Fig. 1: 3D representation of the modulator selectively covered by ferroelectric nematic liquid crystals (FN-LC) as an organic electro-optic (OEO) cladding.
a 80-nm-wide fingers are used to carry the RF signals and alignment field (Ealign) to an area as close as df−c = 100 nm away from the Wc = 300 nm-wide core. This design optimizes the overlap integral (Γ) between the optical and electrical fields while minimizing optical loss. An external light source, either through a grating coupler or a photonic wire bond (PWB), feeds the optical signal. The waveguides are identified by a 2 μm trench that surrounds them. A positive-tone e-beam resists the device. Inset: an illustrative chemical structure and polar order of dipolar constituents of the FN-LC phase, where n denotes the molecular director, P is the polarization, and D−π−A is the donor-bridge-acceptor electronic structure. b The layer stack-up of the Mach-Zehnder Modulator (MZM) consists of two finger-loaded strip (FLS) waveguides in each arm. c A zoomed-in diagram of the FLS waveguide with infiltrated FN-LC ordered along Ealign.
