Photonic crystals

Photonic crystals are periodic nanoscale structures built from materials with different refractive indices, which control light propagation in a way analogous to how a crystal lattice controls the motion of electrons in a semiconductor.

How do photonic crystals work?

The periodicity of the structure creates a so-called photonic bandgap — a range of light frequencies that cannot propagate inside the crystal in any direction. Introducing a defect into the periodicity lets you create precisely controlled light-propagation paths or high-quality-factor resonant microcavities.

Applications

Photonic crystals are used in designing waveguides with ultra-small bend radii, high-performance photonic crystal fibers, low-threshold lasers, and very narrowband optical filters.

Related terms

FDTD

Plasmonics

Optical waveguide