Time-resolved switching dynamics of waveguide-integrated chalcogenide cells along the pseudobinary GeTe-Sb2Te3 line

We present a detailed comparative study of the time-resolved switching dynamics and achievable transmission contrast of five compositions along the pseudobinary GeTe-Sb 2 Te 3 line, integrated under identical cell geometry and switching protocol into silicon nitride (SiN) waveguides. We systematically measure the settling time and transmission contrast following tailored optical pulses at telecom wavelengths (C-band) for both amorphization and crystallization. Our results show significant differences in performance across the composition range, identifying specific alloys that provide an excellent combination of high contrast and short settling times and emerge as promising alternatives to the widely used GST225 for SiN-based non-volatile photonic devices.