Journal of Optoelectronical Nanostructures
Volume:6 Issue: 4, Autumn 2021

To the best of our knowledge, it is for the first time thatTERS system in near-infrared (NIR) spectrum isreporting. The current study proposed a most favorableatomic force microscopy (AFM) tip based on anincorporated optimal grating structure close to the tipapex. The optimized M2 factor and the best spatialresolution are obtained as 5.9× 109 and 8.5 nmrespectively in the NIR range of radiation light. Theresults show that the optimized grating can effectivelyincrease the amount of intensity of electric field andimprove spatial resolution within the nanoslit between theAFM tip and substrate. The detection sensitivity ofmaterials can be done by our proposed AFM-TERSsystem. The difference between the maximumenhancement factors that are correlated to several undertest sample molecules show the selectivity potential ofthe proposed AFM-TERS system in material detectiontopic.

Wide bandwidth and high data transfer rates are essentialadvantages of optical telecommunication networks. Fullexploitation of the benefits of optical communicationsrequires a fully optical network. All-optical circuits areone of the main alternatives to eliminate the limits ofelectronic circuits and provide high-speed processingsystems. This study aims to design an Majority Gate basedon the Nonlinear Kerr Effect. The proposed structureincludes a directional coupler with nonlinear rods. In theproposed structure, a nonlinear directional coupler is usedto transmit the phase of the input signal. Also, inputconnections are optimized to prevent the return of lightalong the structure. To evaluate the operation of theproposed structures, PWE and FDTD methods are used.The effect of some parameters variation on the outputpower has been investigated, proving the robustness of thisdesigned structure of Majority gate against processvariation. In this simulation, the proposed structures'switching power is 3 W and the bit rate is Tbits/s.

This paper aims at proposing a new designbased on the refractive index using 2D photonic crystals(PCs) for diagnosing basal cell carcinoma (BCC). Thisproject consists of a square array of GaAs rods in SiO2.This structure has two inlet and outlet waveguides and amicro-cavity. Waveguides are employed to couple lightto the cavity, and the cavity to inject analyte into it. SomePC rods were used to separate the cavity from the inletand outlet waveguides. The results show that by injectingan analyte into the cavity and changing its refractiveindex, a shift occurs in the resonance wavelength of thetransmission spectrum. The high sensitivity coefficientobtained for this sensor is 730 nm/RIU and its highFigure of Merit (FoM) is 11428. For numerical analysisof the transmission spectrum, Q-factor, and sensorsensitivity, the finite-difference time-domain (FDTD)method was used. High simplicity, sensitivity, FoM makeit suitable for biosensing applications.

Thin layer of titanium dioxide has been deposited on a glass sheet using RF magnetron sputtering under different preparation conditions. Phase, lattice parameters, optical features and morphology were investigated under different laboratory conditions in different thicknesses by using XRD, spectrophotometry and atomic force microscopic (AFM), within the visible spectrum range. Also, the lattice structure, in most cases, is tetragonal or a combination of tetragonal and orthorhombic. The band gap energy for each layer was measured using Tauc’s Plot. It was observed that the edge of absorption is reduced following an increase in thickness except for a thickness of 75 nm. By increasing the pressure, the band gap energy of the layers or the edge of absorption increases except for 0.04 mbar. By increasing the power, the band gap energy of the layers will change resulting in an increasing-decreasing trend in the edge of absorption, which can be the outcome of changes in the lattice formation. Nevertheless, it is obvious that the band gap energy, phase, lattice parameter and morphology is totally dependent on the laboratory conditions of making layers.

Single photon sources are the basis of quantumcomputing. An optical system including a quantum dot(QD) within the micro-pillar cavity can be a candidate forhigh quality single photon source. Here, the vacuum Rabisplitting (VRS) of this optical system for differentsituations was studied. The coupling constant thresholdof this Single photon source to start VRS, was calculatedfor each of these situations. Then, given that the Purcellfactor threshold for using single photon source pulses inlinear optics quantum computing is , Purcellfactor behavior of this single photon source including aQD with FWHM of 5μeV, was studied. The resultsshowed that to use the single photon pulses of this systemin quantum computation ( ), the FWHM of micropillarcavity must be less than 100μeV. Also, for cavitieswith normal FWHM range, if coupling constant is greaterthan 50μeV, then and therefore its singlephotons can be used for quantum computing.

We study the supercontinuum generation in a nonlinearsilica single layer plasmonic waveguide. A major part ofspectral broadening is related to soliton dynamics when anultra-short pulse is launched in waveguide with anomalousGVD. Production of supercontinuum with 10th, 15th and30th, orders bright solitons by considering all the nonlineareffects and dispersions i.e., inter-pulse Raman scattering,self-steepening, self-phase modulation, cross phasemodulation, which indicates the existence of asupercontinuum propagation about 20 times broadeningthan initial width of input spectrum.Also, we consider the absorption effect of plasmonicwaveguide by calculating propagation length frompropagation constant. The propagation length of plasmonicis compared with the waveguide length and nonlinearlength. At wavelength 1.22μm, the propagation length isobtained in the order of waveguide length which means onecan consider the effect of absorption cannot alter theresults. The nonlinear plasmonic waveguides are suitablefor integrated photonics because of subwavelengthconfinement of plasmonic waveguides.