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In this paper, a rigorous two‐dimensional full‐vectorial finite difference time domain (2D‐FVFDTD) method is developed for an efficient analysis of nonradiative dielectric waveguide (NRD guide) devices with three‐dimensional structure. A Convolutional perfectly matched layer is employed as an absorbing boundary condition. Furthermore, we have established a rigorous formulation for estimating the modal power of each LSM01 ${\text{LSM}}_{01}$ and LSE01 ${\text{LSE}}_{01}$ mode. We confirmed the validity of the proposed method through the analysis of NRD crossing and T‐branch guide devices. Excellent accuracy is achieved by the cross comparison of 2D‐FVFDTD results with recently developed two‐dimensional full vectorial finite element method. [ABSTRACT FROM AUTHOR]

This paper studies on polarization beam splitter (PBS) in high-index-contrast waveguides based on sinusoidally driven directional coupler (SDDC), and offers new insights to realize compact and low-loss PBS with high fabrication tolerance. The PBS based on SDDC has advantage that power shift to an adjacent waveguide can be suppressed or totally banned by satisfying coherent destruction of tunneling (CDT) condition. However, in practical implementation, the PBS based on SDDC has trade-off relation between cross-talk of TE-like wave and loss of TM-like one. This paper investigates characteristics of the SDDC numerically, and shows possibility that cross-talk and loss can be suppressed, and small footprint can be achieved by position shift of DC-gap maintaining high fabrication tolerance. [ABSTRACT FROM AUTHOR]

A holey fiber having a core with an elliptical-hole lattice structure, which is referred to as an elliptical-hole core circular-hole holey fiber (EC-CHF), can be easily designed as a single-polarization fiber by using the fundamental space-filling modes of the core and cladding lattices. However, because the guided mode in an EC-CHF has a polarization that arises from the large geometric anisotropy of the core lattice, the influence of the bending direction on the bending loss is a crucial issue for the practical implementation of EC-CHFs. Here, the bending losses of an EC-CHF bent in arbitrary angular orientations with respect to the core cross section are calculated numerically using the equivalent anisotropic step-index circular fiber model for a real EC-CHF, and the influence of the bending direction of the fiber on the bending loss is discussed. OCIS codes: 060.2310, 060.2400, 060.2420.

A full-wave finite-element method with hybrid edge/ nodal elements is, for the first time, applied to investigating the frequency dispersion of microwave propagation characteristics of broad-band traveling-wave (TW) optical modulators using planar electrode configurations. In order to produce a two-step analysis of electrooptic modulation of optical waveguides, the microwave electrode solver is linked to the optical waveguide solver. Numerical results are shown for an ultrabroad-band TW LiNb[O.sub.3] Mach-Zehnder optical modulator with a ridge structure, and the necessity of using the full-wave solver is verified by comparing the calculated 3-dB bandwidth and half-wavelength voltage with the experimental data. Index Terms - Coplanar waveguide, finite-element method, full-wave analysis, microwave photonic device, traveling-wave optical modulator.

The perfectly matched layer boundary condition is incorporated into the beam propagation method based on a finite element scheme. To show the validity and usefulness of this approach, numerical results are shown for a double U-bend and linear tapers with different index contrast and opening angle. Index terms - beam propagation method, finite element method, perfectly matched layer, wide-angle beam propagation, optical waveguide analysis

A wide-angle finite element beam propagation method using a Pade approximant operator is described for strongly guiding and longitudinally varying optical waveguides. In order to show the validity and robustness of this approach, numerical results are compared with those of other beam propagation algorithms.