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.
Abstract
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.