Data for: Optical spectroscopy of single- and two-ion transitions in an antiferromagnetic stoichiometric rare-earth crystal

Transmission spectra for the ground 4I9/2 state to the lowest 4F3/2 doublet of neodymium in magnetically ordered neodymium gallate. There are four files given: sigma- and pi-polarisation for magnetic field applied along the b and c axes of the crystal (in Pbnm setting). Files are provided in matlab format as they can be read easily in many programming languages. Each file has three stored arrays. B = applied magnetic field in Tesla, f = optical frequency in GHz relative to 341644 GHz, transmission = normalised transmission through the sample.