Proposal for enhancing the transmission efficiency of photonic crystal 60° waveguide bends by means of optofluidic infiltration.

We are proposing a procedure to enhance the transmission efficiency of 60° photonic crystal (PhC) waveguide bends by means of selective optofluidic infiltration of an air hole, which is created as a point defect at the center of the conventional 60° PhC bend. Numerical studies demonstrate that by varying the defect radius and indices of optical fluids, one may enhance the bend transmission level and tune its 3 dB bandwidth over a substantial range of 88-138 nm. In order to perform the numerical simulations, we have used two-dimensional (2D) finite difference time domain plane wave method, keeping in mind that the spectral features obtained by these 2D calculations are about 15% redshifted from those of real three-dimensional structures.

Compact all-optical tunable filter with embedded preamplifier and channel selector based on cross-Raman scattering in an Si nanowire waveguide.

We propose a novel and compact all-optical tunable filter with embedded preamplifier and channel selector. This filter is based on cross-Raman scattering (XRS) in a silicon nanowire waveguide, suitable for multichannel optical communications. Tuning is performed by means of tuning the pump center wavelength. With this tuning approach the separation between the pump wavelength and that of the desired channel should equal the Raman shift in Si. Spanning over 40 optical communication channels following the ITU-T G.694.1 standard (100 GHz grid), our simulation results have demonstrated an excellent channel selectivity and tunabilty for the proposed all-optical filter. The XRS process in Si nanowire has amplified the desired channel by about 11.5+/-0.38 dB, while the suppression ratios for the first and the second neighboring channels are about 28+/-0.25 and 33.6+/-0.31 dB, respectively.

Swing effect of spatial solitons propagating through Gaussian and triangular waveguides.

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.