[Show abstract][Hide abstract] ABSTRACT: Planar photonic integrated circuits based on four-port couplers offer enhanced sophistication and functionality. Each four-port coupler is characterized by sixteen signal coupling coefficients governed by ten energy constraints. The ability to generate the constrained sixteen coupling coefficients is needed in the analysis of the four-port coupler. However, the energy constraint equations are nonlinear and cumbersome to solve directly. We introduce two techniques to reduce these signal coupling coefficients to a set of six free parameters. Hence we can characterize all possible couplers in terms of their sixteen constrained coupling coefficients, or either of two sets of six free parameters. This reduction in parameters has significant ramifications for the design, specification, and empirical characterization of these useful building blocks.
Full-text · Article · Dec 2006 · Journal of the Optical Society of America A
[Show abstract][Hide abstract] ABSTRACT: A signal processing approach to modeling, analyzing, and synthesizing a particular integrated photonic architecture of optical filters with tunable gains is presented. This particular architecture has two-port couplers and current-controlled semiconductor optical amplifiers (SOAs) fabricated on the same substrate. The device architecture forms a new lattice filter structure. Layer-peeling-type algorithms are developed for the analysis and synthesis of the device. The role of the adjustable gains in a lossless or lossy device is considered, and a novel stability algorithm for the filter structure is presented.
No preview · Article · Aug 2006 · Journal of Lightwave Technology
[Show abstract][Hide abstract] ABSTRACT: Propagation of light in optical waveguides and scattering of light at interfaces have been modeled by a class of lattice filter structures. In this paper, the authors propose a recursive algorithm retrieving parameters of each 2-input, 2-output stage of the structure from the coefficients of the given transfer function. A generalized form of the single-input, single-output lattice filter is shown in this paper. The input-output transfer function is defined as the reflection transfer function.
[Show abstract][Hide abstract] ABSTRACT: Take a two stage active Dowling-MacFarlane optical lattice filter with fixed transmission and reflection coefficients and with a stable all pole (in the open left half plane) transfer function in transmission. Consider a second order ordinary differential equation with a stable all pole transfer function and consider a bounded bandlimited input signal. To find an approximate solution to the ODE with zero initial conditions optically, we introduce the following procedure in solving the higher order differential equations using filters with more stages.