Two-photon cavity solitons in active optical media

We show that broad-area cascade lasers with no absorbing intracavity elements support the spontaneous formation of two-dimensional bright localized structures in a dark background. These cavity solitons consist of islands of two-photon emission embedded in a background of single-photon emission. We discuss the mechanisms through which these structures are formed and interact, along with their properties and stability.     

Thermal analysis of agricultural residues with application to production fuels

An important application of agricultural residues is as fuels for combustion processes. This paper shows how thermal analysis can be used for characterization of different kinds of cereals with a view to increasing efficiency in combustion processes. Results are in good agreement with those derived from standard ASTM methods.     

Conformal coverage for two-dimensional arrays of microcavites with quasi-three dimensional confinement by distributed Bragg reflectors

Different from conventional three-dimensional confined microcavity fabrication method in which micropillar microcavities were obtained through the etching of planar semicoductor microcavities, we adopted the conformal coverage to fabricate two-dimensional arrays of quasi three-dimensional confined optical microcavities providing both vertical and lateral optical confinement by the distributed Bragg reflectors (DBRs). Our microcavity samples were directly deposited on the patterned substrates with two-dimensional arrays of air holes. The SEM and cross-section TEM images show that the periodicity of the patterned substrate was still kept after deposition while the growth of DBRs along the sidewalls occurred simultaneously, which provided the transverse optical confinement. In order to probe the optical modes of this kind of microcavities, room temperature photoluminescence signals from prepared microcavities were detected. Three resonant modes were presented and exhibited obvious angular dependence. We attributed these phenomena to quantization of the in-plane wave vector components confined by lateral DBRs.     

Diagrams in Categories of Partial Linear Spaces of Order Two

In this note we define, using a universal property, the concept of diagram for a space in categories of not necessarily finite partial linear spaces of order two and prove that in the category of symplectic-type spaces all spaces have diagrams.     

Constructing integrable systems of semitoric type

Let (M, ω) be a connected, symplectic 4-manifold. A semitoric integrable system on (M, ω) essentially consists of a pair of independent, real-valued, smooth functions J and H on M, for which J generates a Hamiltonian circle action under which H is invariant. In this paper we give a general method to construct, starting from a collection of five ingredients, a symplectic 4-manifold equipped a semitoric integrable system. Then we show that every semitoric integrable system on a symplectic 4-manifold is obtained in this fashion. In conjunction with the uniqueness theorem proved recently by the authors, this gives a classification of semitoric integrable systems on 4-manifolds, in terms of five invariants.     

Analysis of a Simplified Model of Rigid Structure Floating in a Viscous Fluid

Journal of Nonlinear Science - We study the interaction of surface water waves with a floating solid constraint to move only in the vertical direction. The first novelty we bring in is that we...     

On the Lie symmetry analysis,analytic series solutions,and conservation laws of the time fractional Belousov–Zhabotinskii system

Nonlinear Dynamics - In this study, a reaction mechanism proposed by Belousov and Zhabotinskii, which corresponds to many physical phenomena, from the complex wave behavior of the heart and various...