Erbium-dopedunder Yttrium Aluminum Garnet is widely used as an idea laser medium for 2940 nm wavelength. It works well room temperature with high slope efficiency and good optical quality.
Erbium YAG crystal | Er YAG crystal | Er YAG laser |
It has wide pump band from 600~800 nm. Due to the strong water and human body fluid absorption at this wavelength, 2940nm laser has various applications of dermatology. And 2940nm wavelength is the absorption peak of water, so this machine instantly heats the skin to over 300degree gasifying skin tissues without damaging the surround skin (normally caused by short pulse). In theory, 2940nm laser can gasify deeply into 30m, but thermal damage is only limited around 30-50m in surrounding tissues (by long pulse), therefore it exfoliates shallow skin tissues, which helps skin recover more quickly, leads to slight thermal damage and low rate of hyper-pigmentation. Due to its wavelength, 2940nm pixels laser absorbs water 16 times more than CO2 laser, thus no exfoliation plateaus as CO2 laser, which thanks to its instant absorption to water, so laser energy brings gasification, but not thermal effect (by short pulse). Clinically it mainly works for exfoliation, so it applies to all Fitzpatrick skin types.