Visualization of the frequency-doubling space-charge region in thermally poled fused silica: measurement technique and model

A large second-order nonlinearity is induced in fused silica glass under electrical poling at elevated temperature (thermal poling). This technique has been applied in both bulk fused silica and optical fibers. In optical fibers, this technique has been used to demonstrate an electrooptically active fiber (for switching or modulation) as well as quasi-phase matching by periodic poling.