Low‐refractive‐index materials: A new class of optical thin‐film materials

The refractive index, a most fundamental quantity in optics and optoelectronics, determines many figures of merit of optical components such as reflectors, filters, and resonators. Here we present a new class of optical thin‐film materials that have a very low refractive index. Specular films of high optical quality with refractive indices as low as 1.05 are demonstrated. A single pair DBR incorporating low‐ n material is demonstrated to have enhanced reflectivity, showing the great potential of low‐refractive‐index films for many photonic device applications. (© 2007 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)