Polarization-modulated infrared reflection difference microspectroscopy: Experiment and model

Polarization-modulated infrared reflection difference microspectroscopy is a sensitive tool to spatially and spectrally resolve optical anisotropy of micrometric crystalline domains. However, intrinsic artifacts are associated with polarization modulation experiments, in particular due to the wavenumber-dependent efficiency of the photoelastic modulator. Here an account addressing this problem in our experimental approach is given. Comparing data from measurements on Ca1.4Sr0.6RuO4 and Bi0.3Ca0.7MnO3+δ with model calculations, it is shown that a simple model, which is based on reports in the literature, can be used to describe the experimental results.