We present a class of waveguide arrays that is the classical analog of a quantum harmonic oscillator, where the mass and frequency depend on the propagation distance. In these photonic lattices, refractive indices and second-neighbor couplings define the mass and frequency of the analog quantum oscillator, while first-neighbor couplings are a free parameter to adjust the model. The quantum mode...

In this paper, we study the properties of the generalized harmonic numbersHn,k,r(α, β). In particular, by means of the method of coefficients, generating functions and Riordan arrays, we establish some identities involving the numbers Hn,k,r(α, β), Cauchy numbers, generalized Stirling numbers, Genocchi numbers and higher order Bernoulli numbers. Furthermore, we obtain the asymptotic values of s...

Acoustic sensor arrays can be used effectively to provide situational awareness and perimeter defense against small low-flying threat aircraft. Being small and flying low, these aircraft can elude radar detection. However, similar to heavy ground vehicles, these small aircraft emit strong harmonic lines that can be detected and tracked (bearing) at long range. Experimental results from a 16-ele...

We describe families of discrete solitons in quadratic waveguide arrays supported by competing cascaded nonlinear interactions between one fundamental and two second-harmonic modes. We characterize the existence, stability, and excitation dynamics of these solitons and show that their features may resemble those of solitons in saturable media. Our results also demonstrate that a power threshold...

We prepare arrays of gold nanoparticles that include both noncentrosymmetric particles with a second-order nonlinear optical response (active particles) and centrosymmetric particles with no second-order response (passive particles). The plasmon resonances of the active and passive particles are at distinct wavelengths, yet the passive particles modify the electromagnetic modes of the structure...

We predict the existence of spatial-spectral vortex solitons in one-dimensional periodic waveguide arrays with quadratic nonlinear response. In such vortices the energy flow forms a closed loop through the simultaneous effects of phase gradients at the fundamental frequency and second-harmonic fields and the parametric frequency conversion between the spectral components. The linear stability a...

Harmonic pollution of double fed induction generators (DFIGs) has become a vital concern for its undesirable effects on power quality issues of wind generation systems and grid-connected system, and the double pulse width modulation (PWM)converter is one of the main harmonic sources in DFIGs. Thus the harmonic analysis of the converter in DFIGs is a necessary step to evaluate their harmonic pol...

In this study, Salmonella Typhimurium bacteria removal from polluted water has been investigated using multiwall carbon nanotubes arrays. Experimental results reveal that the contact time, the bacterial concentration and the weight of multiwall carbon nanotubes arrays have positive significant effects on the bacteria removal efficiency. Increasing the contact time and the weight of multiwall ca...

We report on the design and experimental demonstration of array-enhanced nanoantennas for polarization-controlled multispectral nanofocusing in the near-IR spectral range. We design plasmonic double bow-tie nanoantennas-coupled to multiple-periodic nanoparticle arrays to harvest radiation of designed wavelengths from a large spatial area and to focus it into a targeted nanoscale region. Near-fi...