Second Harmonic Generation (SHG) is a nonlinear optical process where two photons of the same frequency interact with a nonlinear material, resulting in the production of a new photon with double the energy and half the wavelength. This phenomenon is commonly observed in crystals like beta barium borate (BBO) and potassium titanyl phosphate (KTP), which are often used in laser applications. SHG is widely utilized in various technologies, including laser systems and optical communication. By converting infrared light into visible light, SHG enables the generation of new wavelengths, enhancing the capabilities of lasers and improving the efficiency of optical devices.