If the terahertz frequency band can be used, the information age will rise to a higher level
In 1865, when the British scientist Maxwell predicted the existence of electromagnetic waves theoretically, he might not have thought that he opened up a whole new era for mankind-the information age.
In 1888, Hertz first saw electromagnetic waves in an experiment. In 1905 Marconi used electromagnetic waves to realize transoceanic telegraphs. Since then, human beings have been advancing rapidly on the broad road using electromagnetic waves.
From radio to TV to wireless communication, from mobile phones and microwave ovens to the Internet to radar, electromagnetic waves change our lives all the time.
In the past 150 years, human beings have continuously pursued the goal of faster, farther, and larger capacity of information transmission. This goal has never ended and will not end. Mankind's efforts to develop and utilize electromagnetic waves will continue.
Electromagnetic waves are generated by the coupling of the periodic changes of electric and magnetic fields, and the speed of their changes is called frequency (unit hertz, Hz).
According to the frequency, it 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, the visible light seen by the naked eye is also a kind of electromagnetic wave, with a frequency of 10¹⁵Hz, that is, an electromagnetic wave that changes 10¹⁵ times per second.
Humans have already fully understood and used 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 a virgin land in the electromagnetic spectrum that has not yet been exploited and is in the transitional region from electronics to photonics.
Terahertz band generally refers to electromagnetic waves with a frequency of 0.1THz~10THz, and 1THz is equal to 10¹² Hz.
Terahertz waves have the following characteristics: high carrier frequency, large bandwidth, large communication capacity; good penetration, high radar imaging resolution; low photon energy, good safety, and non-destructive detection; covering the characteristic spectrum of most materials, and is It is called fingerprint.
This allows terahertz to show important application value in many fields and become the commanding heights of science and technology that countries are vying to seize.
In the United States, terahertz technology has been recognized as one of the top ten technologies that will change the world in the future; in the European Union, a number of transnational terahertz research programs have been launched; and Japan has listed terahertz science and technology as the top technology strategic plan for the next ten years.
In fact, terahertz technology is not far away from people. In 2019, scientists observed black holes for the first time, which is also known as "doughnuts", which are observations made with terahertz telescopes.
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 future informatization warfare depends on the control of information rights, and the basis for the control of information rights lies in the control of electromagnetic spectrum rights. Terahertz is an unused spectrum resource. Whoever masters terahertz spectrum resources first will occupy the future. Military commanding heights.
Terahertz is also an inevitable choice for future terrestrial wireless communications.
Take mobile communication as an example. From the second-generation 2G era to the current 5G era, the communication rate has grown from 200kb to more than 100Mb, which has made each of us feel the speed and convenience of communication.
In the future development to the era of terahertz mobile communications, the communication rate will exceed 100Gb, which is three orders of magnitude higher. We can imagine how much terahertz mobile communications 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 rely on circuit boards and cables.
On the other hand, with the rapid development of human society, the interactive demand for large-capacity and high-speed information is becoming stronger and stronger, and space-based satellite Internet is booming.
Terahertz has shown great potential in information fields such as high-speed communications, electromagnetic countermeasures and remote sensing, as well as cutting-edge basic fields such as physics, chemistry, biology, and medicine.
Taking the terahertz biological cross field as an example, infrared spectroscopy can only detect the vibration of molecular bonds. Terahertz can measure these macromolecular organic groups composed of carbon, hydrogen, oxygen, and nitrogen, such as the group vibration and rotation spectra of protein macromolecules, so as to detect the molecular group configuration of organic substances in the form of fingerprint spectra. information.
In 2014, British scientists first observed the living folding of proteins and proved that proteins can survive for a long time in vitro, opening the door to studying 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 entrusted 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." Moreover, as time goes by, humans will make fuller 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 gone through several stages since 2000: understanding of terahertz, development of terahertz components, development of terahertz demonstration systems, and industrialization of terahertz.
At present, terahertz is in a critical period of development from the demonstration system to the industrialization. To promote the industrialization of terahertz technology in the four directions of wireless communication, medical equipment, biomedical systems, and safety detection systems, a complete innovation chain from terahertz basic research, terahertz components to terahertz system research must be established as soon as possible At the same time, it will promote 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 top academic conference with the longest history and the largest scale in this field. It is the third time that it has been held in China. It also fully demonstrates that the "Chinese height" of terahertz research has received widespread attention from the world.
