title: Design of a GaP/Si composite waveguide for CW terahertz wave generation via difference frequency mixing.
abstract: We design a GaP/Si composite waveguide to achieve efficient terahertz (THz) wave generation under collinear phase-matched difference frequency mixing (DFM) between near-infrared light sources. This waveguide structure provides a strong mode confinement of both near-infrared sources and THz wave, resulting in an efficient mode overlapping. The numerical results show that the waveguide can produce guided THz wave (5.93 THz) with a power conversion efficiency of 6.6×10(-4)  W(-1). This value is larger than previously obtained with the bulk GaP crystal: 0.5×10(-9)  W(-1) [J. Lightwave Technol.27, 3057 (2009)]. Our proposed composite waveguide can be achieved by bridging the telecom wavelength and THz frequency region.
authors.forename: Kyosuke
authors.initials: K
authors.lastname: Saito
authors.forename: Tadao
authors.initials: T
authors.lastname: Tanabe
authors.forename: Yutaka
authors.initials: Y
authors.lastname: Oyama