Fig. 1: Static optical response of the ITO film.
From: Broadband terahertz wave generation from an epsilon-near-zero material
a Schematic of the ENZ sample composed of a 19-nm-thick ITO layer and a 1.1 mm-thick glass substrate. b Real and imaginary parts of the permittivity of the ITO film as a function of wavelength measured via spectroscopic ellipsometry. The ENZ wavelength is marked with a grey dashed line. c Rp/Rs and (Ez,ITO/E0,incident)2 measured (dashed line) and calculated by the transfer matrix method (solid lines) as a function of the wavelength with an incident angle of 40°, where Rp and Rs are the reflectance of p-polarized and s-polarized light, respectively, and Ez,ITO and Ez,incident are the normal components of the electric field in the ITO film and the incident electric field, respectively
