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We report the behavior of spatial optical solitons propagating through inhomogeneous waveguides with Gaussian, single triangular, and double-triangular refractive index profiles. In a given Gaussian profile, as the soliton amplitude decreases below a certain value, its behavior deviates from that of a particlelike soliton. Dependence of the swing period of a spatial soliton in a single triangular index profile on its amplitude, [eta], is less significant than that in a Gaussian profile. We also report the interacting behavior of two solitons propagating simultaneously through a waveguide with a double-triangular index profile. Furthermore, we present the effects of the solitons' initial phase factors and amplitude on their behavior. OCIS codes: 130.7290, 190.3270, 190.4360, 190.6135.

Due to the pronounced scientific and technical attention paid to the mid-infrared spectral region, we focus on ultra-wide mid-infrared supercontinuum generation in As40Se60 chalcogenide SIF and PCF—step index and photonic crystal fibers—using a symmetrized split step Fourier method (S-SSFM). Simulations reveal, in response to launching 100 fs input pulses of 50 kW peak powers, with near zero dispersion wavelengths centered about \lambda 0 = 8.5 μm, into 50-mm long As40Se60 SIF and solid core PCF, 8.5 and 11-μm supercontinua can be achieved, respectively. Moreover, numerical results also show, when ultra-short pulses of center wavelengths \lambda 0 = 12 μm are launched into those SIF and PCF, ripple free spectra as wide as 10 and 13 μm can be attained, respectively. These spectra are useful for safe spectroscopic medical imaging diagnosis such as early cancer diagnostics, and other spectroscopic applications such as gas sensing and food quality control. [ABSTRACT FROM PUBLISHER]

Based on existing model for dielectric function of an effective medium in response to H-polarized (TE) mode, we have developed a new comprehensive analytic model for dielectric function (\varepsilonTE) of an individual multi-wall carbon nanotube (MWCNT) that satisfies the Kramers-Kronig relation. Taking advantage of this model and utilizing the 2D Finite difference time domain (FDTD) method we have calculated the photonic response of \beta-aligned ordered arrays of MWCNTs to TE mode, over the frequency range of 0.5–10 PHz. Dependence of the photonic response on the lattice periodicity, CNTs' inner and outer radii, and the lattice orientation with respect to the propagation direction have been studied, systematically. Furthermore, using an existing model for \varepsilonTM, similar dependencies for the photonic response to E-polarized (TM) mode, have also been obtained. The numerical results can be used in designing photonic devices applicable in the range of near to deep UV, such as filtering, switching, superlensing, plasmonic antennas, and optical sensors. [ABSTRACT FROM PUBLISHER]

The authors propose two 1 x N all optical switches by taking the advantage of the accelerating behaviour of a spatial soliton in a Mach-Zehnder waveguide and the soliton's oscillating behaviour while propagating inside the nonlinear waveguide. The proposed switches consist of asymmetric and symmetric Mach-Zehnder waveguides followed by a homogenous Kerr medium, which is terminated by N parallel trapezoidal waveguides. In these switches, the signal is dropped from one of the desired output channels by changing the input pulse of wavelength or power. The numerical results confirm the switching application and show that the proposed lxJV switches can be used for wide ranges of wavelength and power, which are suitable for optical communication networks and optical data processing systems. [ABSTRACT FROM AUTHOR]

In this paper , an inductor-less , high frequency tuning range and low power CMOS voltage controlled oscillator (VCO) is presented . The VCO can be implemented in 0.18 μm CMOS , with 1.8 V supply voltage . By using a novel structure , a high frequency tuning range , low phase noise and low power consumption VCO , is obtained . In order to increase the frequency tuning range , an active inductor is used . In addition , deep triode region transistors are employed to enhance the swing of the output voltage . By using the results of simulation with HSPISE software , the tuning range , phase noise and power consumption are 5.49-9.6 GHz , - 146 dBc/Hz and 5.99 mW , respectively . [ABSTRACT FROM AUTHOR]