>Alright... Now I get why there was that gas story about the "chinese cooling". When I read it the first time I stopped think "Wtf wait.. They certainly aren't the first ones to have figured that gas can cool it..." so I skipped it, thinking that well, if that's what they say... Yeah they use chemical lasers because they have the highest light energy output for their size/weight. There has been a lot of work on newer technologies like diode pumped solid state stacked gain medium systems that use a bunch of laser diodes to pump a gain medium at right angles to output a big beam. Stacking multiple DPSS gain medium module can increase the power in a rather compact setup, but they are definitely power hungry systems. The National Ignition Facility has such laser systems for use as the energy delivery system in a hot fusion reactor using deuterium pellets as the fusion fuel. They are impressive lasers, but chemical lasers still beat them on power input to light output ratios.