On-chip optical isolators constitute an essential building block for photonic integrated circuits (PICs). Here, we experimentally demonstrated a magneto-optical isolator monolithically integrated on silicon featuring 3 dB insertion loss and 40 dB isolation ratio, both of which represent significant improvements over state-of-the-art. The isolator is also fully passive and operates under a simple unidirectional magnetization scheme. Such superior performance is enabled through a three-way combination of a strip-loaded waveguide design, a compositionally optimized chalcogenide glass as the light guiding medium, and low-loss taper structures created via gray -scale lithographic processing. The device represents an important step toward a practical solution for on-chip isolation in PICs.

Broadband supercontinuum (SC) generation requires host material attributes defined by both optical and physical properties and the material’s manufacturability. We review and define the trade-offs in these attributes as applied to fiber or planar film applications based on homogeneous glass property data, and provide a series of examples of how one might optimize such attributes through material compositional and morphology design. As an example, we highlight the role of varying composition, microstructure, and linear/nonlinear optical properties, such as transmittance, refractive index, and the multiphoton absorption coefficient, for a series of novel multicomponent chalcogenide glasses within a model GeSe2-As2Se3-PbSe (GAP-Se) system. We report key optical property variation as a function of composition and form, and discuss how such glasses, suitable for both fiber and planar film processing, could lend themselves as candidates for use in SC generation. We demonstrate the impact of starting glass composition and morphology and illustrate how tailoring composition and form (bulk versus film) leads to significant variation in linear, nonlinear, and dispersive optical property behavior within this system that enables design options that are attractive to optimization of desirable SC performance, based on optical composites.

The size and weight of conventional imaging systems is defined by costly non‐planar lenses and the complex lens assemblies required to minimize optical aberrations. The ability to engineer gradient refractive index (GRIN) optics has the potential to overcome constraints of traditional homogeneous lenses by reducing the number of components in optical systems. Here, an innovative strategy to realize this goal based on monolithic GRIN media created in Ge‐As‐Se‐Pb chalcogenide infrared nanocomposites is presented. A gradient heat treatment to spatially modulate the volume fraction of high refractive index Pb‐rich nanocrystals within a glass matrix is utilized, providing a GRIN profile while maintaining an optical transparency. A first‐ever correlation of material chemistry and microstructure, processing protocol, and optical property modification resulting in a prototype GRIN structure is presented. The integrated approach and mechanistic understanding illustrated by this versatile modification paradigm provides a platform for new optical functionalities in next‐generation imaging applications.

The design of active optical devices integrating second-order nonlinear (SONL) optical responses typically relies on the use of dielectric crystalline materials such as lithium niobate (LN) or semi-conductors such as GaAs. Despite high SONL susceptibilities, these materials present important geometry constrains inherent to their crystalline nature limiting the complexity of the designed photonic systems. Conversely, amorphous materials are versatile optical media compatible with broad platform designs possessing a wide range of optical properties attributable to their composition flexibility. Demonstrated here for the first time in an amorphous inorganic material, we report a magnitude of SONL optical susceptibility (χ (2) =29 pm/V at 1.06 µm) comparable to that of LN single crystal. By using a thermo-electrical imprinting process, fine control of the induced uniaxial anisotropy is demonstrated at the micrometer scale. This work paves the way for the future design of integrated nonlinear

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