Second-harmonic imaging of poled silica waveguides

Electric-field poled silica-based waveguides are characterized by measureme nts of second-harmonic generation (SHG) and of the linear electro-optic eff ect (LEO). A SHG scanning technique allowing for high-resolution imaging of poled devices is demonstrated. Scans along the direction of the poling fie ld show that the second-order optical nonlinearity is located near the inte rface between differently doped glass layers. Both SHG and LEO measurements indicate that the ratio between the main elements of the second-order nonl inear optical susceptibility tensor, chi(33)((2)) and chi(31)((2)), is sign ificantly smaller than three. (C) 2000 American Institute of Physics. [S000 3-6951(00)03301-5].