Fig. 2
From: Heterogeneous integration for on-chip quantum photonic circuits with single quantum dot devices
Nanophotonic design. a Left panel: electric field distribution for the fundamental TE GaAs supermode of the waveguide stack in Fig. 1c, with dimensions specified in the main text. Center panel: electric field distribution across the mode-transformer cross-section, for a GaAs mode launched at z = 0. At z ≈ 10 μm, the GaAs and Si3N4 guides are phase-matched, and power is efficiently transferred from the top GaAs to the bottom Si3N4 guide. Right panel: fundamental TE mode of the Si3N4 waveguide at the end of the mode transformer. b Coupling efficiency (β), as a function of GaAs width and emission wavelength, of photons emitted by a dipole located at x = 0 and 74 nm below the top surface, into the GaAs waveguide mode traveling in either the +z or −z direction. c Modal power conversion efficiency from the GaAs mode into the Si3N4 mode in (a) as a function of wavelength
