Photovariation of grating-assisted coupling of terahertz waves into a silicon waveguide
Résumé
Using terahertz (THz) time-domain spectroscopy, we study the coupling of THz waves into a silicon waveguide by means of a grating coupler. We vary the efficiency of the coupling coefficient for selected frequencies up to 20% in amplitude (40% in intensity) by generating photocarriers in the silicon material through illumination of the waveguide with white light. The experimental data are well fitted using the differential method to model the grating diffraction.