Experimental results on some physical and optical properties of (As₂Se₃)_1-x:Sn_x and (As₄S₃Se₃)_1-x:Sn_x (x = 0 ÷ 10 at %) glasses and amorphous films (d ~ 2:0 μm) are presented. The bulk chalcogenide glasses are studied by X-ray diffraction spectroscopy and nanoindentation methods. It is established that the addition of these amounts of tin (x = 0 ÷ 10 at %) does not lead to significant changes in the physical properties of the glass, such as values of stress and Young’s modulus related to the modification of the density and compactness. The XRD measurements show that the Sn impurities in the (As₄S₃Se₃)_1-x:Sn_xdo not significantly change the shape of the first sharp diffraction peak (FSDP) of the X-ray diffraction patterns either; the intensity and the position of the FSDP nonmonotonically depend on the Sn concentration. It has been found that the addition of these amounts of tin in (As₄S₃Se₃)_1-x:Snx does not lead to significant changes in the glass physical properties, such as values of stress and Young’s modulus related to the modification of the density and compactness. The study of the photoplastic effect is performed in situ, with illumination of the bulk and thin film samples during indentation as well as their indentation after illumination with a green laser (λ = 532 nm) at a power of P = 50 mV/cm². The hardness is calculated from load-displacement curves by the Oliver–Pharr method. A sharp increase in hardness is registered if the tin concentration exceeds a value of 3–4% Sn. The hardness H of (As₄S₃Se₃)_1-x:Sn_x films varies between 115 and 130 kg/mm². It is found that the hardness H of amorphous thin films is generally higher than the hardness of bulk samples with the same chemical composition. In this study, we are focused on the mechanical characteristics of high-purity As₂Se₃:Sn_x thin films.