Low angular separation point sources are vital in astronomy, such as the search for exoplanets. Traditional imaging is time-consuming, but we propose quantum-accelerated imaging (QAI) to reduce measurement time using an information-theoretic approach. QAI maximizes Fisher information per detected photon by adaptively learning optimal measurements from data. Using linear-projection instruments and single-photon detectors, we estimate the position, brightness, and number of unknown stars 10-100 times faster than direct imaging. QAI is scalable and applicable in high-speed imaging, fluorescence microscopy, and optical read-out of qubits beyond astronomy.
The concept of photonic frequency (ω) - momentum (𝑞) dispersion has been extensively studied in artificial dielectric structures such as photonic crystals and metamaterials. However, the ω−𝑞 dispersion of electrodynamic waves hosted in natural materials at the atomistic level is far less explored. Here, we develop an atomistic nonlocal electrodynamic theory of matter by combining the Maxwell Hamiltonian theory of matter with a quantum theory of atomistic polarization. We apply this theory to silicon and discover the existence of atomistic electrodynamic waves. Atomistic electrodynamic waves have sub-nano-meter effective wavelengths in the picoelectrodynamics regime. Further, we show that the atomistic optical conductivity in silicon is highly anisotropic along different momentum directions due to atomistic electronic correlations. Our findings demonstrate that the natural media host variety of yet to be discovered electromagnetic phases of matter and provide a pathway towards the discovery of rich atomic scale light-matter interaction phenomena.
The fluctuational electrodynamic investigation of thermal radiation from non-equilibrium or non-isothermal bodies remains largely unexplored because of severe numerical difficulties. Here, we employ fast calculations based on modal expansion to accelerate research at this frontier. We employ our formalism on a long silica wire held under temperature gradient within its cross section. We discover that the far-field thermal emission carries a nonzero spin which is constant in direction and sign, and interestingly, is transverse to the direction of the power flow. We establish the origin of this transverse spin as arising from the nonequilibrium intermixing of the modes of the wire, and not from any previously studied or intuitively expected origins such as chiral or nonisotropic materials and geometries, magnetic materials or fields, and mechanical rotations. This finding emitted heat radiation can prove useful for advancing the noninvasive thermal metrology or infrared imaging technique
We present a novel spectro-polarimetric long-wave infrared (LWIR) thermal imaging system based on spinning metasurfaces. By utilizing the intrinsic dispersion in high-contrast anisotropic metasurfaces, we are able to generate tunable transmission spectra and achieve high spectral resolution. Our system enables simultaneous spectrum- and polarization-resolved thermal imaging, allowing for the extraction of hidden information in thermal radiation. Our low size, weight, and power (SWaP) system is a promising next-generation solution for high-quality thermal imagery data.
Over the past three decades, graphene has become the prototypical platform for discovering topological phases of matter. Both the Chern C∈Z and quantum spin Hall υ∈Z2 insulators were first predicted in graphene, which led to a veritable explosion of research in topological materials. We introduce a new topological classification of two-dimensional matter – the optical N-phases N∈Z. This topological quantum number is connected to polarization transport and captured solely by the spatiotemporal dispersion of the susceptibility tensor χ. We verify N ≠ 0 in graphene with the underlying physical mechanism being repulsive Hall viscosity. An experimental probe, evanescent magneto-optic Kerr effect (e-MOKE) spectroscopy, is proposed to explore the N-invariant. We also develop topological circulators by exploiting gapless edge plasmons that are immune to back-scattering and navigate sharp defects with impunity. Our work indicates that graphene with repulsive Hall viscosity is the first candidate material for a topological electromagnetic phase of matter.
Nitrogen-vacancy (NV) centers in diamond have emerged as promising room temperature quantum sensors for probing condensed matter phenomena ranging from spin liquids, 2D magnetic materials, and magnons to hydrodynamic flow of current. Here, we propose and demonstrate that the NV center in diamond can be used as a quantum sensor for detecting the photonic spin density. We demonstrate this probe both for the case of a single NV center and an ensemble of NV centers. The spinning field of light induces an effective static magnetic field in the spin qubit probe. We perform room-temperature sensing using Bloch sphere operations driven by a microwave field (XY8 protocol) to detect the photonic spin density induced effective static magnetic field.
KEYWORDS: Near field optics, Nanophotonics, Sensors, Polarization, Photons, Diamond, Temperature metrology, Photon polarization, Optical testing, Near field
Photonic spin density (PSD) in the near-field gives rise to exotic phenomena such as photonic skyrmions, optical spin-momentum locking and unidirectional topological edge waves. Experimental investigation of these phenomena requires a nanoscale probe that directly interacts with PSD. Here, we propose and demonstrate that the nitrogen-vacancy (NV) center in diamond can be used as a quantum sensor for detecting the spinning nature of photons. This room temperature magnetometer can measure the local polarization of light in ultra-subwavelength volumes through photon-spin-induced virtual transitions. The direct detection of light's spin density at the nanoscale using NV centers in diamond opens a new frontier for studying exotic phases of photons as well as future on-chip applications.
We introduce a first-order quantum-phase-transition model, which exhibits giant sensitivity χ∝N2 at the critical point. Exploiting this effect, we propose a quantum critical detector (QCD) to amplify weak input signals. The time-dynamic QCD functions by triggering a first-order dynamical quantum phase transition in a system of spins with long-range interactions coupled to a bosonic mode. We numerically demonstrate features of the dynamical quantum phase transition, which leads to a time-dependent quantum gain. We also show the linear scaling with the spin number N in both the quantum gain and the corresponding signal-to-quantum noise ratio of this QCD. Our QCD can be a resource for metrology, weak signal amplification, and single photon detection.
In this paper, we elucidate the fundamental difference between the magnetic monopoles appearing in Maxwell’s equations and the Dirac equation. Our work shows that a magnetic monopole appears for both photons and massless fermions in the reciprocal energy-momentum space - even for vacuum. Using a Dirac-Maxwell correspondence, we identify the bosonic and fermionic nature of magnetic monopole charge, which is inherently present in the relativistic theories of both particles. While the results in vacuum are expected, we apply this topological theory to 2D photonic (bosonic) materials, in contrast to conventional electronic (fermionic) materials. The specific 2D photonic materials considered in this paper are gyroelectric which possess antisymmetric components of the conductivity tensor. We exploit the Dirac-Maxwell correspondence to show how dispersive gyroelectric media can support topologically massive particles, which are interpreted as photonic skyrmions. However, the differences in spin between bosons and fermions alter the behavior of these bulk skyrmions as well as their corresponding Chern numbers. We then analyze the unique topological edge states associated with nontrivial spin-1 and spin-½ skyrmions, which exhibit opposing helical quantization. This clearly shows how the integer and half-integer nature of monopoles is ultimately tied to the differing bosonic and fermionic spin symmetries. Our work sheds light on the recently proposed quantum gyroelectric phase of matter [32] which supports unidirectional transverse electro-magnetic (TEM) edge states with open boundary conditions (vanishing fields at the edge) - unlike any known phase of matter till date.
Vacuum consists of a bath of balanced and symmetric positive and negative frequency fluctuations. Media in relative motion or accelerated observers can break this symmetry and preferentially amplify negative frequency modes as in Quantum Cherenkov radiation and Unruh radiation. Here, we show the existence of a universal negative frequency-momentum mirror symmetry in the relativistic Lorentzian transformation for electromagnetic waves. We show the connection of our discovered symmetry to parity-time (PT) symmetry in moving media and the resulting spectral singularity in vacuum fluctuation related effects. We prove that this spectral singularity can occur in the case of two metallic plates in relative motion interacting through positive and negative frequency plasmonic fluctuations (negative frequency resonance). Our work paves the way for understanding the role of PT-symmetric spectral singularities in amplifying fluctuations and motivates the search for PT-symmetry in novel photonic systems.
[1] arXiv:1612.02050 [physics.optics]
We show the existence of an inherent property of evanescent electromagnetic waves: spin-momentum locking, where the direction of momentum fundamentally locks the polarization of the wave. We trace the ultimate origin of this phenomenon to complex dispersion and causality requirements on evanescent waves. We demonstrate that every case of evanescent waves in total internal reflection, surface states and optical fibers/waveguides possesses this intrinsic spin-momentum locking. We also introduce a universal right-handed triplet consisting of momentum, decay and spin for evanescent waves. We derive the Stokes parameters for evanescent waves which reveal an intriguing result - every fast decaying evanescent wave is inherently circularly polarized with its handedness tied to the direction of propagation. We also show the existence of a fundamental angle associated with total internal reflection (TIR) such that propagating waves locally inherit perfect circular polarized characteristics from the evanescent wave. This circular TIR condition occurs if and only if the ratio of permittivities of the two dielectric media exceeds the golden ratio. Our work leads to a unified understanding of this spin-momentum locking in various nanophotonic experiments and sheds light on the electromagnetic analogy with the quantum spin hall state for electrons.
Here, we surpass the diffraction limit of light by a new class of all-dielectric artificial materials that are lossless. This overcomes one of the fundamental challenges of light confinement in metamaterials and plasmonics: metallic loss. Our approach relies on controlling the optical momentum of evanescent waves as opposed to conventional photonic devices which manipulate propagating waves. This leads to a counterintuitive confinement strategy for electromagnetic waves across the entire spectrum. We introduce two distinct photonic design principles that can ideally lead to sub-diffraction light confinement without metal. They are i) relaxed total internal reflection and ii) photonic skin-depth engineering. We present initial experimental results on a CMOS compatible platform that prove the enhanced confinement of our all-dielectric metamaterial design.
Improvement in high-temperature stable spectrally selective absorbers and emitters is integral for the further development of thermophotovoltaic (TPV), lighting and solar thermal applications. However, the high operational temperatures (T>1000oC) required for efficient energy conversion, along with application specific criteria such as the operational range of low bandgap semiconductors, greatly restrict what can be accomplished with natural materials.
Motivated by this challenge, we demonstrate the first example of high temperature thermal radiation engineering with metamaterials. By employing the naturally selective thermal excitation of radiative modes that occurs near topological transitions, we show that thermally stable highly selective emissivity features are achieved for temperatures up to 1000°C with low angular dependence in a sub-micron thick refractory tungsten/hafnium dioxide epsilon-near-zero (ENZ) metamaterial. We also investigate the main mechanisms of thermal degradation of the fabricated refractory metamaterial both in terms of optical performance and structural stability using spectral analysis and energy-dispersive X-ray spectroscopy (EDS) techniques. Importantly, we observe chemical stability of the constituent materials for temperatures up to 1000°C and structural stability beyond 1100°C.
The scalable fabrication, requiring magnetron sputtering, and thermally robust optical properties of this metamaterial approach are ideally suited to high temperature emitter applications such as lighting or TPV. Our findings provide a first concrete proof of radiative engineering with high temperature topological transition in ENZ metamaterials, and establish a clear path for implementation in TPV energy harvesting applications.
We use Rytov's fluctuational electrodynamics to show that Van Der Waals interactions are fundamentally modified by metamaterials. We verify the conditions under which the effect is strongest and also show initial experimental results to prove the same. En route to developing the van der waals theory in metamaterials we have also adopted a unique approach to quantization in lossy dispersive media.
We develop the ray optic Hamiltonian for a cylindrically anisotropic medium such as the hyperlens using the
semiclassical approximation, which reveals an interesting spiralling behaviour of ray trajectories and also gives
an alternative explanation to the subdiffraction far field imaging behaviour of the device. The Hamiltonian can
be further used to derive the material parameters needed for non magnetic cloaking. Numerical simulations of
gaussian beam scattering from these devices confirm the respective semiclassical results.
KEYWORDS: Dielectrics, Wave propagation, Diffraction, Anisotropy, Metamaterials, Optical imaging, Near field optics, Image resolution, Near field scanning optical microscopy, Dispersion
We propose an approach to far-field optical imaging beyond the diffraction limit. The proposed system allows
image magnification, is robust with respect to material losses and can be fabricated by adapting existing
metamaterial technologies in a cylindrical geometry.
KEYWORDS: Near field optics, Dielectrics, Metamaterials, Refractive index, Diffraction, Dispersion, Optical imaging, Anisotropy, Near field scanning optical microscopy, Refraction
We propose an approach to far field optical imaging below the diffraction limit, based on dielectric metamaterials with strong anisotropy. As opposed to the "superlens" that relies on negative index materials, our method allows image magnification and is robust with respect to material losses.
Access to the requested content is limited to institutions that have purchased or subscribe to SPIE eBooks.
You are receiving this notice because your organization may not have SPIE eBooks access.*
*Shibboleth/Open Athens users─please
sign in
to access your institution's subscriptions.
To obtain this item, you may purchase the complete book in print or electronic format on
SPIE.org.
INSTITUTIONAL Select your institution to access the SPIE Digital Library.
PERSONAL Sign in with your SPIE account to access your personal subscriptions or to use specific features such as save to my library, sign up for alerts, save searches, etc.