First-principles simulation of the optical response of bulk and thin-film -quartz irradiated with an ultrashort intense laser pulse

高強度超短パルスレーザーを照射された水晶の固体及び薄膜の光学応答の第一原理計算

Lee, K.-M.*; Kim, C. M.*; 佐藤 駿丞*; 乙部 智仁; 篠原 康*; 矢花 一浩; Jeong, T. M.*

Lee, K.-M.*; Kim, C. M.*; Sato, Shunsuke*; Otobe, Tomohito; Shinohara, Yasushi*; Yabana, Kazuhiro; Jeong, T. M.*

超短パルスレーザーを照射した光学措置の応答とアブレーション閾値を第一原理多階層シミュレーションを用いて調べた。固体及び薄膜状水晶の反射率変化及びアブレーション閾値をしらべ、それらが実験値をよく再現することを確認した。この成果から我々の手法が光学素子のレーザー加工閾値の見積に使用できることがわかった。

A computational method based on a first-principles multiscale simulation has been used for calculating the optical response and the ablation threshold of an optical material irradiated with an ultrashort intense laser pulse. The method was applied to investigate the changes in the optical reflectance of quartz bulk, half-wavelength thin-film and quarter-wavelength thin-film and to estimate their ablation thresholds. Despite the adiabatic local density approximation used in calculating the exchange-correlation potential, the reflectance and the ablation threshold obtained from our method agree well with the previous theoretical and experimental results. The method can be applied to estimate the ablation thresholds for optical materials in general.