We report the formation of inverted microstructures inside glasses after femtosecond laser irradiation by tuning the refractive index contrast between the immersion liquid and the glass sample. By using water as well as 1- bromonaphthalene as immersion liquids, microstructures with similar shape but opposite directions are induced after femtosecond laser irradiation. Interestingly, the elemental distribution in the induced structures is also inverted. The simulation of laser intensity distribution along the laser propagation direction indicates that the interfacial spherical aberration effect is responsible for the inversion of microstructures and elemental distribution.
© 2011 Optical Society of America
Original Manuscript: February 14, 2011
Revised Manuscript: April 25, 2011
Manuscript Accepted: April 26, 2011
Published: June 1, 2011
Fangfang Luo, Juan Song, Xiao Hu, Haiyi Sun, Geng Lin, Huaihai Pan, Ya Cheng, Li Liu, Jianrong Qiu, Quanzhong Zhao, and Zhizhan Xu, "Femtosecond laser-induced inverted microstructures inside glasses by tuning refractive index of objective’s immersion liquid," Opt. Lett. 36, 2125-2127 (2011)