First On-Chip Metamaterial with Refractive Index of Zero
Image credit: Peter Allen, Harvard SEAS
Metamaterials with a refractive index of zero exhibit physical properties such as infinite phase velocity and wavelength. However, there is no way to implement these materials on a photonic chip, restricting the investigation and application of zero-index phenomena to simple shapes and small scales.
Researchers in Eric Mazur's lab designed and fabricated an on-chip integrated metamaterial with a refractive index of zero in the optical regime. Light refracts perpendicular to the facets of a prism made of this metamaterial, directly demonstrating that the index of refraction is zero. The metamaterial consists of low-aspect-ratio silicon pillar arrays embedded in a polymer matrix and clad by gold films. This structure can be fabricated using standard planar processes over a large area in arbitrary shapes and can efficiently couple to photonic integrated circuits and other optical elements. This novel on-chip metamaterial platform opens the door to exploring the physics of zero index and its applications in integrated optics.
Read the SEAS press release and the original article: Y. Li, S. Kita, P. Muñoz, O. Reshef, D.I. Vulis, M. Yin, M. Lončar & Eric Mazur, "On-Chip Zero-Iindex Metamaterials," Nature Photonics 19 October 2015 | doi:10.1038/nphoton.2015.198