Novel techniques for quasi three-dimensional nanofabrication of Transformation Optics devices

Current nanofabrication is almost exclusively limited to top-down, two-dimensional techniques. As technology moves more deeply into the nano-scale regime, fabrication of new devices with quasi three-dimensional geometries shows great potential. One excellent example of an emerging field that requires this type of non-conformal 3D fabrication technique is the field of Transformation Optics. This field involves transforming and manipulating the optical space through which light propagates. Arbitrarily manipulating the optical space requires advanced fabrication techniques, which are not possible with current two-dimensional fabrication technologies. One step toward quasi three-dimensional nanofabrication involves employing angled deposition allowing new growth mechanisms, and enabling a new realm of quasi three-dimensional fabrication.^ Transformation optics also has potential for having a huge impact on one of the most fundamental and impactful aspects of optics - the capability of fully controlling and manipulating the phase of light. For this purpose, dielectric metamaterial arrays can be fabricated, altering the phase of light transmitted through the structures, while maintaining a high transmittance (low reflection). By fabricating these structures with a high-index material (such as silicon), a large gradient in phase can be implemented by adjusting the material\u27s effective filling fraction. Using these dielectric metamaterial arrays, anomalous refraction and focusing is demonstrated in films with thicknesses less than one wavelength