One type of solid-state laser is an Nd:YAG laser. These discharge at 1064nm, close to infrared. The main source is the crystal yttrium aluminum garnet. Neodymium-doping replaces roughly 0.5% - 3% of the yttrium atoms. Bell Laboratories produced this type of laser in 1964. YAG lasers, along with CO2 and fiber, are popular for processing industrial applications and materials.
Diode-pumped lasers are excited through diode lasers with an 808nm wavelength. These lasers typically have an output power of 100 watts on average. The electrons of the neodymium atoms absorb the electric pump light to reach a greater energy level. Stimulated emission then releases the energy that is housed in the excited atoms.
One of the greatest technical challenges with a solid-state laser is the need for the structure to be composed of a single crystal throughout as well as high-purity and selective doping of the medium. It needs to have minimal heat loss with the greatest achievable efficiency. The solid-state laser can damage itself with excessive pumping power, meaning that it needs to be able to endure tremendous energy density.
Nd:YAG refers to a yttrium-aluminum-garnet crystal where the yttrium ions have been substituted by neodymium. The chemical symbol of yttrium = Y and the chemical symbol of neodymium = Nd, thus Nd:YAG. With these lasers, the neodymium-doping is roughly 0.5% - 3%. As the level of doping increases, the laser power also increases. However, the quality of the beam decreases as the power goes up. This is the same for all lasers.
Various types of lamps, including krypton arc, halogen, and xenon flash, or light or laser diodes may be used as pump sources. With power optically supplied and neodymium ions electrically stimulated, the Nd:YAG crystal is illuminated.