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.