Figure 4
From: Impact of GST thickness on GST-loaded silicon waveguides for optimal optical switching

GST crystalline. Propagation losses (solid line) and coupling (dotted line) for the three supported optical modes: (a) fundamental GST TE-like (mode 0), (b) hybrid (mode 1), and (c) Si TE-like (mode 2). Insets show the electric-field distribution |E| for a certain GST thickness.