Densely-aligned void arrays of the length of hundreds of micrometers are fabricated in SrTiO3 crystal by tightly focusing multiple femtosecond (fs) pulses and fixing the focal point at a certain depth of SrTiO3 crystal without translation. The effect of the laser energy and the laser irradiation time as the well as entrance crystal plane on the induced structures is investigated. It is possible to control these factors to achieve the desirable void strings. This kind of self-fabrication method combined with the high linear refractive index of SrTiO3 (2.30 at 800 nm) largely extends the fabrication scope which is generally limited by the short working distance of the high numerical aperture (NA) objective lens in scanning fabrication mode. The possible formation mechanism is also discussed.
© 2007 Chinese Optics Letters
(160.4670) Materials : Optical materials
(190.4400) Nonlinear optics : Nonlinear optics, materials
(210.4810) Optical data storage : Optical storage-recording materials
(220.4000) Optical design and fabrication : Microstructure fabrication
(230.4000) Optical devices : Microstructure fabrication
Juan Song, Haiyi Sun, Xinshun Wang, Jian Xu, Jianrong Qiu, and Zhizhan Xu, "Self-organized void strings induced in SrTiO3 crystal by a femtosecond laser," Chin. Opt. Lett. 5, S218-S221 (2007)