Ti:Sapphire (Ti:Al2O3) is one of the first tunable laser materials formulated. At a continuous lasing range of 700-1000nm it certainly is the most used materials for scientific and laboratory settings, taking the place of several lasers and messy dyes. The very first material to make a laser is RUBY (Cr:Al2O3) for 694nm. Ruby is being used for Tattoo removal and other restorative skin procedures.
Fluoride materials available include Nd:YLF, Cr:LiSAF and Cr:LiCaGaF. Yttrium Lithium Fluoride exhibits a polarized beam for added line definition and greater efficiency. YLF is doped with either Erbium (Er:YLF) or Neodymium (Nd:YLF) to lase at 1342 and 1047nm. Cr:LiSAF & Cr:LiCaGaF are newer materials for lasing in the 700-900nm area. These materials have proven invaluable in scientific, defense and medical applications.