Terahertz thin film and refractive index sensing with a metamaterial near-field sensor

We present a metamaterial-based sensor for use at terahertz (THz) frequencies that is suitable for the measurement of the thickness and the refractive index of a dielectric sample material. The sensor is designed to operate in reflection geometry in the frequency range between 1 THz and 1.6 THz. Deep-subwavelength sample thicknesses as small as 1/16000 of the operating wavelength can be resolved as well as refractive index differences of 0.01.