Question: which laser types is used in?
Answer: Helium Neon Laser: The first CW system was the helium neon (HeNe) gas mixture. ... 
Argon, Krypton, and Xenon Ion Lasers. ... 
Carbon Dioxide Laser. ... 
ND:YAG Laser Systems: ... 
Excimer Lasers: ... 
Semiconductor Diode Lasers. ... 
Other Lasers: