Laser-induced damage resistance of AlF3 films

AlF3 thin films were prepared by thermal evaporation at different substrate temperatures and deposition rates. The relationships between optical properties, mechanical properties and laser-induced damage threshold (LIDT) at 355nm of AlF3 films were discussed. Both absorption and stress increased with increasing substrate temperatures and deposition rates, which was a disadvantage to laser-induced damage resistance. Meanwhile, interfacial adhesion and hardness increased with substrate temperatures and deposition rates, which was an advantage to enhance the LIDT. The LIDT increased from room temperature to 200°C duo to increasing interfacial adhesion and hardness, and then decreased to 300°C duo to increasing absorption and stress. The LIDT decreased with deposition rates due to increasing absorption and stress.