We present a promising coupling device, namely, a terahertz (THz) planar photonic crystal (PhC) lens based on the effective refractive-index contrast between the PhC and the surrounding unpatterned area. Three-dimensional finite-difference time-domain calculations show a 90% power transfer from a 100-µm silicon waveguide to a 10-µm waveguide, and 45% coupling efficiency is confirmed experimentally. These results demonstrate the utility of the PhC lens as an effective approach to coupling into PhC THz circuits.
© 2005 Optical Society of America
Chunchen Lin, Caihua Chen, Ahmed Sharkawy, Garrett J. Schneider, Sriram Venkataraman, and Dennis W. Prather, "Efficient terahertz coupling lens based on planar photonic crystals on silicon on insulator," Opt. Lett. 30, 1330-1332 (2005)