What type of laser medium does ND:YAG represent?

ND:YAG, which stands for Neodymium-doped Yttrium Aluminum Garnet, is categorized as a solid-state laser medium. This classification arises because the laser operates using a solid crystal or a solid matrix that hosts the doping ions (in this case, neodymium). The properties of solid-state lasers typically include durability and the ability to produce high-energy pulses, which can be advantageous in various applications such as medical procedures, materials processing, and industrial uses.

Solid-state lasers like ND:YAG are differentiated from other types of laser mediums. For instance, gaseous lasers utilize a gas as their active medium, which typically has different operating characteristics and applications compared to solid-state lasers. Liquid lasers, meanwhile, contain a liquid medium that holds the dye or active species, while semiconductor lasers rely on the electronic properties of semiconductor materials. Each of these mediums influences the laser's performance, efficiency, and suitability for different tasks, further reinforcing the classification of ND:YAG as a solid-state laser.