Fig. 4: Heterostructure optimization.
a, Theoretical acoustic gain as a function of drift field for an acoustoelectric equivalent circuit model. The red dashed line indicates the synchronous point where vd = va, the dashed blue line indicates the maximum gain value, and the green line indicates the maximum gain slope. b, Contour plot of the modelled k2 value as a function of LiNbO3 film thickness and acoustic wavelength. c, Theoretical maximum gain slope and modelled k2 value as a function of acoustic wavelength for a LiNbO3 film thickness of 5 μm. The inset shows a plot of the theoretical gain slope as a function of σt. d, Plot of the theoretical Rth as a function of substrate thermal conductivity. The inset shows the computed Rth for a heat-transfer finite element method model of the In0.53Ga0.47As–LiNbO3–silicon heterostructure as a function of LiNbO3 thickness. In these models, the In0.53Ga0.47As layer serves as the heat source, with a thickness of 50 nm, length of 500 µm, and width of 50 µm.
