Optical properties of popular dielectric substrate materials in a wide spectral range from far-infrared to ultraviolet

Abstract

We investigated the optical properties of 13 different dielectric materials (slide glass, quartz, Al₂O₃ (c-cut), DyScO₃ (110), KTaO₃ (001), LaAlO₃ (001), (LaAlO₃)_0.3-(Sr₂AlTaO₆)_0.7 (001) (LSAT), MgF₂ (100), MgO (100), SiC, SrTiO₃ (001), TbScO₃ (110), and TiO₂). The single-bounce reflectance spectra of the bulk samples were measured using Fourier transform infrared (FTIR) and monochromatic spectrometers across a wide spectral range, from far infrared to ultraviolet (80–50,000 cm⁻¹). Using the Kramers–Kronig analysis, we obtained the optical conductivity and dielectric function of the dielectric materials from their measured reflectance spectra. Moreover, we measured the transmittance spectra of the materials to obtain their bandgaps. We fitted the measured reflectance spectra using the Lorentz model to obtain phononic structures. Each dielectric material exhibits unique phononic structures and optical bandgaps, associated with the composition and crystal structure of the material. The observed optical properties of these dielectric materials provide valuable information for the optical analysis of thin films grown on them.