High power laser technology

High power laser is divided into two kinds according to the output characteristics. One is high peak power laser, and another is high average output laser. The laser used at present for nuclear fusion has the output energy from several kJ to 100 kJ at very short pulse width from 100 ps to 10 ns, and the peak power (output energy/pulse width) has reached 50 x 1012 W. In the next high gain experiment, in which the energy gain by nuclear fusion reaction (nuclear fusion reaction energy/infused laser energy) becomes about 100 times, the system of 10 ns and 10 MJ is studied. Thereafter, as the laser for a nuclear fusion reactor which carries out actual power generation, it is considered that the laser generating the output energy of several MJ at 1-10 Hz and of the average output of 10 MW class is necessary. So it is an important subject to obtain not only high peak power but also high average output. In this report, the present status of the laser for inertial confinement fusion experiment, its elementary technology and the direction of development hereafter are reported. In addition, the laser driver for reactor, the polishing and coating of optical components and so on are described. (K.I.)