In this paper a new optical channel drop filter (CDF) based on two dimensional (2-D) photonic crystals (PhC) with hexagonal shaped structure is proposed and numerically demonstrated by using the finite-difference-time-domain (FDTD) and plane-wave-expansion (PWE) techniques. Photonic crystals (PhCs) are artificial dielectric nanostructure materials in which a periodic modulation of the material ...

We characterize the self-parallel (mitered) offsets of a general nonconvex polytope Q in 3-space and give a canonical algorithm that constructs a straight skeleton for Q.

The straight skeleton of a polygon is the geometric graph obtained by tracing the vertices during a mitered offsetting process. It is known that the straight skeleton of a simple polygon is a tree, and one can naturally derive directions on the edges of the tree from the propagation of the shrinking process. In this paper, we ask the reverse question: Given a tree with directed edges, can it be...

We introduce a stable numerical procedure for solving Bohm's equations of motion to compute quantum trajectories in the forward-backward quantum dynamics (FBQD) formulation of zero-temperature time correlation functions. Rather than integrating the differential equations forward in time, our method is based on a series expansion of the quantum trajectory, exploiting Hamilton's law of varying ac...

A quantum field theoretic treatment of inclusive deep–inelastic diffractive scattering is given. The process can be described in the general framework of non–forward scattering processes using the light–cone expansion in the generalized Bjorken region. Evolution equations of the diffractive hadronic matrix elements are derived at the level of the twist– 2 contributions and are compared to those...

We study the computation of the straight skeleton of a planar straight-line graph (PSLG) by means of the triangulation-based wavefront propagation proposed by Aichholzer and Aurenhammer in 1998, and provide both theoretical and practical insights. As our main theoretical contribution we explain the algorithmic extensions and modifications of their algorithm necessary for computing the straight ...