Various grating configurations are introduced to develop structures for the mode conversion of an ultrafast, ultrawide-bandwidth optical pulse propagating in a layered dielectric waveguide. Introducing a new technique for efficient, real-time mode extraction, we examine these schemes with a full-wave, vector, finite difference time domain (FDTD) Maxwell equation simulator. The resulting FDTD si...

This paper discusses numerical analysis methods for different geometrical features that have limited interval values for typically used sensor wavelengths. Compared with existing Finite Difference Time Domain (FDTD) methods, the alternating direction implicit (ADI)-FDTD method reduces the number of sub-steps by a factor of two to three, which represents a 33% time savings in each single run. Th...

We theoretically study channel plasmon-polaritons (CPPs) with a geometry similar to that in recent experiments at telecom wavelengths (Bozhevolnyi et al., Nature 440, 508 (2006)). The CPP modal shape, dispersion relation, and losses are simulated using the multiple multipole method and the finite difference time domain technique. It is shown that, with the increase of the wavelength, the fundam...

In this paper, a method is presented for modeling sound propagation in rooms using a signal processing approach. Low order digital filters are designed to match to sound propagation transfer functions calculated from boundary material and air absorption data. The technique is applied to low frequency, finite difference time domain (FDTD) simulation of room acoustics and to real-time image-sourc...

Numerical simulation provides a effective tool for studying both the spatial and temporal nature of acoustic field on 3D or 4D timespace. The paper deals with the description of discrete exterior calculus scheme for the wave equation. This method can be directly implemented on manifold, which is the generation of finite difference time domain method from flat space to curved space.

A competitive neural network (NN) learned by the OLVQ1algorithm has the potential to produce images for land cover mapping.We propose an extended OLVQ1 that adds learning ratios to the originalalgorithm. Applying it to SPOT XS data, we show that higher mappingaccuracies can be obtained compared to those of conventional methods.

In this paper, four channel demultiplexer is designed using two-dimensional photonic crystal for Coarse Wavelength Division Multiplexing applications. The proposed demultiplexer consists of bus wave guide, output wave guide and a cavity. The channel selection is done by having a cavity with unique refractive index. The two dimensional finite difference time domain and plane wave expansion metho...