Skip to main content

The Optical Constants Database

The Optical Constants database (OCdb) is a new data repository developed to provide published, peer-reviewed, optical constants of organic refractory materials and ices relevant to planetary and astrophysical environments to the scientific community for the analysis and interpretation of observational data.

Optical constants are the real and imaginary parts of the complex refractive index, n + ik, of a material, which describe how a material interacts with incident light (transmission, reflection, refraction, absorption, scattering).

They are fundamental input parameters for models (e.g. radiative transfer, atmospheric, and reflectance spectral models) that are used to interpret observational data. As such, they support strategic research activities recommended by the "Origins, Worlds and Life" Planetary Science and Astrobiology Decadal Survey 2023-2032 such as "measuring the composition of hazes and aerosols in the atmosphere and on the surface [of planetary bodies]", "determining the distribution, nature and abundance of clouds and the composition [] of the droplets comprising them and cloud condensation nuclei around which they form", "[constraining] the compositions of planetary surfaces from remote sensing data" and "[improving] the characterization of diverse ices, and the mineral and organic products of water-rock interaction that are fingerprints of habitability"."

The goal of the Optical Constants database is to centralize published optical constants data to facilitate their access by the community. We therefore encourage laboratories generating optical constants to contribute their data in order to increase their visibility and availability.