Asymmetric-coupled Ge/SiGe quantum wells for second harmonic generation at 7.1 THz in integrated waveguides: a theoretical study.

ABSTRACT: We present a theoretical investigation of guided second harmonic generation at THz frequencies in SiGe waveguides embedding n-type Ge/SiGe asymmetric coupled quantum wells to engineer a giant second order nonlinear susceptibility. A characteristic of the chosen material system is the existence of large off-diagonal elements in the χ ² tensor, coupling optical modes with different polarization. To account for this effect, we generalize the coupled-mode theory, proposing a theoretical model suitable for concurrently resolving every second harmonic generation interaction among guide-sustained modes, regardless of which χ ² tensor elements it originates from. Furthermore, we exploit the presence of off-diagonal χ ² elements and the peculiar

SUBMITTER: Talamas Simola E 

PROVIDER: S-EPMC11501687 | biostudies-literature | 2024 Apr

REPOSITORIES: biostudies-literature