We present a semiclassical theory of the linear and nonlinear optical response graphene. The emphasis is placed on graphene from standpoint underlying chiral symmetry. Bloch quasiparticles in low-energy limit around degeneracy points are dominantly chiral. It shown that this behavior conjunction with scale invariance Dirac results strong response. Explicit expressions for conductivity tensors derived based semiconductor equations (SBEs). terms agree result Kubo formulation. three main...

Graphene's giant nonlinear optical response along with its integrability has made it a vaunted material for on-chip photonics. Despite multitude of studies confirming strong nonlinearity, there is lack reports examining the fundamental processes that govern response. Addressing this gap in knowledge we analyse role experimental parameters by systematically measuring near-infrared spectral dependence, sub-picosecond temporal evolution and pulse-width dependence effective Kerr coefficient (n

Chirality refers to a geometric phenomenon in which objects are not superimposable on their mirror image. Structures made of nanoscale chiral elements can exhibit chiroptical effects, such as dichroism for left- and right-handed circularly polarized light, makes these structures highly suitable applications ranging from quantum information processing optics circular spectroscopy molecular recognition. At the same time, strong effects have been challenging achieve even synthetic optical...

Abstract We reveal that optical saturation of the low-energy states takes place in graphene for arbitrarily weak electromagnetic fields. This effect originates from diverging field-induced interband coupling at Dirac point. Using semiconductor Bloch equations to model electronic dynamics graphene, we argue charge carriers undergo ultrafast Rabi oscillations leading anomalous effect. The theory is complemented by a many-body study carrier relaxations graphene. It will be demonstrated...

This Rapid Communication presents a structure and full theoretical analysis to exploit the photon drag effect for THz signal generation in graphene layer integrated with plasmonic structure. The is composed of periodic array asymmetric nanoparticles patterned over layer. are designed accomplish two goals: field localization due resonance manipulating phase near effectively quasiparticles graphene. Combining asymmetry plasmon resonances nanoparticles, we show that an enhancement as large...

Here we report on our recent experimental efforts towards the design, fabrication and characterization of various metasurface structures that would allow spatial temporal control photon emission from atomic ensembles, as well state preparation solid quantum emitters. The emphasis is placed development two distinct categories structures: (i) Micro- meso-scale free-space self-polarizing confocal cavities formed by dielectric metasurfaces. (ii) flat hyper-gratings fabricated surface a diamond,...

The nonlinear optical behaviour of Graphene has become an important topic investigation as it adds another facet to its growing list electronic and mechanical properties. This work investigates the spectral dependence index refraction (n <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sub> ) graphene, spanning excitation in 800-1050 nm range, using Z-Scan technique.

In this paper, a general recipe is proposed to design an efficient graphene-integrated plasmonic structure for third harmonic generation. Specifically, the procedure integrated graphene-based ultraviolet light generator presented. order enhance field intensity at graphene layer, two distinct mechanisms are utilized. A multilayer Bragg used as perfect magnetic conductor make constructive interference between incident and reflected layer. periodic array of shaped resonant gold nanoparticles...

In a previous study by Shahir et al. , the permittivity profile of object under test (OUT) from electric fields measured outside OUT is accurately estimated considering region interest confined within boundary OUT. This proposes continuous‐wave multi‐view near‐field scattering tomography system at millimetre‐wave frequency range and reformulates sub‐space approach for reconstructing tomographic images while beyond boundary. The reconstructed enable one to localise boundaries. proposed also...

We report on the experimental realization of a chiral photonic-crystal structure which exhibits extreme intrinsic chira-optical activity. Formation quasi-bound-states-in-continuum allows selective reflection circular polarization states light and unconventionally preserves handedness upon reflection.

Hybrid quantum technologies aim to harness the best characteristics of multiple systems, in a similar fashion that classical computers combine electronic, photonic, magnetic, and mechanical components. For example, dots embedded semiconductor nanowires can produce highly pure, deterministic, indistinguishable single-photons with high repetition, while atomic ensembles offer robust photon storage capabilities strong optical nonlinearities be controlled single-photons. However, successfully...

We report on the experimental observation of chiral resonant modes via a free-space spin-preserving Fabry-Pérot cavity using Pancharatnam-Berry phase reflecting dielectric metasurface mirrors. Such meta-mirrors focus one spin state while diverging other and preserve helicity upon reflection.

Metasurface presents itself as a method to create flat optical devices that generate customizable wavefronts at the nanoscale. The traditional metasurface design process involves solving Maxwell's equations through forward simulations and implementing trial-and-error achieve desired spectral response. This approach is computationally expensive typically requires multiple iterations. In this study, we propose reverse engineering solution utilizes deep learning artificial neural network (DNN)....

With recent developments in the field of quantum computing and cryptography, establishing networks would allow for implementation post-quantum cryptographic protocols, distributed computing, sensor networks. Though, require use repeaters to preserve transmitted information over long distances. This work focuses on implementations frequency conversion which is used ensure signal a suitable transmission between different optical components system.

We report on experimental observation of pure chiral resonant modes in a spin-preserving Fabry-Pérot cavity enabled by geometric-phase reflective metasurfaces. The cavity, stabilizing one spin light, also preserves the helicity during round propagation light.

A lower bound on the total power scattered from a lossless and matched receiving antenna, for given incident wave, is presented. The vector spherical wave expansion used to describe scattering absorption mechanisms. Scattering main reason behind antenna absorption. This poses fundamental limit minimization of scattering. In other words, if we are extract any cannot be completely invisible, an inevitable consequence capturing process. To demonstrate phenomena, linear array optimized such that...

We describe the development and applications of a single-photon source based on quantum dot embedded in semiconductor nanowire, which can be precision-tuned to emit ∼1ns long photons at wavelengths that match transitions caesium D1 line. discuss interfacing such with atomic ensembles present our experimental results demonstrating new method tuning emission by condensing inert gas (N2) nanowire. Next, we how these single ∼895nm efficiently converted wavelength suitable for satellite QKD links...

Integrated photonics, an emerging branch of photonics in micron-scale proximity, has drawn tremendous attention due to its capability for the generation, manipulation and detection optical signals on a single chip. Microring modulators (MRMs) Mach-Zehnder (MZMs) are two frequently used photonic devices modern electro-optic communications that also play important role development computing systems [1] , [2] . However, their modulation technique which is based operational wavelength-peak drift...

This work applies the antenna formalism to a system formed by single quantum emitter and metasurface. The goal is design topology-optimized metasurfaces extract light from emitters embedded in dielectric materials.

Selective reflection and transmission of the different spin states light have been a long-explored area in nanophotonics quantum optics [1]. Applications are diverse encompass many areas such as information processing, engineering light-matter interactions novel types lasers. Particularly, cold atoms interact more strongly with circularly polarized lights. One can envision making cavities which only one state is trapped-but cannot be implemented conventional, metallic or dielectric-stack...

We describe the experimental progress and challenges of integrating a single photon source based on quantum dots embedded in semiconductor nanowires with cold-atom experiment which laser-cooled caesium atoms are loaded confined inside hollow-core micro-structured optical fiber. focus particular wavelength conversion photons between 895nm wavelengths suitable for satellite links (~794nm).

We report the generation of single-photon pulses from an InAsP quantum dot utilizing a CW diode laser and fiber electro-optic modulator as pump in lieu pulsed picosecond Ti;Sapphire laser.

We present our experimental demonstration of a polarization dichroic confocal cavity using pair vertically-mounted bi-layer dielectric metasurfaces consisting polarization-selective photonic-crystal mirror and metalens.