Scientists have invented a technique for generating ultra-high intensity lasers. The researchers compared the intensity to the energy of all the sunlight received on Earth, focused on an area as small as a dust cloud.
Research leader Chang-hee Nam of the Gwangju Institute of Science and Technology in South Korea said they were able to achieve a laser intensity that is like focusing the world’s sunlight on such a small area of only 10 microns. Such an area is about the size of a grain of dust or a red blood cell. This laser pulse reaches an intensity of 1023 watts per square centimeter in a few femtosecond moments.
The team allowed the laser to pass through an obstacle path that caused the laser to be reflected, as well as controlling the motion of the photons that make up the laser to increase its intensity. While lasers have the characteristics of particles (because light is a substance made up of individual photons), they also have the characteristics of waves of energy, and the researchers found that controlling the laser’s wavefront (similar to the front end of a wave) is also important for focusing the laser’s energy.
Chang-Hee Nam said it took their research group a decade to achieve this technology. “It took us more than a decade to develop this femtosecond laser technology. in 2017 we reached an output power of 4 PW. Then we focused our goal on focusing the laser beam from the beginning of 28 cm to 1 micron. To reach this step, we used deformable mirrors to help control the wavefront surface of the laser.”
The study describes that the ultra-high power laser helps the laser beam to be distortion-free; the deformable mirror ensures that the beam is focused very precisely. The two aspects work together to achieve this high-intensity laser.
Exploring the interaction between light and light
Lasers of such high intensity help scientists explore the early universe. With the high-intensity laser we can study the phenomenon of positive and negative electron pairs generated by the interaction between light and light,” said Chang-Hee Nam. Theories speculate that such phenomena existed within the early universe, within supernova explosions or within plasma jets ejected from black holes.”
Previously scientists could only speculate through theoretical calculations; with such high-intensity lasers, scientists can begin to explore these theories by performing simulations in the laboratory.
May become a new treatment for cancer
High-intensity lasers hold the promise of becoming an effective treatment for cancer.
Proton therapy is a new generation treatment for cancer, using a gas pedal to irradiate a positively charged beam of protons into a patient’s cancer cells. This therapy has shown initial results, except that the accelerator requires a large radiation shield and is costly. This high-intensity laser can achieve similar results at a lower cost that more patients can afford, Nam Chang Hee said.
The laser is fleeting, but it looks like it will have a huge impact on the physics community and other scientific fields. The study was published May 6 in the journal Optical Design (Optica).