3-D photonic crystals will revolutionize telecommunications

The production of these crystals is based on aqueous dispersions, a key competence of BASF. These dispersions contain polymer spherical particles measuring about 200 nanometers which, when the fluid evaporates, are forming a homogeneous protective film as it is expected with the paints. Depending from the chemical structure of the polymer particles they can also arrange themselves into a regular lattice structure, forming a crystal. The challenge facing the Ludwigshafen scientists is to enlarge the polymer particles contained in the dispersions to 1000 nanometers in such a way, that they all have exactly the same diameter. Using emulsion polymerization, they also apply an additional structure measuring less than 20 nanometers onto the polystyrene particles. The intention is to develop the most stable possible, large volume, three-dimensional crystal into which one of the project partners will then introduce the desired structure, the so called "defects".

Light at certain wavelengths then travels along these defects and even around sharp corners: the photonic crystal then acts as a photoconductor and takes the control over the propagation of light. The resulting structured crystal lattice is used in the further manufacturing process as a template, as the scientists call it. The spaces between the polymer spherical particles in the crystal lattice are filled with silicon. The researchers then "burn" the polymer particles out of the lattice. The result: a stable structure that is a mirror image of the original crystal. Crystals of this type could be used as components for an all-optical routing processor in telecommunications.

Manufacturers of components for telecommunication systems would benefit most from the use of photonic crystals. Since the crystals are smaller than electronic components, equipment would also become increasingly smaller and cheaper – while simultaneously offering improved performance. Components and equipment based on photonic crystals would also be more resistant and less vulnerable to electromagnetic radiation. End users will gain from these advances. In the long term, transmitting information through electrical signals will restrict speed and transmission capacity in telecommunications. The long-term goal is therefore to develop a communications technology based entirely on transmitting information by light waves. The research activities of the "NewTon" project are laying the foundations for this scenario.

For further information about this project, please click on: www.projectnewton.com

BASF is the world’s leading chemical company: The Chemical Company. Its portfolio ranges from chemicals, plastics, performance products, agricultural products and fine chemicals to crude oil and natural gas. As a reliable partner to virtually all industries, BASF’s high-value products and intelligent system solutions help its customers to be more successful. BASF develops new technologies and uses them to meet the challenges of the future and open up additional market opportunities. It combines economic success with environmental protection and social responsibility, thus contributing to a better future. BASF has approximately 95,000 employees and posted sales of €52.6 billion in 2006. Further information on BASF is available on the Internet at www.basf.com.