Neodymium-doped yttrium aluminum garnet (Nd:YAG) laser is one of the most common solid state lasers that emits light with a wavelength of 1064 nm (near-infrared region). However, second, third, fourth, and fifth harmonics of Nd:YAG laser can produce light with a wavelength of 532, 355, 266, 213 nm, respectively. Nd:YAG lasers can operate in the both continuous and pulse mode. Among different laser machines, different harmonics of Nd:YAG laser have been used frequently by scholars. laser irradiation of materials by Nd:YAG laser is one of the simplest and promising manners in several fields such as cutting, drilling, welding, etching, and engraving diverse materials even metals. At the same time, industrial applications of Nd:YAG lasers include synthesis of nanocomposites and Carbon Quantum Dots, generating micro- and nano-size emulsions. In the last two decades, Nd:YAG and fiber lasers have been utilized to produce nanoparticles and nanocomposites. On top of that, production of new layered structures on the irradiated area, hydrogen production through laser irradiation of organic liquids, variation of band gap and phase, surface modification, and creation of hydrophobic surfaces are the other studied applications of Nd:YAG laser. In this chapter, applications of Nd:YAG lasers have been studied.
