The effect of thermal annealing on the optical properties, microstructure, and laser-induced damage threshold(LIDT) of HfO2/Ta2O5/SiO2 HR films has been investigated. The transmission spectra shift to a short waveleng...The effect of thermal annealing on the optical properties, microstructure, and laser-induced damage threshold(LIDT) of HfO2/Ta2O5/SiO2 HR films has been investigated. The transmission spectra shift to a short wavelength and the X-ray diffraction peaks of monoclinic structure HfO2 are enhanced after thermal annealing. The calculated results of the m(-111) diffraction peak show that the HfO2 grain size is increased, which is conducive to increasing the thermal conductivity. Thermal annealing also reduces the laser absorption of high-reflection films. The improvement of thermal conductivity and the decrease of laser absorption both contribute to the improvement of LIDT. The experimental results show that the highest LIDT of 22.4 J/cm2 is obtained at300°C annealing temperature. With the further increase of annealing temperature, the damage changes from thermal stress damage to thermal explosion damage, resulting in the decrease of LIDT.展开更多
基金supported by the Jilin Science and Technology Development Plan(Nos.20180519018JH and20190302052GX)the Jilin Education Department“135” Science and Technology(No.JJKH20190543KJ)+1 种基金the National Natural Science Foundation of China(No.11474038)the Excellent Youth Foundation of Jilin Province(No.20180520194JH)
文摘The effect of thermal annealing on the optical properties, microstructure, and laser-induced damage threshold(LIDT) of HfO2/Ta2O5/SiO2 HR films has been investigated. The transmission spectra shift to a short wavelength and the X-ray diffraction peaks of monoclinic structure HfO2 are enhanced after thermal annealing. The calculated results of the m(-111) diffraction peak show that the HfO2 grain size is increased, which is conducive to increasing the thermal conductivity. Thermal annealing also reduces the laser absorption of high-reflection films. The improvement of thermal conductivity and the decrease of laser absorption both contribute to the improvement of LIDT. The experimental results show that the highest LIDT of 22.4 J/cm2 is obtained at300°C annealing temperature. With the further increase of annealing temperature, the damage changes from thermal stress damage to thermal explosion damage, resulting in the decrease of LIDT.
