Space-selective precipitation of functional crystals in glass by using a high repetition rate femtosecond laser

• Published in: Chemical physics letters Vol. 443; no. 4; pp. 253 - 257
• Main Authors: Dai, Ye, Zhu, Bin, Qiu, Jianrong, Ma, Hongliang, Lu, Bo, Yu, Bingkun
• Format: Journal Article
• Language: English
• Published: Elsevier B.V 06.08.2007
• ISSN: 0009-2614; 1873-4448
• DOI: 10.1016/j.cplett.2007.06.076

Nonlinear optical crystals Sr 2TiSi 2O 8 can be written arbitrarily in a stoichiometric SrO–TiO 2–SiO 2 glass by using a high repetition rate femtosecond laser. The pictogram shows the Raman spectra of the laser-induced crystals (curve A) and the unirradiated glass (curve B). The inset shows the cross-polarized microscope images of the measured spot positions. The input power for inducing Sr 2TiSi 2O 8 crystals was 850 mW. Nonlinear optical crystals Sr 2TiSi 2O 8 are written arbitrarily in a stoichiometric SrO–TiO 2–SiO 2 glass by using a high repetition rate femtosecond laser. The mechanism of nucleation and subsequent crystal growth is assumed to the thermal accumulation effect and the laser-induced reduction of Ti 4+ to Ti 3+. Additionally, the threshold time for inducing crystal formation decreases, while the corresponding dot size increases with increasing laser power. The threshold variation is also discussed according to the mechanism of nucleation. We suggest that this technique can be used in light-wave switching, 3D optical memory and laser display.