Second-Order Optical Nonlinearity in Silicon Waveguides:Inhomogeneous Stress …

The lack of a dipolar second-order susceptibility (χ (2) ) in silicon due to the centrosymmetry of its diamond lattice usually inhibits effi cient second-order nonlinear optical processes in the silicon bulk. Recently, the deposition of stressed silicon nitride layers and the corresponding inhomogeneous strain in silicon lead to the demonstration of second harmonic generation and electrooptic…