We consider various examples to show that metamaterials present a unified platform to engineer all three states of light: coherent states as in a laser, thermal states and quantum states (eg: single photons).
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.
Superconducting nanowire single-photon detectors have emerged as a promising technology for quantum metrology from the mid-infrared to ultraviolet frequencies. Despite recent experimental successes, a predictive model to describe the detection event in these detectors is needed to optimize the detection metrics. Here, we propose a probabilistic criterion for single-photon detection based on single-vortex (flux quanta) crossing the width of the nanowire. Our model makes a connection between the dark counts and photon counts near the detection threshold. The finite-difference calculations demonstrate that a change in the bias current distribution as a result of the photon absorption significantly increases the probability of single-vortex crossing even if the vortex potential barrier has not vanished completely. We estimate the instrument response function and show that the timing uncertainty of this vortex tunneling process corresponds to a fundamental limit in timing jitter of the click event. We demonstrate a trade-space between this intrinsic (quantum) timing jitter, quantum efficiency, and dark count rate in TaN, WSi, and NbN superconducting nanowires at different experimental conditions. Our detection model can also explain the experimental observation of exponential decrease in the quantum efficiency of SNSPDs at lower energies. This leads to a pulse-width dependency in the quantum efficiency, and it can be further used as an experimental test to compare across different detection models.
All optical switches offer advanced control over the properties of light at ultrafast timescales using optical pulses as both the signal and the control. Limited only by material response times, these switches can operate at terahertz speeds, essential for technology-driven applications such as all-optical signal processing and ultrafast imaging, as well as for fundamental studies such as frequency translation and novel optical media concepts such as photonic time crystals. In conventional systems, the switching time is determined by the relaxation response of a single active material, which is challenging to adjust dynamically. This work demonstrates that the zero-to-zero response time of an all-optical switch can instead be varied through the combination of so-called fast and slow materials in a single device. When probed in the epsilon-near-zero operational regime of a material with a slow response time, namely, plasmonic titanium nitride, the switch exhibits a relatively slow, nanosecond response time. The response time then decreases reaching the picosecond time scale in the ENZ regime of the faster material, namely, aluminum-doped zinc oxide. Overall, the response time of the switch is shown to vary by two orders of magnitude in a single device and can be selectively controlled through the interaction of the probe signal with the constituent materials. The ability to adjust the switching speed by controlling the light-matter interaction in a multi-material structure provides an additional degree of freedom in all-optical switch design. Moreover, the proposed approach utilizes slower materials that are very robust and allow to enhance the field intensities while faster materials ensure an ultrafast dynamic response. The proposed control of the switching time could lead to new functionalities within key applications in multiband transmission, optical computing, and nonlinear optics.
Tailoring optical and radiative properties has attracted significant attention recently due to its importance in advanced energy systems, nanophotonics, electro-optics, and nanomanufacturing. Metamaterials with micro- and nanostructures exhibit exotic radiative properties with tunability across the spectrum, direction, and polarization. Structures made from anisotropic or nanostructured materials have shown polarization-selective absorption bands in the mid-infrared. Characterizing the optical and radiative properties of such materials is crucial for both fundamental research and the development of practical applications. Mueller matrix ellipsometry offers a nondestructive and noninvasive technique for characterizing radiative properties. Although such ellipsometers have long been used to measure optical properties, their operational bandwidth is usually limited to the visible to near-infrared range, leaving the mid-infrared largely unexplored. In this work, a broadband mid-infrared ellipsometer, operating from 2 to 15 μm, is designed and constructed to measure 12 elements of the Mueller matrix. The results may be used to determine the full Mueller matrix under specific conditions. The performance of the ellipsometer is evaluated using nanostructured materials, including a 1D grating and a chiral F-shaped metasurface. The measurement results compared well to those obtained from rigorous-coupled-wave analysis and finite-difference time-domain simulations, suggesting that this setup offers a useful tool in optical property retrieval and the assessment of nanostructured materials.
We propose a metamaterial device capable of highly directional thermal radiation using the Wolf effect. Our structure provides high emissivity in a narrow band and is tunable over a broad range of frequencies.
Silicon is widely used as the material of choice for semiconductor and insulator applications in nanoelectronics, micro-electro-mechanical systems, solar cells, and on-chip photonics. In stark contrast, in this paper, we explore silicon’s metallic properties and show that it can support propagating surface plasmons, collective charge oscillations, in the extreme ultraviolet (EUV) energy regime not possible with other plasmonic materials such as aluminum, silver, or gold. This is fundamentally different from conventional approaches, where doping semiconductors is considered necessary to observe plasmonic behavior. We experimentally map the photonic band structure of EUV surface and bulk plasmons in silicon using momentum-resolved electron energy loss spectroscopy. Our experimental observations are validated by macroscopic electrodynamic electron energy loss theory simulations as well as quantum density functional theory calculations. As an example of exploiting these EUV plasmons for applications, we propose a tunable and broadband thresholdless Cherenkov radiation source in the EUV using silicon plasmonic metamaterials. Our work can pave the way for the field of EUV plasmonics.
In this paper, we develop an advanced volume integral equation solver to simulate metallic quantum gate structures. The solver accurately predicts evanescent wave Johnson noise (EWJN) induced decay rates, which is successfully applied to optimize the control pulse for mitigating the influence of EWJN.
In this paper, we develop an advanced volume integral equation solver to simulate metallic quantum gate structures. The solver accurately predicts evanescent wave Johnson noise (EWJN) induced decay rates, which is successfully applied to optimize the control pulse for mitigating the influence of EWJN.
We derive a unified quantum theory of coherent and incoherent energy transfer between two atoms (donor and acceptor) valid in arbitrary Markovian nanophotonic environments. Our theory predicts a fundamental bound ηmax =γaγd+γa for energy transfer efficiency arising from the spontaneous emission rates γd and γa of the donor and acceptor. We propose the control of the acceptor spontaneous emission rate as a new design principle for enhancing energy transfer efficiency. We predict an experiment using mirrors to enhance the efficiency bound by exploiting the dipole orientations of the donor and acceptor. Of fundamental interest, we show that while quantum coherence implies the ultimate efficiency bound has been reached, reaching the ultimate efficiency does not require quantum coherence. Our work paves the way towards nanophotonic analogues of efficiency-enhancing environments known in quantum biological systems.
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