BoX-BOOM · Biomimetic eXtremely-Birefringent Organic Optical Materials and devices

Man-made organic optics relies almost exclusively on amorphous polymers. These cheap, readily processable and highly versatile materials, however, offer a relatively low refractive index, dramatically limiting their ability to generate the high-index contrast necessary for producing scattering layers, photonic crystals and efficient dielectric reflectors. We here propose to establish a new class of novel organic crystalline optical materials and devices by drawing inspiration from the highly birefringent high-index organic molecular crystals nature has to offer, such as those found in dielectric reflectors, photonic crystals and photonic glasses that take part in structural coloration and vision. The crystal structure of these materials, is based on a planar arrangement of hydrogen bonded molecules, which are weakly bound by van-der Waals bonds and weaker hydrogen bonding. The BoX-BOOM project aims to identify new cheap, functional and environmentally benign organic crystalline optical materials inspired by this structural motif, exhibited in biological systems, and to develop ways to grow them in a controllable manner as thin films using surface guided growth. The grown material will in turn be used in new types of optical elements and devices for a broad range of applications such as flat polarization optics, transparent dielectric metamaterials and birefringent volume holograms, all exploiting the high index and extreme birefringence of these materials. Work performed within the BoX-BOOM project will also shed light on the relationship between crystal structure and optical properties of this family of materials, setting the stage for identification of new high-index organic crystalline compounds and a range of applications taking advantage of this new thin-film optical technology.