Simple technique for determining the refractive index of phase-change materials using near-infrared reflectometry (vol 10, pg 1675, 2020) - Gemo, E; Kesava, SV; De Galarreta, CR; Galarreta, L; Carrillo, SGC; Riede, M; Baldycheva, A; Alexeev, A; Wright, CD (Optical Materials Express, 2020)