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In the exploitation of nanozymes possessing intrinsic enzyme-like activities for cancer therapy, minor focus has been devoted to plasmonic nanostructures with localized surface plasmon resonance (LSPR)-driven properties. Here, we report the application of unique peroxidase-mimicking plasmonic photo-nanozymes coupling tumor-microenvironment-responsive reactive oxygen species generation with photothermal effect for effective combinatorial therapy. The well-defined anisotropic photo-nanozyme is synthesized by selectively depositing Pd nanoparticles on the tips of gold nanobypyramids. Intrinsic peroxidase-like properties with 1.5-fold-activity enhancement under photoexcitation are ascribed to a Pd-induced hot electrons/holes separation with efficient H2O2 decomposition. The LSPR-induced photocatalytic/photothermal combinatorial effects are remarkably enhanced upon H2O2 addition, critically suppressing the cell survival rate under near-infrared light. An effective decomposition of cell-signaling H2O2 additionally reveals prominent expression hindrance of vascular endothelial growth factor and hypoxia-inducible factor 1α. Our seminal findings uncover an interrelation between LSPR-induced phenomena and biomimetic fingerprints, valuable to overcome the shortcomings of conventional photodynamic therapy.

The field of flat optics that uses nanostructured, so-called metasurfaces, has seen remarkable progress over the last decade. Chalcogenide phase-change materials (PCMs) offer a promising platform for realizing reconfigurable metasurfaces, as their optical properties can be reversibly tuned. Yet, demonstrations of phase-change metalenses to date have employed material compositions such as Ge2Sb2Te5, which show high absorption in the visible to near-IR wavelengths particularly in their crystalline state, limiting the applicability. Here, by using a low-loss PCM Sb2Se3, for the first time, active polarization-insensitive phase-change metalenses at near-IR wavelengths with comparable efficiencies in both material states are shown. An active metalens with a tunable focusing intensity of 95% and a focusing efficiency of 23% is demonstrated. A varifocal metalens is then demonstrated with a tunable focal length from 41 to 123 µm with comparable focusing efficiency (5.7% and 3%). The ultralow-loss nature of the material introduces exciting new possibilities for optical communications, multi-depth imaging, beam steering, optical routing, and holography.

Wavelength and polarization are two fundamental properties of light within which information can be encoded and (de)multiplexed. While wavelength-selective systems have widely proliferated, polarization-addressable active photonics has not seen notable progress, primarily because tunable and polarization-selective nanostructures have been elusive. Here, we introduce hybridized-active-dielectric (HAD) nanowires to achieve polarization-selective tunability. We then demonstrate the ability to use polarization as a parameter to selectively modulate the conductance of individual nanowires within a multi-nanowire system. By using polarization as the tunable vector, we show matrix-vector multiplication in a nanowire device configuration. While our HAD nanowires use phase-change materials as the active material, this concept is readily generalized to other active materials hybridized with dielectrics and thus has the potential in a broad range of applications from photonic memories and routing to polarization-multiplexed computing.

In this work, we propose a novel architecture for building a robust integrated photonic neuromorphic accelerator based on a crossbar array design. Our architecture is based on an asymmetric multimode Y-coupler. A Y-coupler has the inherent benefit of high fabrication tolerance and broad optical bandwidth. From simulations, we show that our proposed Y-coupler has high coupling efficiency. Using modal decomposition analysis of our coupler, we numerically estimate the energy efficiency performance of a large-scale photonic network and show a 10% improvement in energy efficiency for large-scale photonic networks with high fabrication tolerance and broadband application and a small footprint.

In this study, we propose reconfigurable metasurfaces based on a low-loss chalcogenide phase-change material, antimony triselenide (Sb2Se3). The developed metasurfaces exhibit tunable focusing properties along with transformation of the Sb2Se3 between amorphous and crystalline states.

Ever-increasing processing and storage requirements steer us towards co-integration of electronics and photonics. Here, we demonstrate waveguide-integrated plasmonic memory and computing elements by employing phase-change materials with reconfigurable properties and dual electro-optic functionality.