Optical generation of terahertz and second-harmonic light in plasma-activated silicon nanophotonic structures

Plasma-activated silicon structures exhibit symmetry broken surfaces through chemical surface modification leading to a considerable second-order nonlinear optical response. This nonlinear response is demonstrated in second-harmonic and difference frequency generation measurements including the generation of terahertz radiation in silicon photonic nanowires using telecom wavelength excitation pulses. (C) 2010 American Institute of Physics. [doi:10.1063/1.3503586]