Nd: YAG crystal rod is used in Laser marking machine and other laser equipment.  It is the only solid substances that can work continuously at room temperature, and is the most excellent performance laser crystal. Also, the YAG (yttrium aluminium garnet) laser can be doped with chromium and neodymium in order to enhance the absorption characteristics of the laser.The Nd,Cr:YAG laser is a solid state laser.Chromium ion(Cr3+) has a broad absorption band; it absorbs the energy and transfers it to the neodymium ions(Nd3+) by way of dipole-dipole interactions.Wavelength of 1064nm is emitted by this laser. The laser action of Nd:YAG laser was first demonstrated at the Bell Laboratories in the year of 1964.The Nd,Cr:YAG laser is pumped by a solar radiation.By doping with chromium,the energy absorption capacity of the laser is enhanced and ultra short pulses are emitted.