Adam C. Overvig's research while affiliated with CUNY Graduate Center and other places

Publications (52)

Article
Full-text available
Photonic devices rarely provide both elaborate spatial control and sharp spectral control over an incoming wavefront. In optical metasurfaces, for example, the localized modes of individual meta-units govern the wavefront shape over a broad bandwidth, while nonlocal lattice modes extended over many unit cells support high quality-factor resonances....
Preprint
Full-text available
Metasurfaces have been rapidly advancing our command over the many degrees of freedom of light within compact, lightweight devices. However, so far, they have mostly been limited to manipulating light in free space. Grating couplers provide the opportunity of bridging far-field optical radiation and in-plane guided waves, and thus have become funda...
Article
Full-text available
Optical metasurfaces with high quality factors (Q-factors) of chiral resonances can boost substantially light-matter interaction for various applications of chiral response in ultrathin, active, and nonlinear metadevices. However, current approaches lack the flexibility to enhance and tune the chirality and Q-factor simultaneously. Here, we suggest...
Article
Metasurfaces are ushering in an era of multifunctional control over optical wavefronts realized with ultrathin planarized devices. Recent advances have been enabling unprecedented control over the frequency response of these surfaces, suggesting that the future of flat optics may tailor both spectral and spatial degrees of freedom in highly multisp...
Preprint
High quality (Q) factor optical resonators are indispensable for many photonic devices. While very large Q-factors can be obtained theoretically in guided mode settings, free-space implementations suffer from various limitations on the narrowest possible linewidth in real experiments. In these devices, the largest Q-factors are hindered by radiatio...
Preprint
Full-text available
Optical metasurfaces with high-Q chiral resonances can boost light-matter interaction for various applications of chiral response for ultrathin, active, and nonlinear metadevices. Usually, such metasurfaces require sophisticated depth-resolved nanofabrication to realize subwavelength stereo-nanostructures, posing overwhelming challenges, especially...
Article
Full-text available
Metasurfaces have been enabling the miniaturization and integration of complex optical functionalities within an ultrathin platform by engineering the scattering features of localized modes. However, these efforts have mostly been limited to the manipulation of externally produced coherent light, e.g., from a laser. In parallel, the past two decade...
Article
Quasi-bound states in the continuum (QBICs) are Fano resonant states with long optical lifetimes controlled by symmetry-breaking perturbations. While conventional Fano responses are limited to linear polarizations and do not support tailored phase control, here we introduce QBICs born of chiral perturbations that encode arbitrary elliptical polariz...
Article
Full-text available
Actively tunable and reconfigurable wavefront shaping by optical metasurfaces poses a significant technical challenge often requiring unconventional materials engineering and nanofabrication. Most wavefront-shaping metasurfaces can be considered “local” in that their operation depends on the responses of individual meta-units. In contrast, “nonloca...
Article
Full-text available
Strong field confinement, long-lifetime resonances, and slow-light effects suggest that metasurfaces are a promising tool for nonlinear optical applications. These nanostructured devices have been utilized for relatively high efficiency solid-state high-harmonic generation platforms, four-wave mixing, and Raman scattering experiments, among others....
Preprint
Full-text available
Photonic devices rarely provide both elaborate spatial control and sharp spectral control over an incoming wavefront. In optical metasurfaces, for example, the localized modes of individual meta-units govern the wavefront shape over a broad bandwidth, while nonlocal lattice modes extended over many meta-units support high quality-factor resonances....
Preprint
Strong field-confinement, long-lifetime resonances, and slow-light effects suggest that meta surfaces are a promising tool for nonlinear optical applications. These nanostructured devices have been utilized for relatively high efficiency solid-state high-harmonic generation platforms, four-wave mixing, and Raman scattering experiments, among others...
Preprint
Actively tunable and reconfigurable wavefront shaping by optical metasurfaces poses a significant technical challenge often requiring unconventional materials engineering and nanofabrication. Most wavefront-shaping metasurfaces can be considered 'local' in that their operation depends on the responses of individual meta-units. In contrast, 'nonloca...
Article
Photonic crystal slabs (PCSs) are a well-studied class of devices known to support optical Fano resonances for light normally incident to the slab, useful for narrow-band filters, modulators, and nonlinear photonic devices. In shallow-etched PCSs the linewidth of the resonances is easily controlled by tuning the etching depth. This design strength...
Article
Diffractive photonic devices manipulate light via local and nonlocal optical modes. Local devices, such as metasurfaces, can shape a wave front at multiple selected wavelengths, but inevitably modify light across the spectrum; nonlocal devices, such as grating filters, offer great frequency selectivity but limited spatial control. Here, we introduc...
Preprint
Quasi-bound states in the continuum (q-BICs) are resonant states of suitably tailored nanostructures with long optical lifetimes controlled by symmetry-breaking perturbations. While in planarized ultrathin devices the resulting Fano resonance is limited to linear polarizations, we show here that chiral perturbations extend q-BIC concepts to arbitra...
Preprint
Diffractive photonic devices manipulate light via local and nonlocal optical modes. Local devices, such as metasurfaces, can shape a wavefront at multiple selected wavelengths, but inevitably modify light across the spectrum; nonlocal devices, such as grating filters, offer great frequency selectivity but limited spatial control. Here, we introduce...
Conference Paper
We report experimental demonstrations of a phase-amplitude metasurface doublet capable of producing 2D artifact-free, full-color holographic images.
Conference Paper
We experimentally demonstrate dielectric metasurfaces that support spatially tailored dark modes (quasi-Bound States in the Continuum) and mold optical wavefronts only at narrowband Fano resonances, while leaving the rest of the spectrum unaffected.
Article
Adaptive control of broadband light is essential for diverse applications including building energy management and light modulation. Here, we present porous polymer coatings (PPCs), whose optical transmittance changes upon reversible wetting with common liquids, as a platform for optical management from solar to thermal wavelengths. In the solar wa...
Article
Full-text available
Metasurfaces are optically thin metamaterials that promise complete control of the wavefront of light but are primarily used to control only the phase of light. Here, we present an approach, simple in concept and in practice, that uses meta-atoms with a varying degree of form birefringence and rotation angles to create high-efficiency dielectric me...
Preprint
Photonic crystal slabs (PCSs) are a well-studied class of devices known to support optical Fano resonances for light normally incident to the slab, useful for narrowband filters, modulators, and nonlinear photonic devices. In shallow-etched PCSs the linewidth of the resonances is easily controlled by tuning the etching depth. This design strength c...
Preprint
Metasurfaces are optically thin metamaterials that promise complete control of the wavefront of light, but principally are used to control only the phase of light. Here, we present an approach, simple in concept and in practice, using meta-atoms with a varying degree of form birefringence and rotation angles to create high efficiency dielectric met...
Conference Paper
We experimentally demonstrated chromatic and monochromatic aberration correction in a meta-lens triplet system up to a wavelength range of ~300 nm in the near-infrared by utilizing dispersion engineering of meta-atoms.
Conference Paper
We investigate periodic symmetry breaking as a method of controlling Fano resonances in high contrast dielectric gratings with small device footprints and report experimental and computational demonstrations of free-space modulators based on these dimerized gratings.
Conference Paper
We design and fabricate a dielectric metasurface for enhancing harmonic generation from gases with mid-infrared pulses. We observe third-harmonic generation in Ar at pump intensities as low as 1.8 ×1012 W/cm2.
Article
Full-text available
Broadband high reflectance in nature is often the result of randomly, three-dimensionally structured materials. This study explores unique optical properties associated with one-dimensional nanostructures discovered in silk cocoon fibers of the comet moth, Argema mittrei. The fibers are populated with a high density of air voids randomly distribute...
Article
Full-text available
Small, high-performance imaging systems could be built using flat lenses made from specially arranged nanoscale pillars. Traditional lenses rely on the curvature and thickness of glass to focus light, but metalenses, which can be smaller, thinner, and more flexible, have surfaces comprised of thousands of nanoscale pillars whose geometries are care...
Article
Passive daytime radiative cooling (PDRC) involves spontaneously cooling a surface by reflecting sunlight and radiating heat to the cold outer space. Current PDRC designs are promising alternatives to electrical cooling, but are either inefficient or have limited applicability. We present a simple, inexpensive and scalable phase-inversion-based meth...
Article
Full-text available
Metamaterials have been designed to achieve a wide range of functionalities. Metamaterial absorbers are of particular interest for various applications such as infrared detectors, emissivity coatings, and photovoltaic cells. Various metamaterial platforms have been demonstrated to achieve perfect absorption and several attempts have been made to ex...
Article
Full-text available
Metasurfaces and planar photonic crystals are two classes of subwavelength diffractive optical devices offering novel functionalities. The former employ independently operating subwavelength “meta-units” as their building blocks, while the latter exploit the collective response of many periodic building blocks. High contrast gratings (HCGs) are an...
Conference Paper
We experimentally demonstrated chromatic aberration correction in converging and diverging metalenses up to wavelength range of ~450 nm in the near-infrared by utilizing dispersion engineering of meta-units.
Conference Paper
We report a high-efficiency dielectric metasurface with continuous and arbitrary control of both amplitude and phase of one or two colors simultaneously. We numerically and experimentally demonstrate 2D and 3D holograms using such metasurfaces.
Article
A simple, inexpensive, ecofriendly and scalable technique for fabricating highly efficient selective solar absorbers (SSAs) is reported by Nanfang Yu, Yuan Yang, and co-workers in article number 1702156. The technique yields SSAs with excellent wide-angle solar absorptance (≈96% at 0° and ≈79% at 70°), which is higher than, and low thermal emittanc...
Article
Full-text available
Full Text Available Here: http://arxiv.org/pdf/1809.05184 A galvanic-displacement-reaction-based, room-temperature "dip-and-dry" technique is demonstrated for fabricating selectively solar-absorbing plasmonic-nanoparticle-coated foils (PNFs). The technique, which allows for facile tuning of the PNFs' spectral reflectance to suit different radiativ...
Article
Full-text available
Transparent conductive oxides (TCOs) have emerged as alternative plasmonic materials in recent years to replace noble metals. The advantages of TCOs include CMOS compatibility, tunability of optical and structural properties, and reduced losses. In this work, we demonstrate how post-deposition annealing of Indium Tin Oxide (ITO) films in oxygen atm...
Article
Research on two-dimensional designer optical structures, or metasurfaces, has mainly focused on controlling the wavefronts of light propagating in free space. Here, we show that gradient metasurface structures consisting of phased arrays of plasmonic or dielectric nanoantennas can be used to control guided waves via strong optical scattering at sub...

Citations

... A lot of efforts have been made on local metasurfaces [21][22][23]. For nonlocal metasurface, recent studies have realized that tunable resonance frequency on nonlocal metasurface arising from thermo-optic effects [24]. In photonics crystal (PhC) slabs, there is a special collective mode named bound states in the continuum (BIC). ...
... Considerable progress has been achieved in engineering the thermal spectrum, radiation directionality, polarization and temporal response [167][168][169]. The emission spectrum of nanorod emitter shows narrow-band resonance peaks because the spectrum are strongly related to the LSPR properties ( Fig. 11d-f) [163,166]. ...
... When the symmetry is lifted, a scattering line emerges, whose linewidth can be carefully controlled through the degree of broken symmetry, which tailors the ratio of stored energy and an overall loss in the system, sustained by absorption, radiation, and polarization conversion. Given that radiation damping is carefully controlled by symmetry breaking, the resonance linewidth can be carefully tuned and controlled, yielding remarkable features of great interest for various linear and nonlinear applications [17][18][19][20][21][22][23] . ...
... When the symmetry is lifted, a scattering line emerges, whose linewidth can be carefully controlled through the degree of broken symmetry, which tailors the ratio of stored energy and an overall loss in the system, sustained by absorption, radiation, and polarization conversion. Given that radiation damping is carefully controlled by symmetry breaking, the resonance linewidth can be carefully tuned and controlled, yielding remarkable features of great interest for various linear and nonlinear applications [17][18][19][20][21][22][23] . ...
... Second, no fine tuning of the structure is necessary to adjust the BIC's location in wavevector space, since the BIC is guaranteed to exist at normal incidence. As such, symmetry-protected BICs in photonic crystal slabs and all-dielectric metasurfaces have been demonstrated to enable or enhance a wide variety of different applications, such as sensors [25][26][27], high power on-chip lasers [28,29], vortex lasers [30,31], harmonic generation [32][33][34][35][36][37], and increased control over transmission and reflection spectra [38][39][40][41][42]. ...
... Due to constraints in the ability to control an optical wavefront, metasurface holography is conventionally performed with a meta-atom library that controls only the phase 36 . Recent efforts have demonstrated meta-atom geometries allowing simultaneous amplitude and phase control and explored the benefits thereof for holography [37][38][39][40] . However, these efforts have been limited in efficiency or achieve results with unnecessary complexity. ...
... Potential applications of active metasurfaces[63][64][65][66][67][68][69][70][71][72][73][74][75][76][77]: green-yellow-gray colors indicate decreasing relevance of the metric to the target use case: very important-somewhat importantminimally relevant (refer to Supplementary Information for more details and discussions) Note that amplitude modulation can be implemented with phase modulation via interference effects although the reverse is not true: phase modulation cannot be realized by amplitude modulation alone. b Taking the Stratospheric Aerosol and Gas Experiment as an example, the science observation events are a maximum length of 6 minutes, and the filter will be switched 5 times per second during the event. ...
... Arrows indicate light propagation directions at the three colors single-function metasurface based on p2 meta-units operating at the green wavelength and a dual-function metasurface based on p1 meta-units operating at the red and blue wavelengths (Fig. 6b). Both metasurfaces are composed of rectangular apertures etched into a thin film of TiO 2 covered with an antireflection layer of SiO 2 and are compatible with previously demonstrated fabrication methods 41,42 . Figure 6c highlights the broadband hightransmission of real-world light and the narrowband reflection at the three chosen wavelengths in the visible for the doublet, calculated by finite-difference timedomain simulations and an incoherent transfer matrix method 43 . ...
... In our previous works, we have demonstrated theoretically [24,25] and experimentally [26] a generalization of nonlocal metasurfaces capable of shaping an optical wavefront by spatially varying the polarization properties of q-BICs. In particular, by using a geometric phase associated with the linear [25] or circular [27] dichroism of Fano resonances supported by suitably perturbed photonic crystal slabs, nonlocal metasurfaces have been demonstrated that shape light only across the narrow spectral bandwidth of the resonance. ...
... In this work, we design and experimentally realize nonlocal metasurfaces that shape optical wavefronts exclusively at selected wavelengths, leaving the optical wavefront impinging at other wavelengths unchanged ( Fig. 1a right panel). Our theoretical work has developed the framework of nonlocal metasurfaces that shape the wavefront only on resonance 15,16 . This is achievable through a scalable rational design scheme previously only available to local metasurfaces, in which the configuration of scatterers across the surface is determined by reference to a precomputed library of meta-units. ...