YAG laser is a type of laser. YAG is the abbreviation of yttrium aluminum garnet crystal (Y3Al5O12), which is a laser matrix with excellent comprehensive properties (optical, mechanical and thermal).
Among them, Nd:YAG laser (neodymium-doped yttrium aluminum garnet laser) is by far the most widely used solid-state laser. Because the concentration of neodymium that can be doped is very high, up to 1.3×1020/cm3 or more, the unit volume of the working substance can provide a relatively high laser power.
The Nd:YAG laser, like the Nd glass laser, uses Nd3+ as the active ion, but the Nd3+ energy level width in Nd glass is larger. The emission wavelength of the Nd:YAG laser is 1.064 microns, and the laser linewidth is less than 1 nanometer. A YAG laser generally consists of a laser rod, a pump lamp, a concentrator and a resonator. The picture shows a schematic diagram of a YAG laser in continuous operation. An elliptical concentrator coated with a gold or silver reflector concentrates the pump light on the YAG rod. Usually a krypton flash lamp is used as the pump light source. If Cr3+ ions are doped in addition to Nd3+ ions, xenon lamp pumping can be used, and the excited Cr3+ ions will convert energy to Nd3+ ions at this time. YAG lasers can also be pumped with semiconductor lasers. YAG lasers are characterized by low threshold, long crystal life, and very high fluorescence quantum efficiency, which is close to 1 in the absorption spectrum range of 0.7 to 0.8 nanometers. The thermal conductivity of YAG material is far better than that of neodymium glass, so it can be made into a pulsed laser with a high repetition rate, and can even achieve continuous operation at room temperature. In addition, YAG lasers have good beam quality, so Nd:YAG lasers are the most widely used of all solid-state lasers, and can be used in material processing, holographic technology, ranging, target lighting and indication, surgery and other fields. Like other crystal lasers, the disadvantage of YAG lasers is that it is difficult to grow large-sized crystal rods.
In addition to doping Nd ions, also try to dope Er, Ho, Tm, Cr plasma or a combination of these components, so as to obtain other wavelengths of laser oscillation.