Unexpected Photonic Band Gaps in 3D Crystal Structures

Photonic crystals are materials composed of mixed dielectric media that result in the reflection of all electromagnetic waves within a range of wavelengths commensurate with the length scale of the crystal. Such complete photonic band gaps allow for light to be controlled through materials design. Since first theorized in 1987, much effort has been made to define and synthesize photonic crystal structures. In the decades since, many photonic structures have been discovered, often by using naturally occurring crystal structures as templates for design. However, these studies have yet to answer the question: what features of a 3D structure will produce a complete photonic band gap? Here, we present data on over 150,000 potential photonic crystals, and show that complete photonic band gaps are possible for many unexpected structures that have yet to be explored. Our simulations suggest that when designing novel photonic materials, the toolbox of structural templates may be larger and richer than previously thought, widening the field of target crystal structures.