Abstract
In this letter, we report the infrared optical properties of a novel silica aerogel substrate. The properties were measured at room temperature using spectroscopic ellipsometry in the wavelength range from 8 to 14 pm. The measurements gave a refractive index in the range 1.01 to 1.09 and an extinction coefficient variation between approximately 0.0096 to 0.0104. These results confirm the effectiveness of using silica aerogel as a substrate for antenna-coupled microbolometer detectors.