What does 'photonic crystal' do?

A photonic crystal is a structure that has a periodic arrangement of materials with different refractive indices, which affects the propagation of light within the crystal. The periodicity of the crystal creates a photonic bandgap, similar to how an electronic bandgap works in semiconductors, allowing it to affect certain wavelengths of light. This manipulation of light can be used to control the flow of photons, create waveguides, or enhance certain optical effects such as reflection and transmission at specific wavelengths.

The ability to engineer the structure of photonic crystals opens up numerous applications in opto-electronics, including the development of highly efficient lasers, sensors, and optical filters. By adjusting the dimensions and refractive index of the materials used, scientists can tailor the properties of photonic crystals to optimize their performance for various technologies, making them a key component in advancing optical communication systems and photonic devices.

Other options describe properties or uses that do not accurately represent the fundamental function of a photonic crystal. For instance, while some may reflect light, not all photonic crystals reflect all light, and they primarily serve to control how light propagates rather than simply reflecting it. The storage of light energy and the conversion of electrical signals to optical signals are functions associated with other