Sb<sub>2</sub>S<sub>3</sub> as a low-loss phase-change material for mid-IR photonics
Adam Biegański, Marko Perestjuk, Rémi Armand, Alberto Della Torre, Capucine Laprais, Guillaume Saint‐Girons, Vincent Reboud, Jean‐Michel Hartmann, J.H. Tortai, Antonin Moreau, Julien Lumeau, Thach G. Nguyen, Arnan Mitchell, Christelle Monat, Sébastien Cueff, Christian Grillet
Abstract
We study the mid-IR optical properties of Sb 2 S 3 – a phase-change material (PCM) with high potential for mid-IR integrated photonics. We show that Sb 2 S 3 exhibits a high refractive index contrast Δn ≈ 1 between its two phases and an extinction coefficient k below 10 −2 at mid-IR wavelengths (up to ∼10 µm). We study the impact of 100 nm Sb 2 S 3 cladding on SiGe-on-Si waveguides and experimentally show that it brings additional propagation loss below 1 dB/cm in the 3.3–3.9 µm wavelength range in both phases. These findings pave the way for new uses of Sb 2 S 3 in mid-IR integrated photonics.