Dynamics of reversible optical properties switching of Ge2Sb2Te5 thin films at laser-induced phase transitions

•Reversable laser-induced phase transition of Ge2Sb2Te5 thin film functional coating and related on this transition’s changes in optical properties.•High optical properties contrast for two stable reversible laser-induced phase states.•Transmissivity and reflectivity changing during thin film laser-induced phase changing process time-resolved study.•Thin film temperature kinetics’ computational model. Paper presents the study of Ge2Sb2Te5 (GST) thin films phase transitions’ dynamics determined by the rate of their optical coefficients change. The phase transitions were initialized by laser pulses with 15 ns duration at a wavelength of 532 nm and confirmed by X-ray diffraction analysis. Energy fluence was 22 mJ/cm2 for film crystallization and 54 mJ/cm2 for reamorphization. The time for a complete change of GST film reflectivity associated with the crystallization process was 23 ns, while the time for a transmissivity change was 32 ns. Taking into account that the reflection is determined to a greater extent by the surface, and the transmission is exclusively by the film thickness, the estimated crystallization rate was ∼3.125 m/s. The time for a complete change in the reflectivity during the film reamorphization 62 ns, and the transmissivity changed in 65 ns. The estimated reamorphization rate was ∼1.538 m/s.