I had a buddy who built a CO2 UV laser from a Scientific American
Amateur Scientist column. It packed quite a punch for all of five to
ten nanoseconds (capacitor arc discharge from a cap of several hundred
picofarads charged to twenty thousand volts using a very low
inductance lead design). He chose to be careful by aiming it out the
window into the sky.

by carfull you mean he made sure no planes or satalites birdies etc
were in his 'aimed' path??




He fired the laser and cracked the window. The
thermal expansion of the glass was sufficiently slow enough to
accumulate enough stress (due to the attenuation) to create a
fracture. Classic thermal runaway.