Abstract Nano-meter wave waveguide is a basic element of Nano-meter wave devices, which will be important in nano-technologies, bio-engineering, cell membrane, genetics, and so on. Until now, the nano-meter wave waveguide characteristics have hardly been examined and effective nano-meter wave waveguides have not been developed. We have investigated photonic crystal with a lattice constant of the same order as the wavelength of nano-meter waves.
In the nano-meter wave region, the refractive index of a material becomes smaller than 1, and it has the characteristics depending on the frequency of the incident electromagnetic wave. We have calculated photonic band structures for two-dimensional C and Mo arrays with plane wave expansion method. Although complete bandgaps in these matters do not exist, we have found the existence of local bandgaps.