Color arrestor pixels for high-fidelity, high-sensitivity imaging sensors.

Silicon is the dominant material in complementary metal-oxide-semiconductor (CMOS) imaging devices because of its outstanding electrical and optical properties, well-established fabrication methods, and abundance in nature. However, with the ongoing trend toward electronic miniaturization, which demands smaller pixel sizes in CMOS image sensors, issues, such as crosstalk and reduced optical efficiency, have become critical. These problems stem from the intrinsic properties of Si, particularly its low absorption in the long wavelength range of the visible spectrum, which makes it difficult to devise effective solutions unless the material itself is changed.

Universal Metasurfaces for Complete Linear Control of Coherent Light Transmission.

Recent advances in metasurfaces and optical nanostructures have enabled complex control of incident light with optically thin devices. However, it has thus far been unclear whether it is possible to achieve complete linear control of coherent light transmission, that is, independent control of polarization, amplitude, and phase for both input polarization states, with just a single, thin nanostructure array. Here, it is proved possible, and a universal metasurface is proposed, a bilayer array of high-index elliptic cylinders that possesses a complete degree of optical freedom with fully designable chirality and anisotropy.

Spectrally sharp metasurfaces for wide-angle high extinction of green lasers.

In optical nanostructures used as artificial resonance-based color filters, there is unfortunate universal trade-off between spectral sharpness and angular tolerance as well as maximum extinction. We rigorously derive the maximum performance bounds of wavelength-rejection filters realized by single-layer plasmonic metasurfaces with a dominant resonance and weak near-field coupling, and propose a multi-layer approach to overcome these single-layer limits and trade-offs. We also present a realistic example that has a narrow full-width-at-half-maximum bandwidth of 24 nm with 10 dB extinction at 532 nm with good angular tolerance up to 60°.

Near-atomically flat, chemically homogeneous, electrically conductive optical metasurface.

Metasurfaces, or two-dimensional arrays of subwavelength-scale structures, can exhibit extraordinary optical properties. However, typical metasurfaces have a bumpy surface morphology that may restrict their practical applications. Here, we propose and demonstrate an optical metasurface that is composed of a thin metallic film, with hidden dielectric structures underneath, and a metal back mirror layer.

Ultralarge Area Sub-10 nm Plasmonic Nanogap Array by Block Copolymer Self-Assembly for Reliable High-Sensitivity SERS.

Effective surface enhancement of Raman scattering (SERS) requires strong near-field enhancement as well as effective light collection of plasmonic structures. To this end, plasmonic nanoparticle (NP) arrays with narrow gaps or sharp tips have been suggested as desirable structures. We present a highly dense and uniform Au nanoscale gap array enabled by the customized design of NP shape and arrangement employing block copolymer self-assembly.