From high- to low-contrast: the role of asymmetries in dielectric gratings supporting bound states in the continuum.

One-dimensional sub-wavelength gratings are versatile photonic platforms supporting diverse resonances, including symmetry-protected bound states in the continuum. However, practical access to these bound modes relies on their quasi-bound form, which necessitates the introduction of perturbations in either geometry or material properties. Despite having a large, finite quality factor, quasi-bound modes retain their characteristically strong field confinement.

Harnessing the Natural Resonances of Time-Varying Dispersive Interfaces.

Space-time modulation of electromagnetic parameters offers novel exciting possibilities for advanced field manipulations. In this study, we explore wave scattering from a time-varying interface characterized by a Lorentz-type dispersion with a steplike temporal variation in its parameters. Our findings reveal a new process: an unconventional frequency generation at the natural resonances of the system.

Identity-Driven Targeted Violence in a College Setting: An Overview of Prevalence and Behavioral Responses.

Background: Online and offline identity-driven harassment disproportionately affects minoritized college students, contributing to poorer academic performance and attrition. Because victims are often hesitant to formally report incidents, additional research is needed to understand the genuine prevalence of these experiences as well as the responses victims engage in following the incidents.

Methods: A large undergraduate sample ( = 2000) from a Midwestern university responded to an anonymous survey assessing the frequency of identity-driven behavior occurring on-campus and beyond, in addition to how they responded to harassment.

Nonlinear spin-orbit coupling in optical thin films.

Tunable generation of vortex beams holds relevance in various fields, including communications and sensing. In this paper, we demonstrate the feasibility of nonlinear spin-orbit interactions in thin films of materials with second-order nonlinear susceptibility. Remarkably, the nonlinear tensor can mix the longitudinal and transverse components of the pump field.

Harmonic generation from silicon membranes at visible and ultraviolet wavelengths.

Nonlinear silicon photonics offers unique abilities to generate, manipulate and detect optical signals in nano-devices, with applications based on field localization and large third order nonlinearity. However, at the nanoscale, inefficient nonlinear processes, absorption, and the lack of realistic models limit the nano-engineering of silicon. Here we report measurements of second and third harmonic generation from undoped silicon membranes.