The wave-particle duality of light and matter is a fundamental concept in quantum mechanics. While it is true that light exhibits wave-like behavior, it is not entirely accurate to say that light is only a wave phenomenon except when it interacts with matter in a quantized way. The wave-particle duality implies that light can exhibit characteristics of both waves and particles, depending on the experimental setup and the phenomena being observed.
In certain experiments, such as the double-slit experiment, light behaves like a wave, displaying interference patterns that are characteristic of wave phenomena. However, other experiments, like the photoelectric effect, demonstrate particle-like behavior of light, where it behaves as discrete packets of energy called photons.
The behavior of light (and other particles) is described by quantum mechanics, which provides a mathematical framework to understand and predict their properties. According to quantum mechanics, light can be described by wavefunctions, which are mathematical entities that exhibit wave-like behavior. These wavefunctions can be used to calculate probabilities of finding particles (in this case, photons) in certain states or locations.
So, it is not accurate to say that light is only a wave phenomenon. Light exhibits both wave-like and particle-like behavior, and its interaction with matter is described by the principles of quantum mechanics, which involve quantization and probabilistic predictions. The wave-particle duality is a fundamental concept that captures the complex nature of light and matter at the quantum level.