Multiresonant Nonlocal Metasurfaces

Abstract

Optical metasurfaces supporting localized resonances have become a versatile platform for shaping the wavefront of light, but their low quality (Q-) factor modes inevitably modify the wavefront over extended momentum and frequency space, resulting in limited spectral and angular control. In contrast, periodic nonlocal metasurfaces have been providing great flexibility for both spectral and angular selectivity but with limited spatial control. Here, we introduce multiresonant nonlocal metasurfaces capable of shaping the spatial properties of light using several resonances with widely disparate Q-factors. In contrast to previous designs, the narrowband resonant transmission punctuates a broadband resonant reflection window enabled by a highly symmetric array, achieving simultaneous spectral filtering and wavefront shaping in the transmission mode. Through rationally designed perturbations, we realize nonlocal flat lenses suitable as compact band-pass imaging devices, ideally suited for microscopy. We further employ modified topology optimization to demonstrate high-quality-factor metagratings for extreme wavefront transformations with large efficiency.

Interactions of Fundamental Mie Modes with Thin Epsilon-near-Zero Substrates

“…A transmittance modulation of the same order of magnitude as in our case was reported using plasmonic metasurfaces over ITO . However, the multiresonant and collective natures of dielectric antennas allow the possibility of designing versatile, dynamic all-optical systems by engineering the interactions of each type of Mie mode with ENZ mode separately . A comprehensive investigation of the nonlinear responses of these samples is beyond the scope of this work and is the subject of future research.…”

“…33 However, the multiresonant and collective natures of dielectric antennas allow the possibility of designing versatile, dynamic all-optical systems by engineering the interactions of each type of Mie mode with ENZ mode separately. 39 A comprehensive investigation of the nonlinear responses of these samples is beyond the scope of this work and is the subject of future research. We note that the speed of modification of the transmittance in our strongly coupled system of a-Si and ITO is at least one order of magnitude higher than the previously reported modification speeds of systems based on bare silicon.…”

Enhancing Photon Throughput of Miniaturized Passive Depth-Detection Cameras via Broadband Dispersion-Engineered Metalenses

“…The aforementioned principle can be applied to nonpolarized light, which facilitates the development of high-throughput single-lens passive depth detection cameras . Additionally, nonlocal metasurfaces provide a versatile approach to manipulating light, which enables advanced dispersion engineering. − The combination of PSF and an advanced dispersion engineering method holds the potential for multidimensional perception imaging that exceeds the capabilities of traditional optical components.…”

Realizing Minimally Perturbed, Nonlocal Chiral Metasurfaces for Direct Stokes Parameter Detection

“…Meanwhile, in recent years, there has been growing interest in the development of nonlocal metasurfaces. Nonlocal metasurfaces have the ability to manipulate phase, wavefronts, and polarization of light in a relatively narrow spectral band by inducing collective oscillations of the constituent units over the supra-wavelength scale, in contrast to local metasurfaces which are operated by spatially localized resonances and have limited Q-factors. − Following this, recently developed nonlocal chiral metasurfaces support the chiral resonance with strong CD and a high-Q factor, potentially offering a solution to realize chiral metamaterials with enhanced light–matter interaction at a narrow spectral range. − Such nonlocal chiral metasurfaces provide potential applications to chiral emission, nonlinear optics, and optical communications with benefits over broadband ones in the fine-tuning of optical information within a limited bandwidth. ,, One of the common and recent approaches to realizing nonlocal chiral metasurfaces is to induce quasi-bound states in the continuum (q-BIC) by designing the geometry to be broken mirror symmetry. − Examples of these include the multi-perturbations in a double-layered metasurface , and out-of-plane symmetry breaking using structures with different heights. − More recently, nonlocal chiral metasurfaces in optical frequency were successfully demonstrated by designing and fabricating the in-plane chiral nanostructures at the subwavelength scale. , Despite the progresses, the underlying physics and design rules of nonlocal chiral metasurfaces are not fully revealed compared to the case of local chiral metasurfaces explored for the last decades. In addition, it is still challenging to achieve high-Q stokes parameters detection since the precise and consistent-sized fabrication of the various nanogeometries for targeted S parameters and wavelength with high-Q factor is still elusive and thus has not been demonstrated.…”