The authors demonstrate a composite microring laser formed by immersing silica microfiber knot in rhodamine 6G dye solution. When the molecules are evanescently pumped 532nm wavelength pulses guided along 350μm diameter knot, lasing oscillation occurs inside coupled closed-ring microcavity with linewidth of about 0.06nm. Laser emission around 570 and 580nm wavelengths, which is back into microfiber, observed threshold 9.2μJ∕pulse. use cavity suggests convenient efficient approach to both...

We demonstrate a compact hybrid structure red-green-ultraviolet three-color laser consisting of three distinct semiconductor nanowires (CdSe, CdS and ZnO) attached to silica microfiber, which is pumped by 355 nm wavelength pulses. The exciting the collection photoluminescence (PL) are implemented means evanescent coupling through same microfiber. When pump energy higher than 1.3 microJ, spatially spectrally lasing groups can be measured at output port simultaneously. approach extended other...

Bending losses of nanofibers or nanowires with circular 90 degrees bends are simulated using a three-dimensional finite-difference time-domain (3D-FDTD) method. Dependences bending on wavelength and polarization guided light investigated, as well the diameters, refractive indices, radii nanowires. The acceptable (approximately 1 dB/90 degrees) predicted in glass, polymer, semiconductor down to micrometer level may offer valuable references for assembling highly compact photonic integrated...

Endface output patterns of micro/nanofibers (MNFs) are simulated using a Three-Dimension Finite-Difference Time-Domain (3D-FDTD) method. The intensity distribution and beam widths near- or farfield freestanding silica tellurite MNFs with flat, angled, spherical tapered endfaces in air and/or water obtained. It shows that, for subwavelength-diameter MNF, highly confined can be obtained the near field, width tuned by ratio fiber diameter light wavelength minimum smaller than wavelength....

Utilizing the diffraction property of output light from micro/nano fibers (MNFs), a new scheme based on MNF array to focus optical beams with subwavelength resolution in far field is proposed. By using three-dimensional finite-difference beam-propagation method (FD-BPM), we investigated interference effect MNFs during propagation. The numerical stimulation demonstrates focusing spot FWHM 0.43 lambda at distance 9 endface array. effects characteristics array, MNFs, and input are analyzed detail.

A novel direct-laser writing fabrication process for microaxicons is demonstrated.A fiber-axicon-generated Bessel beam was utilized to write on UV-curable optical epoxy form new axicons and axicon arrays, geometrical parameters of the replicated were analyzed in terms both apex angle proximity axicons.The shape fabricated demonstrated be controllable through laser exposure, proximity, source axicon, are capable generating a quality with an excellent focusing performance.

We propose a mechanism for subwavelength focusing at optical frequencies based on the use of tapered microtube fabricated from glass capillary tube. Using coherent illumination 671 nm and near-field scanning microscope probe which was mounted three-axis piezonanopositioning stage, sequence two-dimensional intensity profiles were obtained. Our experimental results reveal smallest focal spot with near diffraction-limited full width half-maximum ∼435 (0.65λ) distance ∼1.47 μm (2.2λ) output end...

We discuss mode-entangled states based on the optical transverse modes of field propagating in multi-mode waveguides, which are classical analogs quantum entangled states. The discussed detail, including violation Bell inequality and correlation properties pulses' group delays. research these may be important, for it not only provides useful insights into fundamental features entanglement, but also yields new computation communication.

We propose a two-colour scheme of atom guide and 1D optical lattice using evanescent light fields TE00 TE01 transverse modes in an waveguide. The waveguide carries red-detuned blue-detuned light, with both far from resonance. potentials can be transformed to each other by Mach–Zehnder interferometer accurately control mode transformation. This might provide new approach realize flexible transition between the guiding trapping states atoms.

We demonstrate the optical manipulation of biological particles using a low-order LP21 fiber mode. The focused four-lobed mode distribution was theoretically and experimentally found to be effective in tweezer applications, including selective cellular pick-up, pairing, grouping or separation, as well rotation cell dimers clusters. Our proposed theoretical model estimates both translational dragging force rotational torque good accordance with experimental data. With simple all-fiber...

Coherent diffractive imaging (CDI) is a lensless technique and can achieve resolution beyond the Rayleigh or Abbe limit. The ptychographical iterative engine (PIE) CDI phase retrieval algorithm that uses multiple diffraction patterns obtained through scan of localized illumination on specimen, which has been demonstrated successfully at optical X-ray wavelengths. In this paper, general PIE (gPIE) presented with an He—Ne laser light dataset. This not only permits removal accurate model...

We demonstrate an efficient method for far-field subwavelength focusing by a novel two-component axicon structure. Annular beams generated fiber are focused using micro-cone reflector, creating quasi-Bessel beam with high convergence angle of up to 40°. A center focal spot diameter 0.41λ was achieved at power efficiency over 40%, depth 9λ and working distance as long 35 μm. further that experimental knife-edge measurements mapping the intensity agree numerical simulations This shows...

A finite-difference time-domain method is developed to treat a nearly-free-electron metal by rewriting the Maxwell's equations into three coupled partial differential for vector functions. The used calculate band structures of two-dimensional metallic photonic crystals, and numerical results are compared with those obtained other methods. new time-stepping formulae also investigate defect modes calculating transmission spectrum.

Based on extended Richards-Wolf theory for axisymmetric surfaces and the inverse Faraday effect, we propose generation of a purely longitudinal magnetization needle by focusing Gaussian annular azimuthally polarized beams with spherical mirror. The obtained has length varying hundreds to thousands wavelengths while keeping lateral size under 0.4λ, corresponding aspect ratio can easily reach more than 2000. It may be first time that whose is over 500 been achieved. approximate analytical...

Based on the inverse Faraday effect, tunable light-induced magnetization chains are investigated by focusing narrow annular azimuthally polarized vortex beams with a 4π system composed of double parabolic mirrors. Using Richards-Wolf vector diffraction theory, approximate analytical expressions all parameters theoretically calculated, realizing that tunable. The calculated results show independent amplitude distribution function incident beam and apodization factor system. Hence, different...

This paper addresses the difficult problem of measuring attitude a high-spinning projectile and presents novel method for estimating pitch yaw angles in flight. The is based on analysis external moment rotating during flight theoretical derivations obtained from dynamics’ equations. First, principle zero-crossing introduced, which explains process geomagnetic azimuth roll measurements by non-orthogonal sensor combination. Then, dynamics constraint equations between Euler flight-path angle,...

This paper discusses the study of multimode evolution microfiber taper and its potential application micromixer in lab-on-a-chip. By using numerical simulation, interference effects are demonstrated transition a micro-nano fiber. Due to leaked optical energy gasifies solution surrounding produces air bubbles, laminar flow effect is destroyed with help disturbance bubble two solutions mixed quickly. Therefore, it will be used microfluidic platform for chemical analysis & testing,...

On the basis of invariant formulation, we find quantum and classical exact solutions corresponding total phase for relativistic charged Klein-Gordon (KG) field in a time-dependent spatially homogeneous electric field. The includes both dynamical geometric phases (Aharonov-Anandan phases). connection between is then obtained. From this discuss condition under which KG can be defined.

A fully optical method to perform any quantum computation with waveguide modes is proposed by supplying the prescriptions for a universal set of gates. The proposal based on implementing bit two normal multi-mode waveguides. gates has potential being more compact and easily realized than other implementations, since it planar lightwave circuit technology can be constructed using Mach-Zehnder interferometer configurations having semiconductor amplifiers very high refractive nonlinearity in their arms.

Abstract Aiming at the problems of long calculating time and cumulative error in traditional projectile impact point prediction methods, a method based on BP neural network is proposed this paper. In order to avoid local minimum slow convergence speed, genetic algorithm used optimize initial weights thresholds network. The model for predicting obtained by training with large number flight state parameters information, simulation test carried out. results show that can predict high accuracy,...