Author(s)

Jing Cao, Bertrand Poumellec, François Brisset, Anne-Laure Helbert, Matthieu Lancry

Institut de Chimie Moléculaire et des Matériaux d’Orsay (ICMMO), CNRS-Université Paris Sud, Université Paris Saclay, Bât.420, Campus Orsay, 91405 Orsay, France.

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° at low pulse energy (0.8 μJ) whatever the writing speed or at high pulse energy (1.4 μJ) with high writing speed (25 μm/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 μJ) with low writing speed (5 μm/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.

Nonlinear Optical Crystal, Glass Ceramics, Direct Writing, Ultrafast Processes, Waveguide

Cao, J. , Poumellec, B. , Brisset, F. , Helbert, A. and Lancry, M. (2015) Angular Dependence of the Second Harmonic Generation Induced by Femtosecond Laser Irradiation in Silica-Based Glasses: Variation with Writing Speed and Pulse Energy. World Journal of Nano Science and Engineering, 5, 96-106. doi: 10.4236/wjnse.2015.53012.