Research In Broad Areas Research Articles

A Review of Topological Semimetal Phases in Photonic Artificial Microstructures

In the past few years, the concept of topological matter has inspired considerable research in broad areas of physics. In particular, photonic artificial microstructures like photonic crystals and metamaterials provide a unique platform to investigate topologically non-trivial physics in spin-1 electromagnetic fields. Three-dimensional (3D) topological semimetal band structures, which carry non-trivial topological charges, are fundamental to 3D topological physics. Here, we review recent progress in understanding 3D photonic topological semimetal phases and various approaches for realizing them, especially with photonic crystals or metamaterials. We review topological gapless band structures and topological surface states aroused from the non-trivial bulk topology. Weyl points, 3D Dirac points, nodal lines, and nodal surfaces of different types are discussed. We also demonstrate their application in coupling spin-polarized electromagnetic waves, anomalous reflection, vortex beams generation, bulk transport, and non-Hermitian effects.

Adaptive delivery and handoff management framework for multimedia session mobility

With the increasing use of small portable devices and wireless networks, a trend to support computing on the move has emerged. This trend is referred to as ‘anytime/anywhere computing’ for mobility support. In particular, multimedia service with heterogeneous devices, location-free access and user-context awareness is still a very active and evolving field of research in broad areas. In this paper, a movable multimedia framework, namely UMOST (Ubiquitous Middleware Of Streaming Technology), is proposed for multimedia session mobility.It provides various levels of quality of service management, as well as seamless user-level handoffs using MPEG-21 Digital Item Adaptation (DIA).