Resonant systems with high bandwidth The performance of an active system, whether it is optical, electrical, or mechanical, often described by its quality ( Q ) factor. Typically, one learns the rule that higher factor, sharper resonance—that is, device reduced. Tsakmakidis et al. show this indeed case, but only for symmetric systems. However, case asymmetric (or nonreciprocal) systems, need not be obeyed. They theoretically more a system wider can be. effect raises prospect designing high-...

The dynamic erosion effect of the corrosive medium formed by aqueous solution and CO2 gas on rock will lead to decline mechanical properties seriously threaten long-term stability durability mass in reservoir area. In this paper, a test method is proposed study deterioration rock, based gas–liquid cycle. A total 210 limestone samples were tested under various cycles (0, 5, 10, 15, 20, 25, 30 cycles). systematic analysis key physical related degradation behavior (Young's modulus, uniaxial...

Design of photonic crystal fibers (PCFs) for application broad-band dispersion compensation is investigated by using an improved design model based on combination a rigorous vector solver modal properties and scaling approach characteristics. The newly designed PCF shown to exhibit large normal up -474.5 ps/nm/km, nearly five times conventional compensating fibers, compensate single-mode within /spl plusmn/0.05 ps/nm/km over 236-nm wavelength range. Furthermore, the methodology can be...

A two-stage genetic algorithm (GA) with a floating mutation probability is developed to design two-dimensional (2D) photonic crystal of square lattice the maximal absolute band gap. The unit cell divided equally into many pixels, and each filling pattern pixels two dielectric materials corresponds chromosome consisting binary digits 0 1. As numerical example, GA gives 2D GaAs structure relative width gap about $19%.$ After further optimization, new found an much larger than those reported before.

The characteristics of an imaging system formed by a left-handed material (LHM) slab finite length are studied, and the influence on image quality is analyzed. Unusual phenomena such as surface bright spots negative energy stream at side observed explained cavity effects plasmons excited evanescent components incident field. For thin LHM slab, found rather sensitive to slab; bottom may stretch plane degrade quality.

Based on a modal expansion of electromagnetic fields, rigorous method for analyzing surface plasmon polaritons (SPPs) periodically corrugated metal has been formulated in this paper. This takes into account the finite conductivity as well higher-order modes within grooves structure, thus is able to accurately calculate loss these spoof SPPs propagating along structured surface. In terahertz (THz) frequency range, properties dispersion and Al surfaces are analyzed. For at THz frequencies,...

A photonic crystal fiber (PCF) with circular air holes in the cladding and elliptical core is proposed. According to calculation, both ultrahigh birefringence (larger than 0.01) ultralow confinement loss (less 0.001dB/km) can be achieved simultaneously over a large wavelength range for PCF only four rings of cladding. The this effectively reduced while almost remains same. proposed design solution tradeoff between originally reported highly birefringent elliptical-hole PCF. Moreover, an...

Abstract A plasmonic nanostructure (PNS) which integrates metallic and dielectric media within a single structure has been shown to exhibit specific properties are considered useful in refractive index (RI) sensor applications. In this paper, the simultaneous realization of sensitivity tunability optical PNSs consisting alternative Ag nanosphere/nanorod array have proposed compared by using three-dimensional finite element method. The system can support hybrid modes localized surface...

Abstract Metasurfaces are capable of fully reshaping the wavefronts incident beams in desired manners. However, requirement for external light excitation and resonant nature their meta-atoms, make challenging on-chip integration. Here, we introduce concept design a fresh class metasurfaces, driven by unidirectional guided waves, arbitrary wavefront control based on unique dispersion properties waves rather than meta-atoms. Upon experimentally demonstrating feasibility our designs microwave...

A novel elliptical-hole photonic crystal fiber (PCF) with double defect is theoretically investigated, and its high birefringence [including both the phase-index (PIB) group-index (GIB)] demonstrated, which can reach an order of 10 <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">-2</sup> Such a PCF especially have very PIB, negligible GIB in small band normalized frequencies. The PIB this much higher than that circular-hole defect, under...

High birefringence induced by elliptical air hole photonic crystal fibers (EHPCFs) is analyzed numerically using the finite-element method. Statistical correlations between and various parameters are obtained. We found that complex better than of a circular one to obtain high in fibers. Our suggested structures can considerably enhance EHPCFs show be as 1.1294×10−2, which higher obtained from conventional step-index fiber (5 × 10−4), holes PCF (3.7×10−3), hollow (2.35 10−3).

High-order modes of spoof surface plasmon polaritons (SPPs) on the periodically corrugated metal surfaces are investigated theoretically with modal expansion method. An analytical expression for condition existence high-order is presented. The properties such as dispersion and fleld pattern analyzed detailedly, from which it seems that propagation SPPs along mainly based coupling between open groove cavities.

Surface magnetoplasmons (SMPs) in a basic physical model for the terahertz regime, which consists of semi-infinite magnetized semiconductor with dielectric cladding terminated by metal slab, are theoretically investigated. The dispersion properties such SMPs analyzed and examined detail. It is shown that may follow three different kinds diagrams, depending on applied dc magnetic field intensity. Complete one-way propagation operates within band gap available SMPs, bandwidth reaches maximum...

Subwavelength guiding of channel plasmon polaritons (CPPs) is realized by a properly structured metallic groove at frequencies far below the plasma frequency metal. Compared with CPPs visible frequencies, more versatile physical mechanisms can be introduced in these surface patterning, so that they exhibit superior features as CPPs, while eliminating potential drawbacks latter. Such designer are explained physically effective-index method and verified experimentally microwave regime.

We demonstrate that one-way electromagnetic modes could be sustained by the edge of a gyromagnetic photonic crystal slab triangular lattice under an external dc magnetic field. The applied field breaks time-reversal symmetry three-dimensional system, and thus original degeneracy point in k space, at which two dispersion surfaces intersect, is lifted, resulting band gap below light cone. At this gap, mode localized horizontally to edge, while confined index contrast vertical direction.

We apply the concept of spoof surface plasmon polaritons (SPPs) to design differential microstrip lines by introducing periodic subwavelength corrugations on their edges. The dispersion relation and field distribution those are analyzed numerically. And then through designing practical coupling circuits, we found that compared with conventional lines, electromagnetic can be strongly confined inside grooves corrugated so crosstalk between pair adjacent is greatly reduced, conversion from...

The explicit dispersion equation for a one-dimensional periodic structure with alternative layers of left-handed material (LHM) and right-handed (RHM) is given analyzed. Some unusual phenomena such as spurious modes complex frequencies, discrete photon tunneling are observed in the band structure. existence frequencies common problem calculation photonic crystal. Discrete may exist regardless whether optical length LHM layer cancels RHM or not. Physical explanation significance (with real...

In this paper, we demonstrate highly directive emission based on anisotropic metamaterials with spatial dispersion of very narrow hyperbola. By embedding the source inside a slab such material, emitted energy, both and outside is concentrated around normal slab, perfect far-field radiation thus achieved. This effect verified experimentally in microwave domain, directivity that far larger than best one to our knowledge obtained from constructed antenna.

Surface plasmon polaritons (SPPs) propagating along a structure consisting of single row metallic wedges periodically protruding out planar surface are investigated theoretically. It is shown that such can sustain mode spoof SPPs in the terahertz region, whose fields highly confined transverse plane. The guiding possesses excellent properties as good modal shape, large propagation length, and low bending loss, making it promising candidate for routing radiation integrated circuits.

Nowadays, the terahertz (THz) communication is believed to be a potential solution blackout for reentry vehicles. In this paper, numerical hypersonic fluid model was introduced obtain realistic plasma sheaths. The onboard antenna which installed on wall assumed conformal. transmission of obliquely incident THz waves in sheaths analyzed. According power coefficient decreases with increase speed since both electron density and collision frequency near speed. addition, relation between wave...

Abstract Biodegradable poly(lactic acid)/poly(butylene adipate‐co‐terephthalate) (PLA/PBAT) blends have poor compatibility, and reactive compatibilization is the most effective approach to improve their compatibility. In this study, lysine diisocyanate (LDI) employed as a compatibilizer interfacial interactions within PLA/PBAT at various ratios (30/70, 50/50, 70/30). The effects of LDI on mechanism, thermodynamic behavior, mechanical properties, phase morphology are thoroughly investigated....

In this paper, a rigorous method for analyzing surface plasmon polaritons (SPPs) on periodically corrugated metal wire has been formulated, based modal expansion of electromagnetic fields. Compared with the previous method, our takes into account finite conductivity as well higher-order modes within grooves in expansion, thus is able to accurately calculate loss these spoof SPPs propagating along wire. terahertz frequency range, properties Al wires are analyzed. The grows significantly...

The spatial dispersion properties of a one-dimensional metal photonic crystal have been analyzed and five types curves shown at normalized frequency less than 1. It is demonstrated that by exploiting parabolalike behavior, slab can be used to realize an exactly 50∕50 beam splitter.