Radiative and nonradiative recombination law in lightly doped InGaAsP lasers

We analyse data relating to radiative and nonradiative recombination in a 1.3 ?m InGaAsP laser operating below threshold. The results show that with a lightly doped active region the radiative recombination coefficient decreases with increasing carrier concentration in accordance with previous theoretical results. Further, they indicate that the Auger nonradiative recombination is relatively small.     

Polarization mode dispersion in short fiber lengths

We perform Monte Carlo simulations of the statistical properties of the differential group delay for fiber lengths less than and of the order of the birefringence correlation length. We find that the manner in which quantities related to the polarization mode dispersion evolve along the fiber depends significantly on the model assumed for the form of the birefringence.     

Fabrication tolerance of asymmetric silicon-on-insulator polarization rotators

We investigate the fabrication tolerance of novel slanted-angle silicon-on-insulator polarization rotators with asymmetric external waveguiding regions. We also minimize the input and output coupling loss between the polarization rotator and the rib waveguides through a lateral shift in the relative waveguide positions.     

Improved multicanonical algorithms

We introduce several easily programmed techniques that enhance the accuracy of multicanonical sampling. With minor modifications to the standard technique, our methods achieve equivalent or enhanced accuracy compared with existing, often far more complex, algorithmic refinements. Despite their simple formulation, these procedures have been previously overlooked because of the low cost of additional realizations in numerical calculations. When applied in the context of our recently introduced experimental multicanonical measurements, however, significant time savings can result.     

New formulations of the matrix beam propagation method: applicationto rib waveguides

A technique for the spectral analysis of strongly guided optical waveguiding media based on a variant of the recently introduced matrix beam propagation algorithm is discussed. In particular, it is shown that the lowest order modes of rib waveguides can be generated with a simple computer program using this method. The results are also obtained using a standard finite-element procedure. The relative efficiency of the two methods is considered. The propagating electric field and differential losses in a Y junction fabricated from rib waveguides are also evaluated     

Differential group delay prediction in optical fiber links

We simulate the time evolution of differential group delay (DGD) in a fiber link in the hinge model with time series forecasting procedures, in particular, autoregressive (AR) models with Kalman filter, pattern imitation, and a Taylor expansion. In these studies, the furthest prediction horizon was attained with the AR accompanied by the Kalman filter procedure. We further discuss the influence of measurement noise on the prediction horizon. We also apply these methods to the measured DGD on 40 Gb/s fiber links and discuss the results.     

Biased multicanonical sampling

A modified multicanonical method is introduced that improves computational accuracy within selected regions of system parameters. The numerical accuracy of the method is established by evaluating the joint distribution function of first- and second-order polarization-mode dispersion in weakly birefringent optical fibers.     

Analytic studies of absorbing and impedance-matched boundary layers

We provide accurate formulas for the reflection coefficient associated with absorbing and impedance-matched boundary layers as well as from regions with nonequidistant grid point spacings in Schrodinger-like differential equations. We further discuss the optimization of the layer profile.     

Comparative evaluation of a novel series approximation for electromagnetic fields at dielectric corners with boundary element method applications

This paper presents a series solution for the longitudinal electromagnetic fields at arbitrary dielectric corners. We apply versions of the method that are up to sixth-order accurate to our recently proposed full vector boundary element method (BEM) mode solver. Our results indicate that our previous formulation models corner fields with high precision.