Guan Chunying

Photonic Crystal Polarizing and Non-Polarizing Beam Splitters

A polarizing beam splitter (PBS) and a non-polarizing beam splitter (NPBS) based on a photonic crystal (PC) directional coupler are demonstrated. The photonic crystal directional coupler consists of a hexagonal lattice of dielectric pillars in air and has a complete photonic band gap. The photonic band structure and the band gap map are calculated using the plane wave expansion (PWE) method. The splitting properties of the splitter are investigated numerically using the finite difference time domain (FDTD) method.

Photonic band gap structures in 2D tunable magnetic photonic crystals

The photonic band structures in 2D tunable hexagonal magnetic photonic crystals were investigated on the basis of plane wave expansion method. It was found that the photonic band gaps tended to exist in the magnetic photonic crystals, and magnetic permeability affected the photonic band gaps strongly. The width of two absolute band gaps was reduced gradually, then they vanished when magnetic permeability increased from 1.0 to 5.0 in photonic crystals with magnetic scatterers surrounded by air. However, as magnetic permeability continued to increase, an absolute band gap could appear in the lower frequency, and gap-mid-gap ratio increased and the optimal filling ratio changed lightly. Analogously, an absolute band gap also appeared in the lower frequency in photonic crystals with air scatterers surrounded by magnetic material. Further, the results revealed that the characteristic in photonic crystals with dielectric scatterers surrounded by magnetic material is similar to that in photonic crystals with magnetic scatterers surrounded by air.

Electromagnetic Characterized Parameters of Negative Refractive Index Metamaterial

Two kinds of H-patterned unit structures are analyzed based on the equivalent homogeneous medium theory, the electromagnetic characterized parameters representing the effect of negative refractive index (NRI) are obtained, including wave impedance, refractive index, relative permittivity and relative permeability. Draw a comparison between the obtained parameters above, we find that the transmissivity and the frequency range with NRI are two aspects to be simultaneously considered in the process of NRI metamaterials constructing.