2015 is the International Year of Light, proclaimed by the United Nations to recognize the achievements of light science and its applications, and its contributions to humankind. It will raise special attention for major topics and key technologies in the field of optics and photonics.
There are numerous events and activities around the world and throughout the year. We are proud to be a partner of this initiative with, the aim to create awareness for the importance of light-based technologies. Advanced Optical Materials will contribute to this goal through publishing a special series of outstanding review articles.
Ullrich Steiner (AMI, Fribourg) and co-workers have reviewed the optical properties of two fundamental classes of gyroid structured materials: photonic crystals and metamaterials. These two classes represent gyroids at different length scales: photonic crystals are patterned on the order of the wavelength of light, whereas metamaterials show sub-wavelength structures. The first category exhibits a complete photonic bandgap for a sufficiently large dielectric contrast and shows linear and circular dichroism as well as optical activity. There are natural examples of photonic crystals, like butterfly wings and artificial structures self-assembled from block copolymers which show very similar behavior. The optical properties of gyroid photonic crystals are determined by constructive light interference from the refractive index boundaries in the structure. Metamaterials exhibit optical properties determined by the sub-wavelength structure and the electronic interactions of the used material. The morphology of these structures gives rise to their unique electromagnetic properties, which are generally not found in nature.
This first article of the series can be found at www.advopticalmat.de/IYL. All articles will be published in Advanced Optical Materials and added to this virtual issue over the year.