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We present a framework for an arbitrary polarization state generator exploiting Berry’s phase through a cascade of in-plane and out-of-plane silicon strip waveguides. We establish two criteria required for a passive device to achieve 90° polarization rotation, and derive explicit equations to satisfy the criteria. The results define regions within the parameter space where active tuning of the polarization state is possible over the entire Poincaré sphere. We use numerical modeling to show ±30 dB tuning of the polarization extinction ratio between the quasi-transverse electric and magnetic modes for a range of devices with deflection angles ranging from 5° to 45°, and modal birefringence from 0 to 0.05. We envision control of optical polarization on the chip-scale in integrated waveguides for communications, sensing, and computing applications.

Sub-micrometer-thick lithium niobate on an insulator is a promising integrated photonic platform that provides optical field confinement and optical nonlinearity useful for state-of-the-art electro-optic modulators and wavelength converters. The fabrication of lithium niobate on insulator on a silicon substrate through ion slicing is advantageous for electronic-photonic integration but is challenging because of debonding and cracking due to the thermal expansion coefficient mismatch between silicon and lithium niobate. In this work, the fabrication of thin film lithium niobate on insulator on a silicon handle wafer is achieved, informed by structural modeling, and facilitated by accommodating for dissimilar wafer bows using a bonding apparatus. Structural finite element analysis of strain energy and stress, due to thermal expansion coefficient mismatch at elevated temperatures, is conducted. High strain energies and stresses that result in debonding and cracking, respectively, are studied through modeling and reduced by selecting optimized substrate thicknesses followed by an experimental technique to bond substrates with dissimilar bows. A lithium niobate thin film with a thickness of 800 nm is successfully transferred to an oxidized silicon wafer with a root mean square surface roughness of 5.6 nm.

We utilize out-of-plane waveguides exhibiting Berry’s phase to generate guided light carrying angular momentum. The normalized output orbital and spin angular momenta are computed to be 0.85 and 0.15 per photon, respectively, at 1550 nm wavelength.

We report enhanced photoluminescence in the telecommunications wavelength range in ring resonators patterned in hydrogenated amorphous silicon thin films deposited via low-temperature plasma enhanced chemical vapor deposition. The thin films exhibit broadband photoluminescence that is enhanced by up to 5 dB by the resonant modes of the ring resonators due to the Purcell effect. Ellipsometry measurements of the thin films show a refractive index comparable to crystalline silicon and an extinction coefficient on the order of 0.001 from 1300 nm to 1600 nm wavelengths. The results are promising for chip-scale integrated optical light sources.