IF/P7-8 “GENBU”-Laser Development with Cryogenic Yb:YAG Ceramic for Fusion Energy Reactor Driver

A new diode-pumped laser fusion driver has been conceptually designed. The output power is 1.2 MJ and 0.1 MJ for a compression laser and a heating laser, respectively, at 16 Hz repetition rate and 17% electrical-optical efficiency. We have proposed two new technologies into the laser system to improve its laser output characteristics dramatically. One is cryogenic Yb:YAG ceramics as a laser material and the other is a large-aperture active-mirror as an amplifier architecture. An 1 kJ near-infrared laser is a basic unit for both compression and heating lasers, and its demonstration will become a milestone of the new driver. Recently, “GENBU”-laser has been designed in details for not only a milestone of the new reactor driver but also a tool for advanced application fields. A joule-class laser system of “GENBU-Kid” is under construction for power-scaling up to 1 kJ.