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The concept of transformation optics opens ways to control electromagnetic waves to achieve the invisibility cloak. Several extinguish works have been done to extend this method to design acoustic cloak. Previous acoustic cloaks are always involves inhomogeneous material. Here, a design of acoustic isolated cloak with homogeneous and anisotropic parameters is proposed using polygonal homogeneous transformation...
Optical microscopy is one of the most important scientific achievements in the history of mankind, and it is the most widely used technique for exploring the small world. However, as is well known, traditional lens-based optical microscopes suffer from the low imaging resolution λ/2 due to the diffraction limit. To overcome this obstacle, multiple innovative methods have been proposed during the past...
Exceptional point is a fundamental notion in quantum field theories and enables new functionalities in photonics. In this talk, I will discuss harnessing parity-time (PT) symmetry to realize optical exceptional points using the state-of-the-art integrated nanophotonics technology for novel optoelectronic functionalities. I will present unidirectional light transport and coherent light control at PT...
The development of integrated approaches for optical trapping, based on photonic or plasmonic structures fabricated on a chip, offers several compelling advantages. First, chip-based optical traps enable the trapping platform to be miniaturized. Second, the chip-based configuration lends itself naturally to the incorporation of sensing modalities. Third, optical nanostructures can generate strong...
In the follow paper I will discuss the recent progress in investigating the optical trapping dynamics of semiconductor nanowires and other high aspect-ratio nanoscale objects. Owing to their perculiar geometry, these objects present rich and complex behaviour that departs significantly from high-symmetry particles typically employed in tweezers experiments. Early work in the field focused on holographic...
Since Ashkin and colleagues reported the first stable three-dimensional (3D) optical trapping, or optical tweezers, created using radiation pressure from a single focused laser beam, optical tweezers have become an important tool for research in the fields of biology, physical chemistry and soft matter physics. Plasmonic nanoparticles have attracted increased attentions in recent years due to various...
Evanescent fields in optical micro- and nanofibres (MNF) have been proposed as efficient means for multiple microparticle trapping and prolusion [1, 2]. Here, we demonstrate the propulsion of 3 µm polystyrene particle chains in the evanescent fields of the fundamental and first higher order modes in an MNF system. The power at the waist was estimated to be 25mW in both cases Self-assembly and speed...
In surface-enhanced Raman scattering (SERS), the giant field enhancements generated by plasmonic nanostructures compensate for the relatively weak Raman scattering cross sections of many molecules. The effect is so substantial that Raman spectroscopy can be performed on single molecules (e.g., [1]). A structure that has proven especially effective for SERS is the dimer nanoantenna, i.e., two metal...
The miniaturization of optical components to the nanoscale has been an active field of research as the integration of optics with nanoelectronics has become increasingly imperative. One component of critical importance in this effort is the optical filter. Traditionally organic dyes have been used as micron-sized filters for display pixels, but these materials suffer from lifetime and stability issues...
Tip-enhanced optical spectroscopy (TERS) has been nowadays recognized as a powerful tool for nano-imaging and nano-analysis with a nanoscale spatial resolution far beyond the diffraction limit of light. A metallic probe tip plays important roles in confining and enhancing the incident light field due to the excitation of localized modes of surface plasmon polaritons at the nanoscale tip-apex. When...
Recently, the successful observation of topological transport of light boosts great enthusiasm to search new topological phases in artificial crystals for classical waves. By introducing anisotropic scatterers, here we propose a simple route to design topologically distinct photonic insulating phases that are characterized by opposite valley Chern numbers. The topological transition can be easily...
Being a key enabling technology, optofluidics allows precise light-based manipulation of liquids and solid particles on micrometer scales in fluidic environments and covers high potential to fabricate efficient integrated lab-on-a-chip devices. In many of these devices, the ability to control and to manipulate particles by light is of utmost importance. This comprises an all-optical treatment of particles,...
Liquid crystal microresonators are widely used in optics and photonics applications due to their small dimensions, very high Q-factor and their tunability properties. Microfluidics allows a precise generation of liquid crystal droplets characterized by narrow droplets diameter distributions. Droplets with different internal configurations, bipolar and radial, can be generated in the nematic and isotropic...
The optical properties of Si nanocone structures were theoretically studied by simulations. Fig. 1(a) illustrates the configuration of nanocone arrays used in the simulations. The nanocone arrays in our simulations is defined by three parameters: base diameter BD, period P and height H, and the base diameter is always set equal to the period. Simulations were performed to compare the normalized scattering...
A compact nitrogen dioxide (NO2) detection system is developed based on differential optical absorption spectroscopy (DOAS) using light emitting diode (LED) as the light source. Alumina ceramic, with properties of highly scattering and low absorption in the wavelength region of 430 ∼ 450 nm, is utilized as the gas cell to make the system extremely compact. Nitrogen dioxides with various concentrations...
Fiber-optic radiation sensors have been developed to detect gamma-rays generated from radioisotopes. Recently, many studies on the Cerenkov radiation in optical fibers without scintillator materials have been conducted to experimentally investigate their response characteristics against gamma-rays. The purpose of this study is to develop a Monte Carlo-based computer program in order to simulate the...
In this study, we have developed a system to measure vibration of microscale matter using an optical frequency comb fiber laser and optical microscope. A target sample measured in this study was a micro-tube made of silica glass. Its diameter, wall thickness, and the length of the micro-tube are 25 µm, 2.5 µm, and 2 cm, respectively. We used an optical frequency comb fiber laser, which has the repetition...
The recording density of optical storage systems has been increased by using the shorter wavelength of laser light and the higher numerical apertures of the objective lenses. However, the optical diffraction limit restricts these methods to get the higher recording density. Near-filed optical recording is one of the promising techniques because it has the potential to overcome this limitation. Many...
For health monitoring of civil structures, Brillouin scattering in optical fibers have been fully characterized and exploited. Conventionally, glass optical fibers have been mainly used as the sensor heads, but sometimes suffer from their low strain tolerance. One promising solution to overcome this drawback is the use of highly flexible plastic optical fibers (POFs). In this presentation, we review...
A novel design of double resonant plasmonic nanoantennas is proposed. Numerical simulations using finite-difference time-domain method show that the designed asymmetric H-shaped bowtie antenna can provide double resonances with a common electromagnetic hot spot in the antenna gap. These resonant modes are due to the plasmon hybridization in the asymmetric structure. In addition, a dual-narrow-band...
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