Photonic chips, the name sounds lofty, with a hint of futuristic sci-fi.
In fact, the photonic chip and the electronic chip used now are twins born at the same time in the eighties of the last century.
If we want to talk about the cutting-edge theory of photonic chips, in fact, it has been proposed as early as 1887.
The later result of this theory was called photonic crystals.
When the time came to 1969, Bell Labs in the United States proposed the concept of integrated optics, which had the way to research in the field of chips.
Here's the problem.
Are photonic chips about the same as electronic chips?
Much worse! First of all, photonic chips are built on the basis of light, and light is used as a carrier for information transmission and data transportation.
In the whole world, is there anything faster than light?
According to Einstein's special theory of relativity, it is impossible for everything to exceed the speed of light.
Obviously, photonic chips are better than electronic chips.
So why have electronic chips been running for so long, and now there is news of photonic chips?
Theory belongs to theory, research belongs to research, and everything that can be popularized in practice is provided that the technology is mature and stable enough.
Electronic chips have a key technology, as early as the emergence of electronic chips, has tended to mature.
This is transistor technology, this component is equivalent to a hub, which can re-edit one, or even more than one electrical signal, into a signal for output.
Starting with transistors, analog signals, digital signals, and so on appeared.
This allowed electrical signals to be transformed into signals that humans needed and could be interpreted, and electronic chips flourished on this basis.
So what was the situation with photonic chips at that time?
In order to appear photonic chips, similar components are also needed to convert various lights, even electromagnetic waves of different wavelengths, into signals that can be stably controlled by humans.
And this component is called an optical transistor.
But unfortunately, there has been no breakthrough in the research of optical transistors.
For example, the biggest challenge is that the output signal is actually longer than the wavelength of the input signal, and the wavelength becomes longer, so to capture this signal, you have to increase the distance, otherwise how to capture?
Therefore, the volume of the photonic chip is often made to be huge.
Of course, there is another way, which is to make the optical transistor very small, down to the micron level.
What a joke in the eighties of the last century.
This difficulty has not been overcome, which has given electronic chips time for rapid development.
Nowadays, the development of electronic chips has actually reached a bottleneck, which is often referred to as Moore's Law.
What is Moore's Law?
This law is one of the founders of Intel. Moore brought it up.
This roughly means that the number of components that can be accommodated on an integrated circuit will double in one to two years, and of course, the performance will also double.
This law shows that the speed of information development is extremely amazing.
This development has been going on for half a century now.
Then there is a problem, a small integrated circuit area is so large, the number of components is constantly doubling, and finally the number of components installed on a small integrated circuit will become a terrifying number.
Integrated circuits will face the situation that they cannot fit components.
Therefore, for the process of chips, many scientists have begun to discuss whether electronic chips have come to an end and should change the runway.
Then the photonic chip, which has been left out in the cold for 50 years, is on the agenda.
Speaking of this, many people will ask: "What about the lithography machine?" ”
If photonic chips are launched and can be industrially mass-produced, the lithography machine should be put in a museum!
The development of photonic chips.
In other words, the performance of electronic chips depends on the number of integrated transistors.
In this case, not only will the bottleneck of Moore's Law be encountered, but as the number of transistors increases, the energy consumption will also increase, and even a series of problems such as crosstalk and delay will occur.
And these problems will become more and more difficult to overcome as the number of transistors increases.
Taking energy consumption as an example, about 40% of the energy consumption of a data center will be wasted on heat dissipation.
Nearly half of the energy is lost.
Data centers currently account for 1% of the world's energy consumption.
The figure of 1% may seem small, but it is quite a scary number to know that the energy consumed worldwide is quite terrifying.
For example, a company like Google consumes more energy in a year than Sri Lanka as a country.
If you don't believe it, you can refer to the mining machines that mined virtual currencies in the past, and the power consumed by a mining machine is a very terrifying data.
In 2009, the world's mining machines consumed more energy than Google alone consumed in a year.
And in this consumption process, a large amount of carbon dioxide gas will appear.
What about photonic chips?
Photonic chips do not have such trouble, this kind of chip uses light as the carrier of information, and has the characteristics of low power consumption, high bandwidth and high parallelism.
Because the photonic chip has no resistance, it is a photon generated by a laser, and then passes at a very fast speed, a waveguide, a modulator, a reflector.
This process cannot be said to be without the production of heat, but it is very rare.
Therefore, if you want to transmit data in large capacity, photonic chips are the best choice.
The next industrial revolution is based on artificial intelligence, and photonic chips are chips that can provide efficient services for artificial intelligence.
This is incomparable to electronic chips.
Therefore, various countries have high R&D investment in photonic chips.
After all, photonic chips will become a core component of artificial intelligence.
Other countries' investments in photonic chips
The first is the United States.
In fact, as early as 1990, Bell Labs in the United States had already designed a prototype of a photonic computer.
This prototype uses light to do the calculations.
Although the prototype came out, they couldn't do it, and the electronic components in it were reduced, so the components of the photonic computer at that time could not be compact, so that the volume was too large to be compared with the electronic chip computer.
Of course, it is not possible to carry out industrial mass production.
Without the impetus of economic interests, the project was stopped.
Nowadays, with the advancement of science and technology, especially the manufacturing of photonic devices, photonic components are also shrinking.
In March 2016, researchers from three universities in the United States developed a photonic chip.
At that time, it was announced that this photonic chip was the world's first full-fledged, and moreover, a processor that used light to transmit data.
The data transmission speed of this chip per square millimeter can be defeated by 300,000 megabits, which is ten to fifty times the speed of electronic chips at that time.
So how big is this photonic chip?
Eighteen square millimeters, but on top there are two processor cores, one transmitting and one receiving, and the overall component has 70 million transistors, as well as 850 photonic components.
The number of parts on the chip is definitely a terrifying number.
Of course, this photonic chip has not been able to be used in commercial use.
In 2021, a startup in Boston, Massachusetts, announced that they had developed a photonic chip that consumes only one-sixth of the power of chips of the same level.
At this point in time, various industries in the field of artificial intelligence in the United States have also begun to develop photonic chips accordingly.
And what about other countries?
On September 28, 2017, the University of Oxford in the United Kingdom announced that their school's researchers had also made breakthroughs in photonic chips.
It can even simulate the structure of human cranial nerves and carry out high-speed transmission of information.
Making a photonic chip that can be compared to the structure of human brain nerves is a remarkable breakthrough, you must know that the human brain is the most mysterious, and scientists from all walks of life have not solved all the secrets in it.
There is also the fact that the brain is a place that can process and store information at the same time, which is not easy for any chip to do, and the energy consumption of this working process is quite low.
After all, if the energy consumption of the brain is high, the temperature will rise, and the intracranial pressure will become high, and the human brain will have problems.
Therefore, the development of photonic chips can be compared with the structure of the human brain, which is definitely a very remarkable research achievement.
Researchers at the University of Oxford published their findings in the American journal Science Advances.
In this report, it is also mentioned that the reason why they can have a structure similar to the human brain is that they used very special phase change materials, and then combined with the optical path, to develop a photonic chip.
And it runs a thousand times faster than the human cranial nerves.
Of course, these achievements have been kept in the scientific laboratory, and there is still a certain gap from industrial mass production.
On July 11, 2022, Australian scientists also made a breakthrough in photonic chips.
The first self-calibrating photonic chip was developed, which is equivalent to a highway bridge built on a highway with a photonic chip.
It can be used to connect various photonic chips.
So how is China on the road to photonic chips?
On April 11, 2024, Tsinghua University successfully developed the Taiji Photonic chip, which is said to have a computing speed of 1,000 times.
Of course, as is customary, the results of this research were written and published in the journal Science.
The 1,000-fold increase in computing speed is definitely a breakthrough and also means that China is at the forefront of the world in photonic chips.
In fact, in China, the project on photonic artificial intelligence chips has already been launched, in 2019, in Shunyi.
This technological breakthrough will promote the mass production of photonic chips faster.
Once mass production begins, it will be possible to get rid of the current high-process lithography machine and achieve lane change and overtaking.