The present experimental study focuses on improving the photo-thermal and nonlinear responses of nano-silver across different sizes and shapes. Samples include; spherical silver nanoparticles (Ag NPs) of various sizes (20, 50, and 68 nm), prepared via the Laser Ablation in Liquid (LAL) method using a Nd:YAG pulsed laser at different energies (100, 300, and 500 mJ) respectively. Additionally, silver nanowires (Ag NWs) with different wire diameters (50, 100, and 200 nm) were obtained from the German company Plasma Chem. Furthermore, silver nano-hexagonal structures (Ag NHs) were also examined with different sizes (50, 100, and 200 nm), which were synthesized by the chemical reduction method. The dispersion of all samples was carried out in deionized distilled water (DW) with a refractive index of 1.33, and analyzed using UV–Vis spectroscopy, TEM, FE-SEM, and photothermal response measurements by monitoring the nano-silver samples 405 nm CW lasers at 50 mW for 4 minutes, the local temperature elevation of the samples was recorded. In addition, the Z-scan technique was employed to evaluate the nonlinear refractive index and nonlinear optical responses of all investigated samples. The results showed that the plasmonic properties as well as the linear and nonlinear optical properties can not only be tuned by controlling the shape and size of the nano-silver but also leading to a marked enhancement in thermo-plasmonic behavior with respect to temperature elevation. Additionally, experimental findings demonstrated that the laser-induced temperature elveation of nano-silver holds great promise for sterilizing and disinfecting medical devices.