This article demonstrates theoretical design of ultracompact all-optical AND, NAND, OR, and NOR gates with two-dimensional nonlinear photonic crystal slabs. Compound Ag-polymer film a low refractive index large third-order nonlinearity is adopted as our material cavities relatively high quality factor about 2000 designed on this polymer slab. Numerical simulations show that logic pump-power in the order tens MW/cm2 can be achieved. These results may provide very useful schemes approaches for...

An ultrafast all-optical switching with the response time on order of 10 fs is demonstrated in a three-dimensional opal polystyrene nonlinear photonic crystal by means precise femtosecond pump-probe technique. The realized shift band gap under external optical pumping 8 Ti:sapphire pulse laser peak pump power 20.6 GW/cm2. good performance attributed to very strong and fast Kerr material.

Abstract Photoconductive terahertz emitters have proven to be crucial devices for generating radiation, which has broad applications in imaging, broadband spectroscopy, nonlinear spectroscopy etc. Traditional photoconductive are typically stimulated by 800 nm lasers, however, face challenges such as integration and cost. A noteworthy alternative is the use of driven 1550 lasers. This approach establishes a connection between technology communication technology, offering benefits lower cost...

Terahertz noise sources have important application prospects in figure measurements. In this paper, a 0.4 THz broadband terahertz source based on photoconductive antenna is proposed. As demonstration of feasibility, generated by mixing three beams Gaussian-shaped incoherent light. The resulting excess ratio (ENR) across different frequency bands as follows: 20.9 dB, with flatness ±7.9 dB the 75~110 GHz range; 19.3 ±6.2 110~170 20.6 ±4.8 170~260 and 18.7 ±4.3 260~400 range. These results...

We propose a new scheme on unidirectional surface plasmonpolariton (SPP) excitation with the following advantages: ultracompact size, working at arbitrary incidence angle and over wide spectrum.The proposed structure utilizes partially filled metallic slot dielectric to realize SPP via direct field manipulation.We theoretically numerically show that ratio of 93% can be achieved by 50 nm slot.The keeps its functional capability incident angles from -80° 80°, has broadband spectrum more than 70 nm.

Due to the abilities of manipulating wavefront light with well-controlled amplitude, and phase polarization, optical metasurfaces are very suitable for holography, enabling applications multiple functionalities high data capacity. Here, we demonstrate encoding two- three-dimensional full-color holographic images by an ultrathin metasurface hologram whose unit cells subwavelength nanoslits spatially varying orientations. We further show that it is possible achieve multiplexing such kind...

We present a versatile technique based on nano-imprint lithography to fabricate high-quality semiconductor-polymer compound nonlinear photonic crystal (NPC) slabs. The approach allows one infiltrate uniformly polystyrene materials that possess large Kerr nonlinearity and ultrafast response into the cylindrical air holes with diameter of hundred nanometers are perforated in silicon membranes. Both structural characterization via cross-sectional scanning electron microscopy images optical...

We propose a full optimization procedure for designing mantle cloaks enclosing arbitrary objects, using sub-wavelength conformal frequency selective surface (FSS). Rely on the scattering cancellation principle of cloak characterized by an average reactance, personal computer can achieve this design procedure. By combing Bayesian (BO) with electromagnetic solver, we automatically find optimal parameters which nearly cancel from enclosed objects. It is shown that results obtained our method...

Recently, using various intelligent approaches to achieve the efficient inverse design of photonic nanostructures with predefined and appropriate functionalities has attracted considerable attention. We propose a method subwavelength metal-dielectric nanoantennas optimize scattering directionality Bayesian optimization approach. The consisted three gold disks separated by two dielectric layers. geometrical parameters were optimized in an fully automatic process. showed that aid machine...

An alternative metasurface design based on a nonresonant mechanism is proposed and demonstrated. Using the effective medium theory finite element calculation, we show relationship between refractive index geometrical parameters, which potentially can be used for tuning wavelength wavefront of surface plasmon polariton (SPP). Experimental studies our were conducted by near-field scanning optical microscopy subwavelength gold grooves fabricated using focused ion beam (FIB). The metasurfaces...

We design a Kerr-effect sensitive microcavity in hybrid semiconductor nonlinear photonic crystal (PhC) slabs for application all-optical switching. Our new concept cavity is made from infiltrating the air hole array and coating surface of usual PhC with polystyrene, let polystyrene instead occupy center cavity. Optimization by modulating structure parameter yields quality factor Q=1600 shift magnitude δf≈8.4 nm while pumping light intensity 80 GW/cm2. This configuration can help to realize...

High-performance all-optical switching is of paramount importance to realize integrated photonic circuit. Due the ultra-sharp resonance mode, it demonstrated that Fano far superior Lorentz for implementation switching. However, still a difficulty an integratable with faster response and lower energy simultaneously. In this work, we propose double resonances based composed silicon-polymer compound crystal nanobeam (PCN) side-coupled cavity (PCNC). The pump probe wavelengths locate at position...

Nonlinear photonic crystals, whose refractive index distribution can be tuned optically, have been used to demonstrate all-optical switching due a change of the and subsequent shift bandgap edge or defect state resonant frequency. Semiconductor-based is still limited by weak nonlinearity slow response time owing dynamics two-photon-generated free carriers. Here we introduce concept hybrid nonlinear crystals that are made from infiltrating air-hole array coating surface usual semiconductor...

The achievement of ultrafast all-optical switching on chip is a fundamental issue integration. A feasible and promising method for this to combine semiconductor photonic crystals with highly nonlinear polymer materials form the hybrid crystal. In paper we numerically investigate femtosecond dynamic response based effect band gap edge shift in one-dimensional (1D) semiconductor–polymer crystal (NPC) structures. Taking into account Kerr relaxation time simultaneously, introduction can realize...

Dielectric Mie scatterers possessing simultaneously magnetic and electric resonances can be used to tailor scattering utilizing the interference among electromagnetic multipole moments. Cloaking for this type of scatterer is important various applications. However, existing cloaking mechanisms mainly focus on elimination net dipole moments, which have not been generalized a with both responses yet. Herein, we propose experimentally demonstrate an invisible hybrid skin cloak. The mechanism...

Many efforts have been devoted to the design of photonic microcavities and utilization them in optical sensing, imaging, optomechanics, lasing, micromanipulation. Cavities supporting spectrally close multiple resonance modes can favor energy exchange among ambient, enabling nontrivial coherent dynamics that are useful wave manipulation. Coupling between multimode cavities with waveguides is a significant theme for optical, terahertz, microwave signal control, but remains largely unexplored....

Many applications of sensor networks require batteries as the energy source, and hence critically rely on optimisation batteries. But often neglected by networking community, most are non-ideal reservoirs can exhibit battery recovery effect — deliverable in be replenished per se, if left idling for sufficient duration. We made several contributions towards harnessing networks. First, we empirically examine gain runtime due to effect, found this significant duration-dependent. Second, based...

Recently, various high quality factor photonic crystal microcavities have been demonstrated theoretically and experimentally with only one-dimensional periodicity. However, in most cases high-index materials such as silicon were chosen for easily achievable large bandgap elaborate refractive index modulation or taper structure is required reducing radiation loss. Here, we present a design of high-Q multilayer polystyrene slab structures low-index contrast 1.59:1. Microcavities are introduced...

A Kerr-effect sensitive microcavity device based on the two-dimensional pillar-array hybrid nonlinear photonic crystal slab has been designed for all-optical switching. The cavity is made from infiltrating void space of semiconductor with polystyrene. structure parameters have optimized by numerical simulations three-dimensioanl finite-difference time-domain method. It found that resonant wavelength can shift 15 nm under pump light an intensity 80  GW/cm2, which far larger...

We propose a multiscale spoof-insulator-spoof (SIS) waveguide by introducing periodic geometry modulation in the wavelength scale to SIS made of perfect electric conductor. The MSIS consists multiple subcells. dispersion relationship fundamental guided mode spoof surface plasmon polaritons (SSPPs) is studied analytically within small gap approximation. It shown that possesses microwave band (MBG) due Bragg scattering. "gap maps" design parameter space are provided. demonstrate subcells can...