Field trial assessing the antimicrobial decontamination efficacy of gaseous ozone in a public bus setting.

The widespread COVID-19 pandemic caused by the Severe Acute Respiratory Syndrome Coronavirus-2 (SARS-CoV-2) necessitated measures aimed at preventing the spread of SARS-CoV-2. To mitigate the risk of fomite-mediated transmission, environmental cleaning and disinfection regimes have been widely implemented. However, conventional cleaning approaches such as surface wipe downs can be laborious and more efficient and effective disinfecting technologies are needed.

All-Glass, Large Metalens at Visible Wavelength Using Deep-Ultraviolet Projection Lithography.

Metalenses, planar lenses realized by placing subwavelength nanostructures that locally impart lenslike phase shifts to the incident light, are promising as a replacement for refractive optics for their ultrathin, lightweight, and tailorable characteristics, especially for applications where payload is of significant importance. However, the requirement of fabricating up to billions of subwavelength structures for centimeter-scale metalenses can constrain size-scalability and mass-production for large lenses. In this Letter, we demonstrate a centimeter-scale, all-glass metalens capable of focusing and imaging at visible wavelength, using deep-ultraviolet (DUV) projection stepper lithography.

Using the Belinfante momentum to retrieve the polarization state of light inside waveguides.

Current day high speed optical communication systems employ photonic circuits using platforms such as silicon photonics. In these systems, the polarization state of light drifts due to effects such as polarization mode dispersion and nonlinear phenomena generated by photonic circuit building blocks. As the complexity, the number, and the variety of these building blocks grows, the demand increases for an in-situ polarization determination strategy.

Adaptive metalenses with simultaneous electrical control of focal length, astigmatism, and shift.

Focal adjustment and zooming are universal features of cameras and advanced optical systems. Such tuning is usually performed longitudinally along the optical axis by mechanical or electrical control of focal length. However, the recent advent of ultrathin planar lenses based on metasurfaces (metalenses), which opens the door to future drastic miniaturization of mobile devices such as cell phones and wearable displays, mandates fundamentally different forms of tuning based on lateral motion rather than longitudinal motion.

Large area metalenses: design, characterization, and mass manufacturing.

Optical components, such as lenses, have traditionally been made in the bulk form by shaping glass or other transparent materials. Recent advances in metasurfaces provide a new basis for recasting optical components into thin, planar elements, having similar or better performance using arrays of subwavelength-spaced optical phase-shifters. The technology required to mass produce them dates back to the mid-1990s, when the feature sizes of semiconductor manufacturing became considerably denser than the wavelength of light, advancing in stride with Moore's law.

High efficiency near diffraction-limited mid-infrared flat lenses based on metasurface reflectarrays.

We report the first demonstration of a mid-IR reflection-based flat lens with high efficiency and near diffraction-limited focusing. Focusing efficiency as high as 80%, in good agreement with simulations (83%), has been achieved at 45° incidence angle at λ = 4.6 μm.

Parallel Polarization State Generation.

The control of polarization, an essential property of light, is of wide scientific and technological interest. The general problem of generating arbitrary time-varying states of polarization (SOP) has always been mathematically formulated by a series of linear transformations, i.e.

Controlled steering of Cherenkov surface plasmon wakes with a one-dimensional metamaterial.

In the Cherenkov effect a charged particle moving with a velocity faster than the phase velocity of light in the medium radiates light that forms a cone with a half angle determined by the ratio of the two speeds. Here, we show that by creating a running wave of polarization along a one-dimensional metallic nanostructure consisting of subwavelength-spaced rotated apertures that propagates faster than the surface plasmon polariton phase velocity, we can generate surface plasmon wakes, a two-dimensional analogue of Cherenkov radiation. The running wave of polarization travels with a speed determined by the angle of incidence and the photon spin angular momentum of the incident radiation.

Generation of two-dimensional plasmonic bottle beams.

By analogy to the three dimensional optical bottle beam, we introduce the plasmonic bottle beam: a two dimensional surface wave which features a lattice of plasmonic bottles, i.e. alternating regions of bright focii surrounded by low intensities.