The optical properties of strontium titanate (SrTiO
3) single crystals were determined with spectroscopic ellipsometry in the 1–6 eV spectral region and the 4.2–300 K temperature region.New results regarding features of band edge and near band edge indirect and direct fundamental optical transitions were obtained and updated.It was shown that whereas the indirect transitions lowest in energy shift to higher energies on cooling, the energy of the stronger direct optical transitions in the region of 3.7–4.0 eV shifts to the opposite side, to lower energies , and these transitions can be treated as the "soft electronic band".
doi:
http://dx.doi.org/10.1088/1367-2630/11/8/083024 
