Iron silicide photonic crystals and light propagation property

We report fabrication of iron silicide photonic crystals and properties of light propagation in two-dimensional (2D) or slab-type photonic crystals (PhC) designed to have their photonic band gaps near 1.55 μm. films were etched by neutral loop discharge reactive ion etching (NLD-RIE) which used a common Si process gas (SF6 + CHF3) system. We propose a new idea to reduce the reflection loss at light incidence. The idea is a characteristic PhC structure (called a conjugated PhC structure) in which inversion photonic patterns are fabricated at the incident interface and they have common photonic band-gap against the wavelength of propagating light. We confirmed large reduction of the reflection loss at the conjugated photonic structure.