RI−Calc: A user friendly software and web server for refractive index calculation

Abstract

The refractive index of an optical medium is essential for studying a variety of physical phenomena. One useful method for determining the refractive index of scalar materials (i.e., materials which are characterized by a scalar dielectric function) is to employ the Kramers−Kronig (K−K) relations. The K−K method is particularly useful in cases where ellipsometric measurements are unavailable, a situation that frequently occurs in many laboratories. Although some packages can perform this calculation, they usually lack a graphical interface and are complex to implement and use. Those deficiencies inhibit their utilization by a plethora of researchers unfamiliar with programming languages. To address the aforementioned gap, we have developed the Refractive Index Calculator (RI−Calc) program that provides an intuitive and user−friendly interface. The RI−Calc program allows users to input the absorption coefficient spectrum and then easily calculate the complex refractive index and the complex relative permittivity of a broad range of thin films, including of molecules, polymers, blends, and perovskites. The program has been thoroughly tested, taking into account the Lorentz oscillator model and experimental data from a materials' refractive index database, demonstrating consistent outcomes. It is compatible with Windows, Unix, and macOS operating systems. You can download the RI−Calc binaries from our GitHub repository or conveniently access the program through our dedicated web server at nanocalc.org.