Alina Karabchevsky

Alina Karabchevsky
Ben-Gurion University of the Negev | bgu · School of Electrical and Computer Engineering

Professor

About

144
Publications
27,093
Reads
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1,688
Citations
Additional affiliations
October 2015 - February 2016
Ben-Gurion University of the Negev
Position
  • Group Leader
October 2013 - August 2015
University of Southampton
Position
  • Research Associate
April 2008 - April 2012
Ben-Gurion University of the Negev
Position
  • PhD Student

Publications

Publications (144)
Article
Full-text available
Photonics integrated circuitry would benefit considerably from the ability to arbitrarily control waveguide cross-sections with high precision and low loss, in order to provide more degrees of freedom in manipulating propagating light. Here, we report a new method for femtosecond laser writing of optical-fiber-compatible glass waveguides, namely sp...
Article
Full-text available
Circular dichroism spectroscopy can be optimized to measure the scattering circular dichroism response of a single chiral nanostructure with a single shot.
Article
Full-text available
Advanced photonic tools may enable researchers and clinicians to visualize, track, control, and manipulate biological processes at the single-cell level in space and time. Biological systems are complex and highly organized on both spatial and temporal levels. If biological entities are to be studied, perturbed, engineered, or healed, key-players i...
Preprint
Full-text available
Optical microfibers finds new applications in various fields of industry, which in turn requires wear resistance, environmental friendliness and ease of use. However, optical microfibers are fragile. Here we report a new method to prolong the microfiber lifetime by modifying its surface with green-extracted graphene overlayers. Graphene films were...
Preprint
Full-text available
Photonics integrated circuitry would benefit considerably from the ability to arbitrarily control waveguide cross-sections with high precision and low loss, in order to provide more degrees of freedom in manipulating propagating light. Here, we report on a new optical-fibres-compatible glass waveguide by direct laser writing, namely spherical phase...
Preprint
Full-text available
Advanced photonic tools may enable researchers and clinicians to visualize, track, control and manipulate biological processes at the single-cell level in space and time. Biological systems are complex and highly organized on both spatial and temporal levels. If we are to study, perturb, engineer or heal biological entities, we must be able to visu...
Preprint
Full-text available
Conventional fabrication methods to produce graphene are cumbersome, expensive and are not ecology friendly. This is due to the fact that a large volume of raw materials requires a large number of acids and alkalis, which in turn requires special disposal. Therefore, it is necessary to develop new technologies or refine existing technologies for th...
Preprint
Full-text available
Neural networks are one of the first major milestones in developing artificial intelligence systems. The utilisation of integrated photonics in neural networks offers a promising alternative approach to microelectronic and hybrid optical-electronic implementations due to improvements in computational speed and low energy consumption in machine-lear...
Article
The generation of spatial rogue waves, or "hot spots," is demonstrated experimentally in the passively Q-switched Nd:YAG laser system operating in a low-power regime well below the self-focusing limit. Here, we report the dependence of rogue wave statistics on the number of transverse modes that interact in the laser cavity. Our observations show t...
Article
Optical waveguides are widely used in integrated photonic circuitry for a variety of applications such as on‐chip lasers, filters, light sources, amplifiers. Such waveguides suffer from high reflection which harms the transparency of the device and, therefore, its efficiency. In article number 2100130, Alina Karabchevsky and her team from the Schoo...
Article
Nature has long inspired scientists and engineers to develop transparent surfaces via constructing anti‐reflective surfaces. In absence of anti‐reflection (AR) coating, silicon reflects about 35% of light for a single interface air−silicon. Here, inspired by jellyfish anti‐reflective eyes, a man‐made anti‐reflective surface on the facet of the wave...
Chapter
This chapter overviews the principles of the spontaneous emission rate increase, that is the Purcell effect, in relation to the photonic parity-time (PT) symmetry. Being focused on the system of coupled PT-symmetric optical waveguides, we consider behaviors of the Purcell factor in PT-symmetric and broken-PT-symmetric regimes. Surprisingly, excepti...
Article
Chemiluminophores are entities, which exhibit wide-band light emission without any external light source, just caused by a chemical reaction. Since chemiluminescence usually yields to unfavorable competition with other channels of chemical energy dissipation, plasmonic nanoparticles can be employed to enhance the chemiluminescence quantum yield via...
Preprint
Full-text available
This chapter overviews the principles of the spontaneous emission rate increase, that is the Purcell effect, in relation to the photonic parity-time (PT) symmetry. Being focused on the system of coupled PT-symmetric optical waveguides, we consider behaviors of the Purcell factor in PT-symmetric and broken-PT-symmetric regimes. Surprisingly, excepti...
Chapter
Passive and active materials platforms are building blocks of an essential element of photonic integrated circuitry (PIC)-waveguide. Due to their small dimensions, waveguides allow miniaturization and design of efficient optical components on a chip. Therefore, choosing the right material for the waveguide is crucial for photonic integrated circuit...
Conference Paper
Optical properties of silver nanoparticles obtained via physical vapor deposition on transparent dielectric substrates have been simulated numerically and investigated experimentally. Additional laser treatment of MEC substrate was employed to improve chemical and mechanical stability of the films and made them suitable for chemiluminescence experi...
Article
Correction for ‘Photonic hook formation in near-infrared with MXene Ti 3 C 2 nanoparticles’ by Marat Spector et al. , Nanoscale Adv. , 2020, 2 , 5312–5318, DOI: 10.1039/D0NA00485E
Conference Paper
Tuning electric and magnetic response of dielectric structures at the nanoscale is a very important task nowadays. Multipole decomposition is a useful instrument to analyze and then control an opical response. Here we show the way to excite magnetic octupole moment by nanostructuring dielectric scatterer in near-IR spectral range. This response lea...
Preprint
Full-text available
We study the spontaneous emission rate of a dipole emitter in PT -symmetric environment of two coupled waveguides using the reciprocity approach generalized to non-orthogonal eigenmodes of non-Hermitian systems. Considering emission to the guided modes, we define and calculate the modal Purcell factor composed of contributions of independent and in...
Article
We study the spontaneous emission rate of a dipole emitter in PT-symmetric environment of two coupled waveguides using the reciprocity approach generalized to nonorthogonal eigenmodes of non-Hermitian systems. Considering emission to the guided modes, we define and calculate the modal Purcell factor composed of contributions of independent and inte...
Article
Full-text available
The creation of single photon sources on a chip is a mid-term milestone on the road to chip-scale quantum computing. An in-depth understanding of the extended multipole decomposition of non-isolated sources of electromagnetic radiation is not only relevant for a microscopic description of fundamental phenomena, such as light propagation in a medium...
Article
Semiconductor transistor‐sensors are considered the most widely manufactured device in history. Being invented to switch electronic signals they revolutionized electronics. However, electric switches are hampered by damage from very brief electrical and thermal effects or electromagnetic interference. In article number 2000769, Alina Karabchevsky a...
Article
Full-text available
MXene, a recently developed 2D material, has attracted considerable attention because of its graphene-like but highly tunable properties. It appears that the metallic properties of MXene titanium carbide are pronounced in the near-infrared with well-defined localised surface plasmon resonance (LSPR). Here, we report on the curved photonic nanojet,...
Article
Full-text available
On-chip nanophotonic devices are a class of devices capable of controlling light on a chip to realize performance advantages over ordinary building blocks of integrated photonics. These ultra-fast and low-power nanoscale optoelectronic devices are aimed at high-performance computing, chemical, and biological sensing technologies, energy-efficient l...
Article
In this letter, we report the experimental observations of tunable curved photonic nanojet (photonic hook) generated by 5 μm polydimethylsiloxane microcylinder deposited on a silicon substrate and illuminated by 405 nm laser beam. A moveable opaque aluminum-mask is mounted in front of the microcylinder implementing partial illumination and impartin...
Article
Full-text available
An on-chip optical vortex detector based on spin-Hall nanoslits is reported. The detector is sensitive to the spin of the incoming beam and can simultaneously record the polarization and phase singularity. Although the reported device relies on fast decaying surface plasmons, it represents an important step forward in the development of optical vor...
Article
Semiconductor transistors for sensors are considered the most widely manufactured device in history. Being invented to switch electronic signals they revolutionized electronics and paved the way for smaller and cheaper sensors, radios, calculators, and computers. However, electric switches are hampered by damage from very brief electrical and therm...
Article
Full-text available
Molecular overtones stretching modes that occupy the near-infrared (NIR) are weak compared to the fundamental vibrations. Here we report on the enhancement of absorption by molecular vibrations overtones via electromagnetic field enhancement of plasmonic nanoparallelepipeds comprising a square lattice. We explore numerically, using finite element m...
Article
Full-text available
Building blocks of photonic integrated circuitry, optical waveguides, have long been considered transparent. However, the inevitable Fresnel reflection from waveguide facets limits their transparency. This limitation becomes more severe in high-index waveguides in which the transparency may drop to 65%. We overcome this inherent optical property of...
Article
Full-text available
Tuning the near-field using all-dielectric nano-antennae offers a promising approach for trapping atoms, which could enable strong single-atom/photon coupling. Here we report the numerical study of an optical trapping of single Cs atom above a waveguide with silicon nano-antenna which produces a trapping potential for atoms in a chip-scale configur...
Article
Full-text available
Rapid, sensitive and reliable detection of aromatic amines - toxic manufacturing byproducts - have been previously achieved with molecular vibrations in Mid-infrared (Mid-IR) region. However, Mid-IR spectroscopic tools are hampered by a need to prepare the samples and the sensor cost. Here we develop an affordable label-free sensor on a chip, opera...
Article
Full-text available
Optical forces applied on an object or cell in a non-destructive manner have revolutionised the scientific instruments. The optical tweezers, atomic traps are just two representative examples. Of particular interest for non-destructive manipulation, are curved forces such as photonic hooks, however they extremely weak in a low-contrast media. Here...
Preprint
Full-text available
In this letter, we report on numerical study, fabrication and experimental observations of tunable photonic nanojet and photonic hook. Here, the curved photonic nanojets (photonic hooks) are generated by single mesoscale microcylinder that we fabricated from polydimethylsiloxane (PDMS), upon its boundary illumination and adjustable area at an incid...
Article
Full-text available
The development of new approaches to tuning the resonant magnetic response of simple all‐dielectric nanostructures is very important in modern nanophotonics. Here, it is shown that a resonant magnetic octupole (MOCT) response can be obtained by dividing a solid rectangular silicon block to a quadrumer structure with the introduction of narrow gaps...
Article
Spatial resolution of conventional optics, which is necessary for nondestructive trapping of micro-objects, is limited by diffraction to a value equal to half of the radiation wavelength. Despite this limitation, using optical methods is one of the main directions in biological and biomedical researches because only these methods have a minimal imp...
Article
Full-text available
Here we use multipole decomposition approach to study optical properties of a silicon nanocylinder in different lossless media. We show that resonant peaks of multipole moments experience red shift, smoothing and broadening. Worth noting that electric multipoles experience bigger red shift than their magnetic counterparts. Our results can be applie...
Article
Full-text available
The ability of all-dielectric nanostructures to perform exotic photonics effects is with superior efficiency compared to their metallic counterparts. Free from joules losses, high-index dielectrics support comparable excitation of electric and magnetic resonances and pave a way to advanced technologies of light energy manipulation. One of the most...
Article
Full-text available
All-dielectric nanophotonics attracts more and more attention nowadays due to the possibility to control and configure light scattering on high-index semiconductor nanoparticles. It opens a room of opportunities for the designing novel types of nanoscale elements and devices, and paves a way to advanced technologies of light energy manipulation. On...
Article
Full-text available
Dielectric nanophotonics is the modern and very relevant field of optics. In this work we use the recently reported Cartesian multipole decomposition approach for all-dielectric metasurfaces [1] to study optical properties of the silicon metasurface at the nanoscale. This metasurface consists of crystalline silicon cubes rotated by 45° around the a...
Preprint
Tuning the near-field using all-dielectric nano-antennae offers a promising approach for trapping atoms, which could enable strong single-atom/photon coupling. Here we report the simulation results of an optical trapping concept, in which a silicon nano-antenna produces a trapping potential for atoms in a chip-scale configuration. Using counter-pro...
Article
Full-text available
The mid-infrared spectrum can be recorded from almost any material, making mid-infrared spectroscopy an extremely important and widely used sample characterization and analysis technique. However, sensitive photoconductive detectors operate primarily in the near-infrared (NIR), but not in the mid-infrared, making the NIR more favorable for accurate...
Preprint
Full-text available
Mid-infrared spectrum can be recorded from almost any material making the mid-infrared spectroscopy an extremely important and widely used sample characterization and analytical technique. However, sensitivity photoconductive detectors operate primarily in the near-infrared (NIR) but not in the mid-infrared making the NIR more favorable for accurat...
Article
Full-text available
Resonant coupling between plasmonic nanoantennas and molecular vibrational excitations is employed to amplify the weak overtone transitions that reside in the near-infrared. We explore for the first time the differential extinction of forbidden molecular overtone transitions coupled to the localized surface plasmons. We show a non-trivial interplay...
Preprint
Full-text available
The development of new approaches to tuning the resonant magnetic response of simple all-dielectric nanostructures is very important in modern nanophotonics. Here we show that a resonant magnetic octupole (MOCT) response can be obtained by dividing a solid rectangular silicon block to an oligomer structure with the introduction of narrow gaps betwe...
Article
Full-text available
Here, we propose the concept of an “optical vacuum cleaner” for optomechanical manipulation of nanoparticles. We utilize a dielectric cuboid to generate an optical gradient force exerted on the nanoparticles for particle’s hovering and trapping. We show that the permittivity contrast between the particle and the nanohole leads to the deep subwavele...
Article
Full-text available
In the Supplementary Material, we prove the validity of the dipole-quadrupole approximation to obtain the conditions of the transverse scattering. The coincidence of the electric dipole Fano profile with the quadrupoles off-resonance and their role in obtaining the transverse scattering phenomenon have been clarified. We also investigate the substr...
Article
Full-text available
We explore the discrete nature of waveguide modes and the effective medium concept to achieve an ultra-compact highly efficient mode conversion device in a high-index platform such as a silicon waveguide. The proposed device is based on a co-directional coupler that has a periodic variation in its refractive index along the propagation direction. T...
Conference Paper
Full-text available