If the terahertz frequency band can be used, the information age will go to a new level
In 1865, when British scientist Maxwell theoretically predicted the existence of electromagnetic waves, he probably did not expect that he opened up a new era for mankind - the information age.
In 1888, Hertz saw electromagnetic waves for the first time in an experiment. In 1905, Marconi used electromagnetic waves to realize transoceanic telegraphy. Since then, mankind has been advancing rapidly on the road of using electromagnetic waves.
From radios to televisions to wireless communications, from cell phones, microwave ovens to the Internet to radar, electromagnetic waves are changing our lives all the time.
In the past 150 years, human beings have continuously pursued the goal of faster, farther, and larger capacity information transmission. This goal has never ended and will not end. Human efforts to develop and utilize electromagnetic waves will continue.
Electromagnetic waves are generated by the coupling of periodic changes of electric and magnetic fields, and the speed of its changes is called frequency (unit Hertz, Hz).
According to the level of frequency, they can be arranged on an axis, similar to a family tree, which scientists call the electromagnetic spectrum.
All electromagnetic waves used in life can be placed on it. In fact, visible light seen by the naked eye is also a type of electromagnetic wave, and its frequency is 10¹⁵Hz, which is an electromagnetic wave that changes 10¹⁵ times per second.
Human beings have a very full understanding and utilization of electromagnetic waves, but only one band in the middle of the electromagnetic spectrum has not been fully developed, that is, the terahertz (THz) band. It is known as an unexplored virgin land in the electromagnetic spectrum, in the transition region from electronics to photonics.
The terahertz band generally refers to electromagnetic waves with a frequency of 0.1THz~10THz, and 1THz is equal to 10¹²Hertz.
Terahertz waves have the following characteristics: high carrier frequency, large bandwidth, and large communication capacity; good penetration and high resolution of radar imaging; low photon energy, good safety, and non-destructive detection; called the fingerprint spectrum.
This makes terahertz show important application value in many fields, and it has become the commanding heights of science and technology that countries are competing to seize.
In the United States, terahertz technology has been recognized as one of the top ten technologies that will change the future world; in the European Union, a number of transnational terahertz research programs have been launched; Japan has listed terahertz science and technology as the top of its scientific and technological strategic plan for the next ten years.
In fact, terahertz technology is not far away from people. In 2019, scientists observed a black hole for the first time, which is also known as a "doughnut", which is an observation using a terahertz astronomical telescope.
Terahertz technology will also play an important role in future battlefield reconnaissance, stealth and anti-stealth, precision guidance, electromagnetic countermeasures and other military fields.
Because the success or failure of the future information war depends on the control of information, and the fundamental of control of information is to control the electromagnetic spectrum. Terahertz is a spectrum resource that has not yet been applied. Whoever masters the terahertz spectrum resource first will occupy the future. Military commanding heights.
Terahertz is also an inevitable choice for future terrestrial wireless communications.
Taking mobile communication as an example, from the second-generation 2G era to the current 5G era, the communication rate has developed from 200kb to more than 100Mb, which has made each of us feel the convenience of communication.
In the future, in the era of terahertz mobile communication, the communication rate will exceed 100Gb, which is 3 orders of magnitude higher. We can imagine what changes terahertz mobile communication technology will bring to our lives?
On the one hand, with the development of terahertz technology, the architecture of electronic devices will undergo revolutionary changes, and the interaction of information will not depend on circuit boards and cables. cell phone signal jammer
On the other hand, with the rapid development of human society, the demand for large-capacity and high-speed information interaction is becoming more and more strong, and the space-based satellite Internet is booming.
Terahertz has shown great potential in information fields such as high-speed communication, electromagnetic countermeasures and remote sensing, as well as in frontier basic fields such as physics, chemistry, biology, and medicine.
In the field of terahertz biology, for example, infrared spectroscopy can only detect the vibrations of molecular bonds. Terahertz can measure these macromolecular organic groups composed of carbon, hydrogen, oxygen, and nitrogen elements, such as the group vibration and rotation spectra of protein macromolecules, so as to detect the molecular group configuration of organic matter in the form of fingerprint spectroscopy, etc. information.
In 2014, British scientists first observed the in vivo folding of proteins and proved that proteins can survive for a long time in vitro, opening the door to study the interaction between terahertz and biological systems.
The official launch of terahertz research in my country began at the 270th Xiangshan Science Conference. The author's team was commissioned by the state to organize experts and scholars to gather at the Fragrant Hill Hotel in Beijing to discuss the development direction of my country's terahertz science and technology.
Finally, everyone agreed that terahertz is both a "frontier of science and technology" and a "major national demand". And, over time, humans will make more full use of this spectrum.
How to break through the bottleneck of terahertz radiation and detection technology is the core problem that needs to be solved urgently in the development of terahertz field. It is foreseeable that breakthroughs in terahertz radiation and detection technology will bring major changes to human life and social development.
The development of terahertz has also gone through several stages since 2000: understanding terahertz, development of terahertz components, development of terahertz demonstration system and terahertz industrialization.
At present, terahertz is in a critical period of development from demonstration systems to industrialization. To promote the industrialization of terahertz technology in the four directions of wireless communication, medical equipment, biomedical systems, and safety detection systems, it is necessary to establish a complete innovation chain from terahertz basic research, terahertz components to terahertz system research as soon as possible At the same time, it will drive the high-quality development of related industries.
In September this year, the 46th International Infrared Millimeter Wave-THz Conference ended at the University of Electronic Science and Technology of China. This conference is the oldest and largest academic conference in this field, and it is the third time to be held in China, which fully shows that the "Chinese height" of terahertz research has received extensive attention from the world.
A new round of scientific and technological revolution and industrial transformation is advancing by leaps and bounds. As a scientific and technological worker, we must "have a big heart for the country", strengthen original and leading scientific and technological research, contribute wisdom and strength to the country's high-level scientific and technological self-reliance, and strive to build China into a global highland for terahertz research.
