Fig. 1: Design of vdW heterostructure cavity.
From: Van der Waals photonic integrated circuit with coherent light generation
a Schematic of ring-shaped heterostructure cavity on silicon oxide/silicon substrate. b Cross-sectional illustration of on-chip integration. Structural parameters of r, h, d, and ho are ring radius, height, width, and silicon oxide thickness, respectively. c Cross-sectional bright-field transmission electron microscopy (TEM) image of vdW heterostructure with inset of zoomed-in high-resolution TEM image of the blue region. False colours indicate the different materials forming the vdW heterostructure. d Scanning electron microscopy (SEM) image of cavity. e Cross-sectional view of the axis-symmetrically simulated electric-field profiles of first-order transverse electric (TE1) whispering gallery modes (WGMs). White dashed line denotes the WS2 position. f Photoluminescence spectrum for ring cavity with multiple TE1 WGMs highlighted by yellow dots. The second-order TE2 modes are spectrally located between TE1 modes.
