Precise air wavelength-vacuum wavenumber conversion

Abstract

A fast converging iterative algorithm based on the Edlén1 refractive index formula has been developed. It uses corrections from the virial equation of state for air-water vapor mixtures2,3 and the recently revised refractive index of water vapor.4 Input parameters are barometric pressure, ambient temperature, relative humidity and carbon dioxide concentration. The default value of any parameter is its standard value. The program can perform single conversions or generate conversion tables for up to 6000 entries per batch.