Optical properties and dispersions of rhombohedral 0.24Pb(In1/2Nb1/2)O3–0.49Pb(Mg1/3Nb2/3)O3–0.27PbTiO3 single domain single crystal

•Optical properties and their dispersions were measured for PIN–PMN–PT single crystal.•Bandgaps have been determined at room temperature and 200 °C.•Obtained the refractive indices and the extinction coefficients in the single-domain state.•The parameters of room temperature monomial Sellmeier oscillator were also derived.

The ternary relaxor-based ferroelectric single crystal 0.24Pb(In1/2Nb1/2)O3–0.49Pb(Mg1/3Nb2/3)O3–0.27PbTiO3 (0.24PIN–0.49PMN–0.27PT) poled along [1 1 1]c has remarkable optical properties. Its Curie temperature Tc is 168 °C determined by the dielectric constant measurement. Optical transmission spectra were recorded at both room temperature and 200 °C. The optical absorption edge at 200 °C has an obvious red-shift compared with that at room temperature, the bandgaps were determined to be Eg = 3.18 eV and 2.95 eV at room temperature and at 200 °C, respectively. Parameters for the Varshini equations are: Eg(0) = 3.27 eV, a = 1.62 × 10−3 meV/K and b = 1315 K. We have obtained the refractive indices and the extinction coefficients in the single-domain state. The parameters of room temperature monomial Sellmeier oscillator were also derived.