Nuclear fusion occurs when atomic nuclei forcefully collide and fuse under high-temperature and high-pressure conditions, releasing powerful energy. Extensive research into this phenomenon, which takes place in the sun, is being held with the goal of mimicking it on Earth and using it to generate power. A high-temperature state in which nuclear fusion could occur was maintained for 48 minutes at the National Institute for Fusion Science. Meanwhile, a private optical device manufacturer developed a device that irradiates deuterium capsules with a semiconductor laser.