Abstract:
Optical coatings are the uttermost weak link in the laser system and may easily be damaged. The temperature of films rises quickly under the irradiation by a pulsed laser of high repetition rate, that leads to a sharp variation of the stresses in the coatings and their configurations, and is followed by macroscopic and catastrophic damages. In this paper, we measured the maximal temperature variation in films irradiated by DPL laser with repetition rate of 10 kHz in real time using infrared thermography camera and analyzed the factors that can affect the temperature variation in coatings. The results indicate that the temperature rise of coatings decreases with the increase of thermal conductivity of the substrate, and with the increase of thickness. The relationship between the maximal temperature rise of films and absorbing power density is almost linear.