Direct method of extracting complex refractive index from routine Fourier transform infrared reflectance/transmittance measurements
Braden E. Czapla, Leonard M. Hanssen
We describe an algorithm to extract the complex refractive index of a material from reflectance and transmittance measurements commonly taken by spectrophotometers. The algorithm combines Kramers- Kronig analysis with an inversion of Fresnel's equations to provide a direct method of solving for the refractive index which is accurate, even for weakly absorbing materials. We discuss the details of the uncertainty analysis of the algorithm. The algorithm is validated by extracting the complex refractive index of polydimethylsiloxane between 2 micrometers and 18 micrometers and comparing against existing literature.
and Hanssen, L.
Direct method of extracting complex refractive index from routine Fourier transform infrared reflectance/transmittance measurements, SPIE Optics Photonics 2020 Digital Forum, San Diego, CA, [online], https://doi.org/10.1117/12.2568502
(Accessed July 2, 2022)