiconductor laser, after being “optimized” by the crystal laser, forms a high-quality beam and then emits it.
For example, the laser disc developed by TRUMPF followed this path.
TruDisk series disk lasers have the advantages of solid-state lasers and diode lasers.
Its disc guarantees the beam quality of the solid-state laser and also has the high energy and high efficiency of the diode laser as a pump source.
Speaking of which, I will compare the basic performance of four common industrial lasers (including the current protagonist fiber laser).
The all-encompassing power of fiber lasers is truly glamorous and impressive.
Table 1 Comparison of basic performance of 4 common industrial lasers
| Item | CO2 laser | YAG laser | Disk laser | fiber laser |
|---|---|---|---|---|
| Photoelectric Conversion Efficiency | 10% | 3% | 15% | 30% |
| Maximum output power | 20KW | 6KW | 8KW | 50 kW |
| BPP beam quality (4/5kW) | 6 | 25 | 8 | 2.5 |
| Diode Pump Lifespan | 5000H | 1000H | 10000H | 100000H |
| Operation and maintenance cost (4/5kW) | 20RMB/H | 35RMB/H | 8RMB/H | 2RMB/H |
There are often examples in industry.
The old generation of products cultivates the market, the process is changed, and then the new generation of products achieves efficiency improvements.
Fiber lasers emerged in this scenario to improve efficiency.
With the invention of the fiber laser and its launch on the market, some people doubled their value and became famous.
This is the so-called technical tuyere, and the first person who made this tuyere and sat on it was the Russian Valentin Gapontsev.
Valentin Gapontsev
Why does Gapenchev make a tuyere and sit on it?
Gapenchev was born in 1939. He is a senior scientist in the field of laser materials physics and head of the Radio Engineering and Electronic Science Research Laboratory of the Soviet Academy of Sciences. He has authentic Soviet technical training.
The Soviet Union and the Russians after disintegration seem to have difficulty managing business, but Gapenchev will do!
In the 1990s, when the Soviet Union disintegrated, the entire economy began to suffer a devastating blow and even disintegrated. The reason cowboys are cowboys is that they can always escape the traps of history.
Given that the objective of fighting for socialism for 50 years disappeared with the disintegration of the Soviet Union, Nagapenchev will have to face a new historical environment and a new historical process.
In 1990, he founded IPG Photonics.
In 2006, it was listed on Nasdaq (IPGP). In 2017, revenue was 1.4 billion US dollars and the current market value is 6 billion US dollars. It is the best-known fiber laser company in the industry.
IPG is headquartered in Massachusetts, with factories in the United States, Germany, Russia and Italy.
Gapenchev owns almost half of IPG's shares and is a billionaire, although he is still chairman and CEO of the company's board of directors at the age of 79.
In 2009, Gapenchev accompanied President Medvedev and Transport Minister Sokolov to visit IPG's production base in Russia
In 2009, Gapenchev received the Arthur Scholo Award from the American Laser Association, which is industry recognition for his academic achievements.
In 2010, Gapenchev won the Russian National Science and Technology Prize, the highest honor for Russian science and technology.
In fact, Gapenchev holds dual citizenship of the United States and Russia.
It can be said that he was a genius scientist who skillfully combined the genes of Soviet scientists with the American capital market under the changes of world history.
So how did Gapenchev make his fortune in fiber lasers throughout history and still earn the honor?
We have to go back to the crystal laser with the semiconductor laser as the light source for the bomb mentioned earlier.
Generally speaking, bulky crystals absorb high-energy photons with short wavelengths and convert them into low-energy photons with longer wavelengths. Part of the energy is always converted into thermal energy in a non-radiative transition.
If this part of the thermal energy cannot be dissipated in the massive crystal, it will be fatal and burn out in a short time, so the heat dissipation problem is very important.
If the bulk crystal can be made into a thin strip, the heat dissipation area will be very large, which can solve the problem. This is actually what an optical fiber looks like.
Someone made a glass laser in 1964. The crystal used fiber optics, although the light source was not a semiconductor laser.
However, the optical fiber itself was not developed at that time, and the defects were very large, and the light source was difficult to focus on the optical fiber, so there was no progress in this route for more than 20 years.
In the 1980s, semiconductor lasers like pumps made great progress, and optical fibers also made great progress with the development of network communications, and the technical conditions of fiber lasers gradually matured.
In 1987, the University of Southampton in the United Kingdom and Bell Laboratories in the United States proved the viability of an erbium-doped fiber amplifier and achieved an important scientific breakthrough.
But industrial advancement was achieved after many years of insistence on the IPG founded by Gapenchev in 1990.
Fiber lasers are high technology and involve multiple disciplines.
The power of the pumped semiconductor laser must be increased and the amplification performance of the fiber must be continuously improved.
The trick to improving fiber optics is to add various rare earth elements to it.
IPG is a typical high-tech enterprise in Western countries, and its research and development is not simple, and its product profit rate reaches 50-60%.
Fiber lasers have a number of the advantages of semiconductor lasers and the high beam quality advantages of crystal lasers.
From an industrial point of view, the advantages of fiber lasers are clear at a glance compared to CO 2 lasers and YAG lasers, and the advantages are so great that there is nothing comparable.
Fiber lasers have absolutely ideal beam quality as well as ultra-high conversion efficiency of semiconductor lasers, and are completely maintenance-free like optical fibers and LED lights, with high stability and small size. It really is a perfect product.
Of course, new high-tech products have a downside: they are expensive.
In this world, as long as any product finds a market in China, it will definitely sell well.
No matter how expensive the product is, as long as it can be industrialized in China, the cost can always be kept low.
At this point, we should mention another Chinese person who controls the fiber laser industry: he is Gao Yunfeng.
In 1996, Gao Yunfeng founded Han's Laser.
To enter the market, the fiber lasers produced by IPG must be integrated into various laser processing equipment, such as various “laser marking machines” and “laser cutting machines”.
Han's Laser found a cooperation model with IPG and purchased fiber lasers to manufacture processing machines.
Although IPG lasers are expensive, after the system is integrated, the whole machine will dilute the cost and perform well.
Therefore, the application of fiber lasers has prospered in China and the entire industrial chain is developing continuously.
In 2018, IPG and Han's Laser were elected as the governing units of the Laser Society of America.
The Laser Society of America (LIA) broadcast on the digital screen of the world-famous Thomson Reuters Building in Times Square, United States: “On the occasion of its 50th anniversary, the LIA would like to thank Coherent, Han's Laser, IPG Photonics and TRUMPF for their support . .”
Even now, the main market for IPG is still in China.
In 2018, 49% of IPG's sales depended on the Chinese market.
In 2017, IPG's market value reached more than 6 billion US dollars, while Han's Laser's market value reached 55 billion yuan.
The two are simply a pair of brothers.
It is clear that the current Sino-American trade war has affected high-tech stocks.
This question belongs to the general environment and is beyond the scope of this article.
More than 20 years ago, in the context of the disintegration of the Soviet Union, economic globalization and the take-off of Chinese industry, the fiber laser industry created the IPG and Han's Laser.
So now, 20 years later, where is the fiber laser industry?
In China, if it is said that the most disgusting IPG is Wuhan Raycus.
Min Dapeng, a doctor who remained in the US, Raycus launched its first set of 10W pulsed fiber lasers from 2008 to 20kW fiber lasers in 2018.
From IPG's perspective, Raycus has madly destroyed the market.
They cut prices and then reduced prices, operating with a small profit margin, which hurt market prices.
Every year, Ruike's price drops by almost 50% or more, which is incredible.
In 2010, IPG can sell a 20-watt fiber laser for more than 150 thousand. Now Raycus' bid is 8,800 and IPG can't compete.
Finally, even IPG's good brother Han's Laser started using it.
They say the trick is very simple. Have a domestic manufacturer order some fiber lasers to use, let them open up the interface definition, find some people to copy the success, and then stop buying.
Therefore, in IPG's opinion, the Chinese have effectively destroyed the market.
Of course, if the buttocks are in different positions, they will say different things.
At that time, the development of cutting-edge laser technology accounted for a third of the world in China.
From China's point of view, Chinese companies can, in fact, drastically reduce costs under the premise of ensuring a certain profit, without killing the market. The real effect is to promote the app quickly.
In fact, the popularity of industrial lasers depends on China's strong cost reduction and application promotion.
Countries such as India and Vietnam, with a certain scale of demand for manufacturing applications, also use low-cost industrial laser equipment made in China and are well recognized for Raycus products.
The Samsung factory in Vietnam uses many machines from the Chinese company.
Furthermore, the reason why Chinese companies can reduce costs like crazy is that the large-scale industrial chain is complete.
For example, optical lenses cost 10,000 in Germany and 1,000 in China.
Parts such as cylinder guides are produced in-house and there are few major parts without localization.
As localization advanced, the cost dropped quickly. In 2015, a 3-watt ultraviolet laser sold for 90 thousand, and now for 20 thousand.
Furthermore, China's large number of R&D personnel has turned industry competition into a competition to quickly satisfy customer needs.
When Han's Laser competed with South Korean EO in Vietnam, products with the same configuration were more than 100,000 cheaper, because IPG parts were cheap, and a large number of young engineers were sent to Samsung's factory in Vietnam for day and night debugging.
There are few Korean engineers sent by EO, and their hair is gray.
The American company's automatic laser equipment takes half a year, and the Chinese company directly quotes 30%, and the construction period is one month.
And in the United States, old engineers who are about to retire do this. No one will do that after they retire.
Throughout the history of laser development, the semiconductor laser technology passed down from the former Soviet Union has developed into a fiber laser due to China's huge demand and promotion of cost reduction.
Currently, Raycus is not the only fiber laser manufacturer in China, but the market seems to have formed a sea of red.
No one knows what this market will become in the future.
When analyzing something, sometimes we need to break out of existing silos. For example, due to the development of semiconductor laser coupling technology in recent years, high-power semiconductor lasers have gradually entered large-scale industrial processing applications.
See too:
A History of the Laser: 1960 – 2019
