Harmonic generation

Harmonic generation is a phenomenon where light or other waves interact with materials to create new waves at multiple integer frequencies of the original wave. When a powerful laser beam passes through certain crystals or nonlinear materials, the interaction can produce light at double, triple, or even higher multiples of the original frequency, effectively changing the light's color and properties. This technique is incredibly useful in science and technology, allowing researchers to convert infrared light into visible or ultraviolet light and enabling everything from advanced microscopy to laser surgery.