z-porter/kktranz

a package for Kramers-Kronig Transforms of optical data, especially XANES spectra

I present a set of functions for analyzing optical data with Kramers-Kronig (KK) transforms. The functions compute and plot KK transforms with numerical integrals to convert between real and imaginary scattering factors with x-ray data. This may be applied to electronically characterize materials given spectral data, or to check physical consistency of data.

kkReal() outputs the real scattering factors of hard x-rays at the input energy range by computing the KK transform of an input array of imaginary scattering factors. kkImag() outputs imaginary given real scattering factors. kkXANES() outputs both given a normalized XANES spectrum. All are optimized for speed and customizable, yet work with minimal inputs.
Initially used at SLAC National Accelerator Laboratory as a consistency check between reflectometry and absorption data. Code is thoroughly commented and easily adapted for uses beyond the initial one.

This software is distributed under the GNU licence agreement by Zachary Porter, email: zach.porter (at) ucsb (dot) edu

This applies previous software written by Valerio Lucarini, who is unaffiliated with this work. The same transforms work for susceptibility data too. For some relevant applications in nanostructures and polymers, see http://www.springer.com/us/book/9783540236733