Three-dimensional Photonic Metamaterials: by Direct Laser Writing and Advanced Metallization Techniques

We have utilized a novel fabrication concept, i.e., direct laser writing in combination with advanced metallization techniques to realize three-dimensional photonic metamaterials for optical frequencies. Depending on the type of photoresist, we either used chemical vapor deposition of silver or electroplating of gold. Some of the fabricated structures give rise to bi-anisotropy resulting in a cross-coupling of the electric and magnetic fields of an incident light wave. Additionally, we have presented two unit cell designs which show a negative index of refraction at infrared frequencies.