Magnetooptical spectrometer based on photoelastic modulator with optical feedback and its application in study of f-electron materials

•A magnetooptical spectrometer based on photoelastic modulator was designed and established.•MCPL degree and PL spectra of HoYAG associated with 5S2 → 5I8 transition are studied.•The Faraday rotation in the range of 420–700 nm in TbScAG is measured.•The effective frequency (λ0 = 273 nm) of the allowed 4f → 5d transitions in Tb3+ ions is found.

A spectroscopic apparatus for measurement of magnetooptical and optical properties of f-electron materials has been designed and established using a polarization modulation technique based on photoelastic modulator with optical feedback. The magnetooptical system is able to provide a sensitivity of 0.004 arc-deg at the wavelength of 380 nm. The versatile applications of the spectrometer have been verified by the measurements of the magnetic circular polarized luminescence and Faraday rotation angle in holmium- and terbium-containing garnet crystals.