2015 was 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 raised special attention for major topics and key technologies in the field of optics and photonics. Advanced Optical Materials contributed to this goal by publishing a special series of outstanding review articles.
3D printing is nowadays used routinely in industry mainly for rapid prototyping. However, industrial 3D printers do not reach down to the micrometer scale and are typically limited to a layer-by-layer fabrication scheme. μ-printing utilizes the polymerization of a photosensitive material via non-linear-optical processes, which only occur at the very focus of a laser beam. In this way almost any 3D structure can be fabricated with submicrometer precision and feature size. This technology enabled the fabrication of 3D photonic samples with and without functional elements, chiral photonic crystals, photonic metamaterials and quasicrystals to name a few.
In their progress report Georg von Freymann and co-workers (University of Kaiserslautern, Germany) summarize the tremendous technological development of 3D μ-printing during the last five years and give an overview of some rapidly growing research fields enabled by this technology. The technology development goes towards smaller features and increased resolution on one hand, and larger printing volumes and increasing fabrication speed on the other hand. These newly available three-dimensional structures provide researchers in different fields, like photonics, metamaterials and biology, with new insights and novel research directions. Novel directions and future challenges of this technology are also discussed in their comprehensive review article.
The full series can be found at www.advopticalmat.de/IYL. All articles are published in Advanced Optical Materials and featured in this virtual issue.