arXiv subjects

Jingbo Sun

Publications and source records attributed to Jingbo Sun.

44 records · Page 3Linked to original sources

arXiv2017

Orbital angular momentum beam instabilities in engineered nonlinear colloidal media

In this letter, we experimentally demonstrate the evolution of the optical vortex beams of different topological charges propagating in engineered nano-colloidal suspension of negative polarizability with saturable nonlinearities. Due to the high power of the incident beam, the modulation instability leads to an exponential growth of weak perturbations and thus splits the original vortex beam into a necklace beam consisting of several bright spots. The number of observed bright spots is intrinsically determined by the topological charge of the incident beam and agrees well with the predictions of our linear stability analysis and numerical simulations. Besides contributing to the fundamental science of light-matter interactions in engineered soft-matter media, this work opens new opportunities for dynamic optical manipulation and transmission of light through scattering media as well as formation of complex optical patterns and light filamentation in naturally existing colloids such as fog and clouds.

physics.optics↗

arXiv2016

Hyper-lithography

The future success of integrated circuits (IC) technology relies on the continuing miniaturization of the feature size, allowing more components per chip and higher speed. Extreme anisotropy opens new opportunities for spatial pattern compression from the micro- to nano-scale. Such compression, enabling visible light-based lithographic patterning not restricted by the fundamental diffraction limit,if realized,may address the ever-increasing demand of IC industry for inexpensive, all-optical nanoscale lithography. By exploiting strongly anisotropic optical properties of engineered nanostructures, we realize the first experimental demonstration of hyperlens-based photolithography, facilitating optical patterning below the diffraction limit using a diffraction-limited mask. We demonstrate that the diffraction-limited features on a mask can be de-magnified to form the subwavelength patterns on the photoresist using visible light. This unique functionality,enabled by the hyperbolic dispersive properties of the medium combined with the cylindrical shape of the structure, opens a new approach to the future all-optical nanolithography.

physics.optics↗

arXiv2016

M$^2$I: Channel Modeling for Metamaterial-Enhanced Magnetic Induction Communications

Magnetic Induction (MI) communication technique has shown great potentials in complex and RF-challenging environments, such as underground and underwater, due to its advantage over EM wave-based techniques in penetrating lossy medium. However, the transmission distance of MI techniques is limited since magnetic field attenuates very fast in the near field. To this end, this paper proposes Metamaterial-enhanced Magnetic Induction (M$^2$I) communication mechanism, where a MI coil antenna is enclosed by a metamaterial shell that can enhance the magnetic fields around the MI transceivers. As a result, the M$^2$I communication system can achieve tens of meters communication range by using pocket-sized antennas. In this paper, an analytical channel model is developed to explore the fundamentals of the M$^2$I mechanism, in the aspects of communication range and channel capacity, and the susceptibility to various hostile and complex environments. The theoretical model is validated through the finite element simulation software, Comsol Multiphysics. Proof-of-concept experiments are also conducted to validate the feasibility of M$^2$I.

cs.OH↗

arXiv2015

High-Efficiency All-Dielectric Metasurfaces for Ultra-Compact Beam Manipulation in Transmission Mode

Metasurfaces are two-dimensional optical structures enabling complete control of the amplitude, phase, and polarization of light. Unlike plasmonic metasurfaces, planar silicon structures facilitate high transmission, low losses and compatibility with existing semiconductor technologies. Here, we report an experimental demonstration of high-efficiency polarization- sensitive dielectric metasurfaces with full 2pi phase control in transmission mode at telecommunication wavelengths. Such silicon metasurfaces are poised to enable a versatile optical platform the realization of all-optical circuitry on a chip.

physics.optics↗

arXiv2015

Inhomogeneous All-Dielectric Magnetic Metamaterials

Anomalous field enhancement accompanied by resonant absorption phenomenon was originally discussed in the context of plasma physics and in applications related to radio-communications between the ground and spacecraft returning to Earth. Indeed, there is a critical period of time when all communications are lost due to the reflection/absorption of electromagnetic waves by the sheath of plasma created by a high speed vehicle re-entering the atmosphere. While detailed experimental studies of these phenomena in space are challenging, the emergence of electromagnetic metamaterials enables researchers exceptional flexibility to study them in the laboratory environment. Here, we experimentally demonstrated the localized field enhancement of the electromagnetic wave obliquely incident on a Mie-resonance-based inhomogeneous metamaterials with magnetic permeability gradually changing from positive to negative values.

physics.optics↗

arXiv2014

Metamaterial all-optical switching based on resonance mode coupling in dielectric meta-atoms

All-optical switching based on optical nonlinearity must undergo complex processes of light-mater interaction in atom and electron scale, so a relative high power and long response time is required, that construct main bottlenecks in all-optical technology. In this paper, we propose a new mechanism for building all-optical switching based on a change resonance modes of meta-atoms in metamaterials, not involved optical nonlinearity of materials. A metamaterial composed of cubic dielectric meta-atoms periodically embedded in a background matrix is designed and constructed. All-optical switch functionality by modulating the resonance modes in meta-atoms utilizing a vertical direction switch light whose power is the same value with that of the signal light is demonstrated in microwave range theoretically and experimentally. This results represent a significant step towards obtaining all-optical switching devices with extremely low threshold power and high switching speed.

cond-mat.mtrl-sci↗

arXiv2014

Experimental Demonstration of Non-Resonant Hyperlens in the Visible Range

A metamaterial hyperlens offers a unique solution to overcome the diffraction limit by transforming evanescent waves responsible for imaging subwavelength features of an object into propagating waves. However, the first realizations of optical hyperlenses were limited by a narrow working bandwidth and significant resonance-induced loss. Here, we report the first experimental demonstration of a non-resonant waveguide-coupled hyperlens operating in the visible wavelength range. A detailed investigation of various materials systems proves that a radial fan-shaped configuration is superior to the concentric layer-based configuration in that it relies on non-resonant negative dielectric response, and, as a result, enables broadband and low-loss performance in the visible range.

physics.optics↗

arXiv2010

Negative refraction at deep-ultraviolet frequency in monocrystalline graphite

Negative refraction is such a prominent electromagnetic phenomenon that most researchers believe it can only occur in artificially engineered metamaterials. In this article, we report negative refraction for all incident angles for the first time in a naturally existing material. Using ellipsometry measurement of the equifrequency contour in the deep-ultraviolet frequency region (typically 254 nm), obvious negative refraction was demonstrated in monocrystalline graphite for incident angles ranging from 20o to 70o. This negative refraction is attributed to extremely strong anisotropy in the crystal structure of graphite, which gives the crystal indefinite permeability. This result not only explores a new route to identifying natural negative-index materials, but it also holds promise for the development of an ultraviolet hyperlens, which may lead to a breakthrough in nanolithography, the most critical technology necessary for the next generation of electronics.

cond-mat.mtrl-sci↗