Above: Schematic of photonic crystals consisting of cylinders in a honeycomb
lattice viewed from above. Photonic crystals obtained by dividing the nearest
neighboring cylinders into hexagonal clusters, and widening (left) or narrowing (right)
the separation between hexagonal clusters from the original honeycomb lattice (middle),
while keeping the shape and size of hexagons. Below: Relationship between the wave number
and frequency of the photonic crystal in each case. Here, a0 denotes the distance between the
hexagonal clusters as measured from their center, and R denotes the length
of one side of the hexagon.
Achievable Even by Silicone Alone; Developments of New Functions through Integration with Semiconductor Electronics
(September 18, 2015) NIMS MANA researchers elucidated a new principle whereby electromagnetic waves including light propagate on the surface of a photonic crystal without being scattered.
1. Xiao Hu, Principal Investigator of the International Center for Materials Nanoarchitectonics (MANA), National Institute for Materials Science (NIMS), and Long-Hua Wu, NIMS Junior Researcher, elucidated a new principle whereby electromagnetic waves including light propagate on the surface in a photonic crystal without being scattered. By merely slightly adjusting positions of insulator or semiconductor cylinders (nanorods) in a honeycomb lattice, electromagnetic waves can propagate without being scattered even at corners of crystal or by defects. Since this property can be achieved even by a semiconductor, such as silicone, alone, developments of new functions are expected via integrating information processing functions achieved by the well-established semiconductor electronics and the excellent propagation property of electromagnetic waves.
2. In recent years, active studies have been conducted on materials with topological properties where unique properties appear on surfaces of materials. Suppressions of scattering of light by defects in conventional photonic crystals is also expected in topological photonic states. However, special materials were required to create topological photonic crystals.