There are many factors that influencing the laser induced damage threshold (LIDT) and one of them is damage induced due to standing wave electric fields generated inside the multilayer coating on the irradiation of the laser. HfO2 and SiO2 are preferred materials for high damage threshold coatings stack. (HL)^n, where “H” is quarter wave optical thickness (QWOT) for high index materials and “L” is quarter wave optical thickness (QWOT) of low index materials for high reflectance mirror to achieve high reflectivity at reference wavelength. One of the problems with such a stack is that the peak standing wave electric field falls on the interface of low and high index materials which reduces the laser damage threshold of the high reflectance mirror. In the present study, we have optimized the minimum number of layers in quarter wave stacks to go non quarter so that this standing wave electric field shifts away from the interface to the high damage threshold region.
Kumar, Sunil; Shankar, Ajay; and Kishore, Nawal
"Tuning of Laser Damage Threshold by Adjusting Field Zones in Multilayer Dielectric Coatings,"
International Journal of Thin Film Science and Technology: Vol. 10
, Article 5.
Available at: https://digitalcommons.aaru.edu.jo/ijtfst/vol10/iss1/5