Ruby was the first solid-state laser material-- demonstrated by Ted Maiman in 1960. With two broad absorption bands it is conveniently pumped with flash lamps producing pulsed deep red laser light at 694.3nm. Ruby is one of the most robust solid-state laser materials with a thermal shock resistance three times that of Nd:YAG.
Ruby’s wavelength makes it ideal for medical applications such as hair and tattoo removal.