This large scientific device is about to start construction! What exactly is the attosecond, which is known as the fastest "flashlight" in human history?

According to news from Songshan Lake Science City in Dongguan, Guangdong, the advanced attosecond laser facility, a major national scientific and technological infrastructure, has officially obtained the budget approval of the National Development and Reform Commission and is about to start construction.

Image source: Dongguan Songshan Lake High-tech Industrial Development Zone Management Committee official website

The Advanced Attosecond Laser Facility is a major national scientific and technological infrastructure. On April 25, 2023, the Attosecond Science Center was officially unveiled in Songshan Lake, Dongguan. It is reported that after the completion of the Advanced Attosecond Laser Facility, it will become the first attosecond laser large scientific facility in Asia and the second in the world. The device is also expected to become the second major national scientific and technological infrastructure construction project ushered in by Songshan Lake Science City this year.

Attoseconds allow scientists to see "light"

What is an attosecond? Simply put, an attosecond is a unit of time, and 1 attosecond is equal to 10-18 seconds. For example, if it takes about 1 second for light to travel from the earth to the moon, in 1 attosecond, light can only transmit 0.3 nanometers, which is about one 200,000th of the diameter of a hair.

Human eyes may be able to see changes in the everyday world, but when scientists observe and study the microscopic world, such as the movement of particles in the microscopic world, or the capture of the movement of electrons in chemical reactions, it is impossible to achieve this with ordinary cameras or certain equipment, which requires a shorter exposure time. The concepts of "picosecond" and "femtosecond" gradually emerged. "Picosecond" (10 to the negative 12th power of seconds) can observe the dynamics of molecular rotation, and "femtosecond" (10 to the negative 15th power of seconds) can observe the vibration dynamics of chemical bonds. Using ultrafast optics to observe the dynamics of these ultrafast phenomena can deepen our understanding of matter and molecules.

In the continuous research, "attosecond" came into being and became a new tool for researchers to explore the world of electrons. Through attosecond lasers, scientists can observe the movement of electrons inside atoms and explore their interactions, just like watching a slow-motion movie, just like being able to "catch" light.

Attosecond laser: pressing the "super shutter" for electron movement

In the microscopic world, when electrons move between atoms, their positions and energies change at the order of attoseconds. If you want to explore the motion state of electrons and take videos of them, you can’t do without the help of attosecond laser pulses. Attosecond laser pulses are flashes of light that last at the order of attoseconds.

Attosecond lasers provide a new technical means for studying major basic scientific problems in physics, chemistry, materials, information, biomedicine and other disciplines . On October 3, 2023, the Royal Swedish Academy of Sciences announced that the Nobel Prize in Physics that year would be awarded to Pierre Agostini, Ferenc Kraus and Anne Lülliet in recognition of their "experimental methods for generating attosecond light pulses for studying electron dynamics in matter."

Image source: Nobel Prize official website

Attosecond pulsed light technology is the fastest time scale currently mastered by humans. It is like a ruler. The finer the scale of the ruler, the higher the measurable accuracy. The development of attosecond pulsed laser technology will lead to many major breakthroughs in scientific and technological research in the fields of free electron lasers, controllable high-temperature superconductors, and electronic information processing.

Comprehensive sources: Dongguan Songshan Lake High-tech Industrial Development Zone Management Committee official website, Science and Technology Daily, Xinhua Daily, etc.