%0 Journal Article
%T Angular Dependence of the Second Harmonic Generation Induced by Femtosecond Laser Irradiation in Silica-Based Glasses: Variation with Writing Speed and Pulse Energy
%A Jing Cao
%A Bertrand Poumellec
%A Fran£¿ois Brisset
%A Anne-Laure Helbert
%A Matthieu Lancry
%J World Journal of Nano Science and Engineering
%P 96-106
%@ 2161-4962
%D 2015
%I Scientific Research Publishing
%R 10.4236/wjnse.2015.53012
%X To control second harmonic generation (SHG) in silica-based glasses is crucial for fabricating photonic devices, such as frequency doubling waveguides. Here, we investigated SHG of laser induced nonlinear optical crystals in silica-based glasses, according to writing speed and pulse energy. We observed two regions with different probing laser polarization angular dependence: a) a well-defined cosine-like curve with period of 180¡ã at low pulse energy (0.8 ¦ÌJ) whatever the writing speed or at high pulse energy (1.4 ¦ÌJ) with high writing speed (25 ¦Ìm/s). This is accounted for by a well-defined texture for the nano crystals with their polar axis oriented perpendicular to the writing laser polarization; and b) a double cosine-like curve revealing a second texture of the crystals at high pulse energy (1.4 ¦ÌJ) with low writing speed (5 ¦Ìm/s) and with the polar axis oriented closer parallel to the writing laser polarization. Therefore, a SHG dependence on probing laser polarization angle may show high contrast by a correct choice of the writing speed and pulse energy. These results pave the way for elaboration of nonlinear optical devices.
%K Nonlinear Optical Crystal
%K Glass Ceramics
%K Direct Writing
%K Ultrafast Processes
%K Waveguide
%U http://www.scirp.org/journal/PaperInformation.aspx?PaperID=59915