This paper discusses Anderson localization, which is the phenomenon where the propagation of diffusive waves is halted in disordered systems. Despite extensive research spanning 40 years, the localization of light in three dimensions has remained elusive, raising questions about whether it actually occurs. The text presents numerical evidence of three-dimensional localization of vector electromagnetic waves occurring within random collections of metallic spheres that overlap, which is in stark contrast to the lack of localization observed in dielectric spheres with refractive indices as high as 10 in air.VIEW NOTEBOOK
This paper presents photonic-crystal surface-emitting lasers (PCSELs) and their potential for creating large-area single-mode lasers. Scaling up PCSELs while maintaining single-mode operation is challenging, and it has impeded progress in achieving very large PCSELs. This scaling challenge arises from the diminishing quality-factor (Q) contrast between the fundamental laser mode and higher-order modes as the lateral size of the crystal increases. The text introduces the concept of bound states in the continuum (BIC), which can address this challenge.
This paper introduces a novel approach using Graph Neural Networks (GNN). This GNN architecture is designed to learn and model electromagnetic scattering and can be applied to metasurfaces of arbitrary sizes. Importantly, it considers the coupling between scatterers. As a result, this approach allows for the rapid calculation of near-fields for metasurfaces. Additionally, the approach can also be used for the inverse design of large metasurfaces, offering a versatile tool for electromagnetic field modeling and design.
In this paper, the authors propose a programmable photonic crystal cavity array and demonstrate near-complete control over the spatiotemporal properties of a 64 resonator, two-dimensional spatial light modulator with nanosecond- and femtojoule-order switching. Simultaneously operating wavelength-scale modes near the space–bandwidth and time–bandwidth limits, this work opens a new regime of programmability at the fundamental limits of multimode optical control.
In this work, the authors present a design for planar photonic topological waveguides characterized by low index contrast. Notably, they create these waveguides using polymeric materials through three-dimensional printing, allowing for rapid device fabrication. To assess the topological protection of these waveguides, they employ high-speed finite-difference time-domain simulations, particularly focusing on “omega” shaped bent topological waveguides.
Metalenses for optical beam manipulation have a significant impact in many exciting applications due their compact, planar geometry and ease of fabrication. However, the enormous physical size of metalenses relative to the optical wavelength provides a barrier to performing accurate simulations in a reasonable time frame. In principle, full-wave simulation techniques, such as the finite-difference time-domain (FDTD) method, are ideal for metalens modeling as they give an accurate picture of the device performance. However, when applied using traditional computing platforms, this approach is infeasible for large-diameter metalenses and requires hours and days to simulate even devices of modest size. To alleviate these issues, the standard approach has been to apply approximations, which typically employ simplified models of the metalens unit cells or ignore coupling between cells, leading to inaccurate predictions. In this Perspective, first, we summarize the current state of the art approaches in simulating large scale, three-dimensional metalenses. Then, we highlight that advances in computing hardware have now created a scenario where the full-wave simulation of large area metalenses is feasible within a reasonable time frame, providing significant opportunities to the field. As a demonstration, we show that a hardware-accelerated FDTD solver is capable of simulating a fully 3D, large area metalens of size 100λ × 100λ, including the focal length, in under 5 min. The application of hardware-accelerated, full-wave simulation tools to metalens simulation should have a significant impact in the metalens field and the greater photonics community. The authors wish to acknowledge the help of Lei Zheng for technical assistance. All authors have a financial interest in Flexcompute, Inc., which developed the Tidy3D solver used in this work.VIEW NOTEBOOK