title: Ultrafast pre-breakdown dynamics in Al₂O₃SiO₂ reflector by femtosecond UV laser spectroscopy.
abstract: Ultrafast carrier dynamics in Al2O3/SiO2 high reflectors has been investigated by UV femtosecond laser. It is identified by laser spectroscopy that, the carrier dynamics contributed from the front few layers of Al2O3 play a dominating role in the initial laser-induced damage of the UV reflector. Time-resolved reflection decrease after the UV excitation is observed, and conduction electrons is found to relaxed to a mid-gap defect state locating about one photon below the conduction band . To interpret the laser induced carrier dynamics further, a theoretical model including electrons relaxation to a mid-gap state is built, and agrees very well with the experimental results.. To the best of our knowledge, this is the first study on the pre-damage dynamics in UV high reflector induced by femtosecond UV laser.
authors.forename: Juan
authors.initials: J
authors.lastname: Du
authors.forename: Zehan
authors.initials: Z
authors.lastname: Li
authors.forename: Bing
authors.initials: B
authors.lastname: Xue
authors.forename: Takayoshi
authors.initials: T
authors.lastname: Kobayashi
authors.forename: Dongjia
authors.initials: D
authors.lastname: Han
authors.forename: Yuanan
authors.initials: Y
authors.lastname: Zhao
authors.forename: Yuxin
authors.initials: Y
authors.lastname: Leng