Fig. 8: Numerical modeling of electro-optic coupling.
From: Lithium niobate photonic-crystal electro-optic modulator
a Schematic of half of the cross-section of the EOM structure. “Gap” denotes the spacing between the gold electrode and the LN cavity, and “tw” denotes the thickness of the waveguide wing layer. b, c Electro-optic tuning efficiency and optical quality factor of the device as a function of Gap and tw, simulated by the FEM method. The red column represents the parameter design used for the EOMs demonstrated in the main text. The blue column shows another design with broader bandwidth and enhanced electro-optic coupling. The individual column at the left of each plot indicates the case when tw = 0 μm and gap = 2.5 μm, for a device with full surrounding air cladding.
