Advanced Metamaterials Special Webinar: David Cumming , Metamaterials for Imaging and Polarimetry

Metamaterials offer advanced capabilities for manipulating light and sound, enabling ultrathin optics and enhanced functionality in imaging and polarimetry. This work explores the design, fabrication, and application of plasmonic filters and metasurfaces across visible, infrared, and terahertz wavelengths. Plasmonic filters, based on arrays of holes or elliptical structures in thin metal films, demonstrate enhanced extraordinary transmission (up to twice previous designs) with good angular dispersion control and a wide color gamut, facilitating integration onto CMOS focal plane arrays. This enables single-processing step color filter integration and advanced polarization-sensitive imaging, including secure information encoding. Color imaging on single-photon avalanche diode (SPAD) arrays is demonstrated, with 64x64 pixel data reconstructed to 512x512 resolution, aiming for combined color, polarization, and 3D depth ranging. Beyond visible applications, ultralightweight metalenses designed from dielectric meta-atoms achieve diffraction-limited resolution (λ/2 for an F/1 lens at 1064 nm) for earth observation. Terahertz metamaterials are developed for multispectral filtering (visible to terahertz) and bolometric imaging, successfully detecting hidden objects. Furthermore, a terahertz metasurface axicon is demonstrated to generate Bessel beams with rotating polarization, enabling non-contact ellipsometry for precise refractive index characterization of dielectric materials like HDPE. These developments highlight the versatility of metamaterials for highly integrated, multi-functional imaging and sensing systems. Advanced Metamaterials Special Webinar: David Cumming Metamaterials for Imaging and Polarimetry Metamaterials enable the precise manipulation of the phase and polarisation state of light across large surfaces. Unlike traditional optics they are physically thin and lightweight, lending themselves to applications such as space technology where reduction in payload is a major advantage. Furthermore, they offer the opportunity to integrate multiple optical functions into a single component offering further benefits to cost and weight reduction. In this talk I will present results on metamaterials for applications in the visible through to terahertz spectral regions. The talk will include a discussion of work on RGB filtering for advanced digital imaging, including results on colour image reconstruction using single photon avalanche detectors (SPADs). I will also present work on polarimetry in the terahertz band using axiconic structures and the design of metalenses for IR applications.