Specific Features of Laser Modification of Thin Ge2Sb2Te5 Films by the HG01 Mode

Phase-change materials are very interesting and promising objects for various optical applications due to simple and high-speed switching between the amorphous and crystalline states. In this study, we consider the specific features of laser crystallization and ablation of thin amorphous Ge2Sb2Te5 films exposed to the HG01 (Hermite–Gaussian TEM01) mode of cw visible light. This exposure led to two-zone crystallization or ablation, depending on the laser intensity. Microscale two-zone ablation made it possible to observe Young’s fringes for the radiation transmitted through a sample, as in the case of two-point-source interference. This approach is promising for express analysis of the laser beam profile.