Theoretical analysis for temperature dependence of laser- induced damage threshold of optical thin films

8th International Conference on Inertial Fusion Sciences and Applications

Mikami, K.^1,2 ; Motokoshi, S.^3 ; Somekawa, T.^3 ; Jitsuno, T.^1 ; Fujita, M.^3 ; Tanaka, Ka^2 ; Azechi, H.^1

Institute of Laser Engineering, Osaka University, 2-6 Yamada-oka, Osaka Suita

565-0871, Japan^1

Graduate School of Engineering, Osaka University, 2-1 Yamada-oka, Osaka Suita

565-0871, Japan^2

Institute for Laser Technology, 1-8-4 Utsubo-honmachi, Nishi-ku, Osaka

550-0004, Japan^3

关键词: Calculation results;    Electron heating;    Electron multiplication;    Free electron;    Laser induced damage thresholds;    Optical thin films;    Scaling model;    Temperature dependence;   

Others  :  https://iopscience.iop.org/article/10.1088/1742-6596/688/1/012065/pdf
DOI  :  10.1088/1742-6596/688/1/012065

来源: IOP

【 摘 要 】

The temperature dependence of the laser-induced damage threshold on optical coatings was studied in detail for laser pulses from 123 K to 473 K at different temperatures. The laser-induced damage threshold increased with decreasing temperatures when we tested long pulses (200 ps and 4 ns). The temperature dependence, however, was reversed for pulses shorter than a few picoseconds (100 fs testing). We propose a scaling model with a flowchart that includes three separate processes: free-electron generation, electron multiplication, and electron heating. Furthermore, we calculated the temperature dependence of laser-induced damage thresholds at different temperatures. Our calculation results agreed well with the experimental results.