Abstract
In recent years, the development of diode-pumped 100-J class laser has strongly advanced in Europe,
United States and Japan. In Europe, a 100 J × 10 Hz laser has been installed at an X-ray free electron laser
facility for academic use. The application of a 100-J class laser has also started in Japan in an industrial
field as a material processing platform to construct a laser-processing database, which is used in the
construction of a cyber-physical system for laser processing. We developed a diode-pumped cryogenically
cooled Yb:YAG ceramics laser as a material-processing platform. Our laser has demonstrated over
100-J output energy with a compact and simple system. This paper reviews the world’s trends of 100-J
class diode-pumped lasers and describes the development of a cryogenic-helium gas cooled Yb:YAG ceramics
laser amplifier. Finally, the current progress on the development of a 250-J class laser amplifier
toward 1-kJ laser technologies is presented.
