Polarimetry analysis and optical contrast of Sb 2 S 3 phase change material

Phase-change materials (PCMs) are the cornerstone for the development of reconfigurable and programmable photonic devices. Sb 2 S 3 has been recently proposed as an interesting PCM due to its low-losses in the visible and near-IR. Here, we report the use of imaging polarimetry and spectroscopic ellipsometry to reveal and directly measure the optical properties of Sb 2 S 3 both in crystalline and amorphous states obtained upon crystallization by annealing in the air of chemical bath deposited amorphous Sb 2 S 3 . The Mueller Matrix polarimetric analysis reveals the strong anisotropy of the Sb 2 S 3 crystallites which crystallize in radial spherulitic domains in contrast to the optical isotropy of the amorphous films. A refractive index contrast of Δ n = 0.5 is demonstrated while maintaining low-losses at telecommunications C-band, i.e., λ = 1550 nm.