Topology Optimized Multi-layered Meta-optics

We propose a general topology optimization framework for metasurface inverse design that can automatically discover highly complex multi-layered meta-structures with increased functionalities. In particular, we present topology-optimized multi-layered geometries exhibiting angular phase control, including a single-piece nanophotonic metalens with angular aberration correction as well as an angle-convergent metalens that focuses light onto the same focal spot regardless of the angle of incidence

High-efficiency chiral meta-lens

We present here a compact metasurface lens element that enables simultaneous and spatially separated imaging of light of opposite circular polarization states. The design overcomes a limitation of previous chiral lenses reliant on the traditional geometric phase approach by allowing for independent focusing of both circular polarizations without a 50% efficiency trade-off. We demonstrate circular polarization-dependent imaging at visible wavelengths with polarization contrast greater than 20dB and efficiencies as high as 70%

Matlab code for virtual focal length

Matlab code for virtual focal lengt

Tyndall Windows: Tunable Scattering of Disordered Solid–Liquid Matching Mixtures

We explain and explore sharp optical diffusion modulations of solid–liquid matching mixtures. The technique is based on sole refractive index modulation mismatch of optically matching materials at different states. This enables basic materials such as glass-based mixtures to obtain a sharp window of transparency at a desired condition. Our demonstration indicates over 3 orders of magnitude optical transmission modulation with 0.03 thermally induced modulation of the refractive index mismatch. The narrow full width at half maximum of this diffusion modulation is the result of Tyndall scattering of densely packed irregular particles that is not fully explainable by Mie theory. Such mixtures can be used as tunable phantoms and have applications in optofluidics, rheology, and cytometry

Meta-Lens Doublet in the Visible Region

Recently, developments in meta-surfaces have allowed for the possibility of a fundamental shift in lens manufacturingfrom the century-old grinding technology to nanofabricationopening a way toward mass producible high-end meta-lenses. Inspired by early camera lenses and to overcome the aberrations of planar single-layered meta-lenses, we demonstrate a compact meta-lens doublet by patterning two metasurfaces on both sides of a substrate. This meta-lens doublet has a numerical aperture of 0.44, a focal length of 342.5 μm, and a field of view of 50° that enables diffraction-limited monochromatic imaging along the focal plane at a wavelength of 532 nm. The compact design has various imaging applications in microscopy, machine vision, and computer vision