Ho,Cr,Tm:YAG -yttrium aluminium garnet laser crystals doped with chromium,thulium and holmium ions to provide lasing at 2.13 microns are finding more and more applications,especially in the medical industry.The inherent advantage of the crystal crystal is that it employs YAG as the host. YAG’s physical,thermal and optical properties are well known and understood by every laser designer. It has wide applications in surgery, dentistry, atmospheric testing, etc.