Hasil untuk "Optics. Light"

W. D. Wright

M. Quinten, A. Leitner, J. Krenn et al.

A. Yariv

F. Leo, S. Coen, P. Kockaert et al.

P. Forn-D'iaz, J. García-Ripoll, B. Peropadre et al.

A superconducting artificial atom coupled to a 1D waveguide tests the limits of light–matter interaction in an unexplored coupling regime, which may enable new perspectives for quantum technologies. The study of light–matter interaction has led to important advances in quantum optics and enabled numerous technologies. Over recent decades, progress has been made in increasing the strength of this interaction at the single-photon level. More recently, a major achievement has been the demonstration of the so-called strong coupling regime1,2, a key advancement enabling progress in quantum information science. Here, we demonstrate light–matter interaction over an order of magnitude stronger than previously reported, reaching the nonperturbative regime of ultrastrong coupling (USC). We achieve this using a superconducting artificial atom tunably coupled to the electromagnetic continuum of a one-dimensional waveguide. For the largest coupling, the spontaneous emission rate of the atom exceeds its transition frequency. In this USC regime, the description of atom and light as distinct entities breaks down, and a new description in terms of hybrid states is required3,4. Beyond light–matter interaction itself, the tunability of our system makes it a promising tool to study a number of important physical systems, such as the well-known spin-boson5 and Kondo models6.

D. Basov, A. Asenjo-Garcia, P. Schuck et al.

Abstract In this brief review, we summarize and elaborate on some of the nomenclature of polaritonic phenomena and systems as they appear in the literature on quantum materials and quantum optics. Our summary includes at least 70 different types of polaritonic light–matter dressing effects. This summary also unravels a broad panorama of the physics and applications of polaritons. A constantly updated version of this review is available at https://infrared.cni.columbia.edu.

N. Kinsey, C. DeVault, A. Boltasseva et al.

K. Mehta, Chi Zhang, M. Malinowski et al.

Practical and useful quantum information processing requires substantial improvements with respect to current systems, both in the error rates of basic operations and in scale. The fundamental qualities of individual trapped-ion1 qubits are promising for long-term systems2, but the optics involved in their precise control are a barrier to scaling3. Planar-fabricated optics integrated within ion-trap devices can make such systems simultaneously more robust and parallelizable, as suggested by previous work with single ions4. Here we use scalable optics co-fabricated with a surface-electrode ion trap to achieve high-fidelity multi-ion quantum logic gates, which are often the limiting elements in building up the precise, large-scale entanglement that is essential to quantum computation. Light is efficiently delivered to a trap chip in a cryogenic environment via direct fibre coupling on multiple channels, eliminating the need for beam alignment into vacuum systems and cryostats and lending robustness to vibrations and beam-pointing drifts. This allows us to perform ground-state laser cooling of ion motion and to implement gates generating two-ion entangled states with fidelities greater than 99.3(2) per cent. This work demonstrates hardware that reduces noise and drifts in sensitive quantum logic, and simultaneously offers a route to practical parallelization for high-fidelity quantum processors5. Similar devices may also find applications in atom- and ion-based quantum sensing and timekeeping6. Scalable optics co-fabricated with a cryogenic surface-electrode ion trap are used to drive high-fidelity multi-ion quantum logic gates, demonstrating a route to simultaneously scale and reduce errors in quantum processors.

Junxi Zhang, Lide Zhang, W. Xu

Mohammadsadegh Faraji-Dana, E. Arbabi, A. Arbabi et al.

An optical design space that can highly benefit from the recent developments in metasurfaces is the folded optics architecture where light is confined between reflective surfaces, and the wavefront is controlled at the reflective interfaces. In this manuscript, we introduce the concept of folded metasurface optics by demonstrating a compact spectrometer made from a 1-mm-thick glass slab with a volume of 7 cubic millimeters. The spectrometer has a resolution of ~1.2 nm, resolving more than 80 spectral points from 760 to 860 nm. The device is composed of three reflective dielectric metasurfaces, all fabricated in a single lithographic step on one side of a substrate, which simultaneously acts as the propagation space for light. The folded metasystem design can be applied to many optical systems, such as optical signal processors, interferometers, hyperspectral imagers, and computational optical systems, significantly reducing their sizes and increasing their mechanical robustness and potential for integration. Here, the authors introduce the folded metasurface optics architecture by demonstrating a compact high-resolution optical spectrometer made from a 1-mm-thick glass slab. The spectrometer has a resolution of 1.2 nm, resolving more than 80 spectral points in a 100-nm bandwidth centered at 810 nm.

Xinghui Yin, T. Steinle, Lingling Huang et al.

Compact nanophotonic elements exhibiting adaptable properties are essential components for the miniaturization of powerful optical technologies such as adaptive optics and spatial light modulators. While the larger counterparts typically rely on mechanical actuation, this can be undesirable in some cases on a microscopic scale due to inherent space restrictions. Here, we present a novel design concept for highly integrated active optical components that employs a combination of resonant plasmonic metasurfaces and the phase-change material Ge3Sb2Te6. In particular, we demonstrate beam switching and bifocal lensing, thus, paving the way for a plethora of active optical elements employing plasmonic metasurfaces, which follow the same design principles. Plasmonic metasurfaces employing a phase-change material have yielded highly compact devices for switching and focusing light beams. Such devices are promising for realizing nanophotonic components for applications in scanning, imaging and holography. Xinghui Yin at the University of Stuttgart, Germany, and co-workers fabricated gold patterned nanostructures on a layer of the phase-change material germanium−antimony−tellurium (GeSbTe; GST). Since the amorphous and crystalline phases of the GST layer have very different optical dielectric constants, thermally triggering a phase change in the layer allowed a 3.1 μm wavelength light beam to be steered in different directions. A different design of the gold nanopattern realized a cylindrical bifocal lens that had different focal lengths for the amorphous and crystalline GST phases. This demonstration opens the way for a wide range of active optical elements based on plasmonic metasurfaces.

Pierre-Élie Larré, Claire Michel, Nicolas Cherroret

We theoretically study the critical speed for superfluid flow of a two-dimensional (2D) binary superfluid of light past a polarization-sensitive optical obstacle. This speed corresponds to the maximum mean flow velocity below which dissipation is absent. In the weak-obstacle regime, linear-response theory shows that the critical speed is set by Landau's criterion applied to the density and spin Bogoliubov modes, whose relative ordering can be inverted due to saturation of the optical nonlinearity. For obstacles of arbitrary strength and large spatial extent, we determine the critical speed from the conditions for strong ellipticity of the stationary hydrodynamic equations within the hydraulic and incompressible approximations. Numerical simulations in this regime reveal that the breakdown of superfluidity is initiated by the nucleation of vortex-antivortex pairs for an impenetrable obstacle, and of Jones-Roberts soliton-type structures for a penetrable obstacle. Beyond superfluids of light, our results provide a general framework for the critical speed of 2D binary nonlinear Schrödinger superflows, including Bose-Bose quantum mixtures.

Deepika Gill, Sam Shallcross, Wenhan Chen et al.

Non-equilibrium quantum matter generated by ultrafast laser light opens new pathways in fundamental condensed matter physics, as well as offering rich control possibilities in "tailoring matter by light". Here we explore the coupling between free carriers and excitons mediated by femtosecond scale laser pulses. Employing monolayer WSe$_2$ and an {\it ab-initio} treatment of pump-probe spectroscopy we find that, counter-intuitively, laser light resonant with the exciton can generate massive enhancement of the early time free carrier population. This exhibits complex dynamical correlation to the excitons, with an oscillatory coupling between free carrier population and exciton peak height that persists. Our results both unveil "femto-excitons" as possessing a rich femtosecond dynamics as well as, we argue, allowing tailoring of early time light-matter interaction via laser pulse design to control simultaneously excitonic and free carrier physics at ultrafast times.

Vladimir R. Tuz, Vyacheslav V. Khardikov, Izzatjon Allayarov et al.

The development of modern optical communication systems requires specific waveguides, given that the widely used fiber‐optic components are poorly integrated with planar technologies. For planarization in the millimeter‐wave and subterahertz bands, so‐called gap waveguides are proposed, offering low‐loss performance and cost‐efficient manufacturing. Hence, the utilization of this technology in the optical range is very promising. Herein, a strategy for designing gap waveguides made of two metasurfaces composed of dielectric disk‐shaped resonators operated in hybrid HE (magnetic dipole) and EH (electric dipole) modes is proposed. The coupled dipole model is applied to the complex multiple‐scattering problem by substituting each resonator as an electric and magnetic dipole, providing equations for the efficient calculation of metasurface reflection and transmission properties. It is demonstrated that with the correct choice of metasurface geometry providing their resonant reflection conditions, a waveguide channel can be implemented between a pair of metasurfaces, which allows propagation of the transverse electric and transverse magnetic waves similar to those of a parallel plate waveguide with perfectly conducting either electric or magnetic walls. This approach may be seen as a novel metasurface‐based waveguide structure that uses flexibly mediated boundary conditions to control electromagnetic wave propagation.

Evgenii Menshikov, Paolo Franceschini, Kristina Frizyuk et al.

Shaping the structure of light with flat optical devices has driven significant advancements in our fundamental understanding of light and light-matter interactions, and enabled a broad range of applications, from image processing and microscopy to optical communication, quantum information processing, and the manipulation of microparticles. Yet, pushing the boundaries of structured light beyond the linear optical regime remains an open challenge. Nonlinear optical interactions, such as wave mixing in nonlinear flat optics, offer a powerful platform to unlock new degrees of freedom and functionalities for generating and detecting structured light. In this study, we experimentally demonstrate the non-trivial structuring of third-harmonic light enabled by the addition of total angular momentum projection in a nonlinear, isotropic flat optics element -- a single thin film of amorphous silicon. We identify the total angular momentum projection and helicity as the most critical properties for analyzing the experimental results. The theoretical model we propose, supported by numerical simulations, offers quantitative predictions for light structuring through nonlinear wave mixing under various pumping conditions, including vectorial and non-paraxial pump light. Notably, we reveal that the shape of third-harmonic light is highly sensitive to the polarization state of the pump. Our findings demonstrate that harnessing the addition of total angular momentum projection in nonlinear wave mixing can be a powerful strategy for generating and detecting precisely controlled structured light.

SangMyeong Lee, Hee Jung Kim, Young Ju Kim et al.

Owing to their excellent optoelectronic properties, halide perovskites (HPs) have garnered significant attention in the field of optoelectronics. However, conventional HPs‐based optoelectronic devices primarily are fabricated using solution‐based processes, implying that extremely time‐consuming needs to individually synthesize their composition‐dependent optoelectronic properties. This study demonstrates the feasibility of combining first‐principles simulations with combinatorial synthesis, comparing the effects of HP properties on optoelectronic devices using this combined approach. The first‐principles simulations confirm that increasing the ratio of small halide ions increased the band gap by k·p perturbation theory and harmonic oscillator models. By fabricating HP thin films with compositional gradients using combinatorial synthesis, it is confirmed that an increase in band gap corresponds to a decrease in static relative permittivity. Furthermore, HP‐based optoelectronic devices are fabricated to measure their photoelectric conversion efficiency and responsivity based on the simulated and measured relative permittivity, including time‐resolved photoluminescence. The findings demonstrate the influence of the relative permittivity on device performance, elucidating the relationship between band structure and relative permittivity. Therefore, in this study, the potential of combining first‐principles simulations with combinatorial synthesis is confirmed by comparing the relative permittivity characteristics of optoelectronics developed using this combined approach.

Guoshuai Zhu, Jianyun Xiong, Xing Li et al.

Abstract Neural stimulation and modulation at high spatial resolution are crucial for mediating neuronal signaling and plasticity, aiding in a better understanding of neuronal dysfunction and neurodegenerative diseases. However, developing a biocompatible and precisely controllable technique for accurate and effective stimulation and modulation of neurons at the subcellular level is highly challenging. Here, we report an optomechanical method for neural stimulation and modulation with subcellular precision using optically controlled bio-darts. The bio-dart is obtained from the tip of sunflower pollen grain and can generate transient pressure on the cell membrane with submicrometer spatial resolution when propelled by optical scattering force controlled with an optical fiber probe, which results in precision neural stimulation via precisely activation of membrane mechanosensitive ion channel. Importantly, controllable modulation of a single neuronal cell, even down to subcellular neuronal structures such as dendrites, axons, and soma, can be achieved. This bio-dart can also serve as a drug delivery tool for multifunctional neural stimulation and modulation. Remarkably, our optomechanical bio-darts can also be used for in vivo neural stimulation in larval zebrafish. This strategy provides a novel approach for neural stimulation and modulation with sub-cellular precision, paving the way for high-precision neuronal plasticity and neuromodulation.

Mahdi Rahmanpour, Alireza Erfanian, Ahmad Afifi et al.

Single photon avalanche diode (SPAD) is used in quantum detectors. Quantum detectors are widely used in quantum communication. The quality of these detectors strongly affects the optimal performance of the system. The quality of single photon detectors depends on various parameters, which are usually presented in the SPAD specification. If these detectors are made by the manufacturer or evaluated by the user, there is a need for a method to determine and check its main parameters. In this paper, a simple test setup for extracting some of important parameters has been designed and introduced, which can be used practically. These parameters include Dark Count Rate (DCR), Photon Detection Efficiency (PDE), AfterPulse Probability (APP) and Dead time. In the presented design, an FPGA chip is used to measure the parameters. FPGA is responsible for the simultaneous control of the single photon source and the detector. The presented methods specify how to extract the desired parameters. The characterization methods and detailed formulas presented in this paper calculate SPAD parameters.

Alireza Lanjani, Benjamin McEwen, Vincent Meyers et al.

Quantum well infrared photodetectors (QWIPs) have been demonstrated to be a suitable candidate for IR detection applications. These detectors attracted increasing interest due to their design flexibility and broad spectral absorption from short wave (SWIR) to long wave infrared (LWIR) and high uniformity. In this paper, we demonstrate device design, growth, and characterization of a <italic>p</italic>-type Al_xGa_1-xN&#x002F;GaN quantum well infrared photodetector (QWIP) for near IR absorption with 1.55 &#x03BC;m peak grown by metal organic chemical vapor deposition (MOCVD). Utilizing a <italic>p</italic>-QWIP allows for normal incidence light absorption due to the strong band mixing between heavy and light holes at <italic>k</italic> &#x2260; 0 which eliminates the need for light couplers such as grating and facilitates the fabrication of large focal plane arrays (FPAs). We developed MOCVD growth conditions to achieve nm-thick and smooth interfaces in QWIP. Sample characterizations including atomic force microscopy (AFM) show uniform surface morphology with RMS roughness &#x223C;0.5 nm. Scanning transmission electron microscopy (STEM) was used to characterize layer thicknesses and interface roughness. We demonstrate energy band diagram simulation of an Al_xGa_1-xN&#x002F;GaN <italic>p</italic>-QWIP by considering polarization chargers to determine the accurate band offset and adjust the absorption wavelength (ISBT energies). Our results show the feasibility of MOCVD-grown <italic>p</italic>-type Al_xGa_1-xN&#x002F;GaN QWIP for IR absorption and open a pathway for further research and growth development on III-Nitride <italic>p</italic>-QWIPs, allowing growth and fabrication of large focal plane arrays.

Mukesh Kumar, Azeemuddin Syed, Arpit Khandelwal et al.

In this article, an incoherent beam combination of higher-order Gaussian beams through atmospheric turbulence is studied. An analytical expression of the combined intensity and spot size of higher-order Gaussian beams such as Hermite Gaussian (HG), Laguerre Gaussian (LG), and Bessel Gaussian (BG) are derived. The performance of these higher-order Gaussian beams is analyzed in various modes including the effect of beam wander, jitter, bore-sight error, Strehl ratio, and Visibility. A series of analytical simulations shows the intensity variation of 19 higher-order combined beams. Spot size, peak, and average intensity comparisons are made between various modes of higher-order Gaussian beam combinations. It is seen that the spot size of the combined beam increases rapidly in a higher mode of HG and LG beam. We evaluate the efficiency of combining beams at different distances, noting that it increases with higher mode orders and reaches its maximum with the HG22 mode. Additionally, we explore the performance of higher-order Gaussian beam combinations under varying ground turbulence conditions. We observe that higher modes such as HG22 and LG22 are more susceptible to strong turbulence compared to lower modes.