A broadband (~176 nm, R>98%, 'lambda'0=800 nm) and high laser-induced damage threshold (LIDT=2.4J/cm2) TiO2/HfO2/SiO2 high reflector (HR) for Ti:sapphire chirped-pulse amplification (CPA) laser system is fabricated by the electron beam evaporation. The refractive index and extinction coefficient of TiO2 and HfO2 films are calculated from single-layer films' transmittance spectra. The properties of HR are mainly determined by the high refractive index material. The high refractive index leads to wide bandwidth. A low extinction coefficient indicates low absorption and high LIDT. The possible damage mechanism of HR is discussed.
© 2007 Chinese Optics Letters
Jianke Yao, Weiqiang Zeng, Zhengxiu Fan, Hongbo He, and Jianda Shao, "Laser-induced damage of high reflectors for Ti:sapphire laser system," Chin. Opt. Lett. 5, 724-726 (2007)