Second harmonic generation in poled tungsten tellurite glasses

Second harmonic signals have been successfully generated in thermally poled 85% TeO 2 -15% WO 3 glasses. Thermal poling of these glasses was undertaken at various temperatures and heating times using a voltage of 4.5 k V. The sample thickness was 500 μm. Second harmonic generation (SHG) in the poled glasses was analysed using the Maker fringes technique. After optimisation of the poling conditions (T=280°C, t=1 h), high X (2) values (about 1.6 pm/V) were obtained. It was demonstrated that this thermal poling treatment has generated optically nonlinear zones on the anodic surface. The thickness of the surface layer given a SHG was thin (5.22 μm), as classically observed with tellurite glasses. The possible reorientation, under electric field, of the glass structural entities could be the origin of such second order nonlinear properties.