Hello, college physics knowledge point wave function: it is a functional relationship that represents the vibration state of each particle in the medium changing with time, also called wave expression. All the particles in the medium that participate in the fluctuation are constantly receiving energy from the wave source and releasing energy. Energy density of wave: wave energy per unit volume in medium.

Average energy density: the average value of wave energy density in a period.

The average energy density of wave is proportional to the product of the square of amplitude, the square of frequency and the density of medium.

Energy flow: the energy passing through a certain area s in the medium per unit time.

The average energy flow per unit area passing through the vertical Apollo line in unit time is called energy flow density, also known as wave intensity. Electromagnetic wave: the changing electromagnetic field propagates at a certain speed in space.

Radiant energy: electromagnetic energy carried by electromagnetic waves.

Energy flow density s (radiation intensity): the radiation energy passing through the unit area perpendicular to the propagation direction in unit time.

Huygens principle: every point on any wave surface in the medium can be regarded as the wave source that produces spherical waves; At any time after that, the envelope surfaces of these wavelets form a new wave surface.

Coherent wave: a wave that can produce interference phenomenon.

Coherent wave source: A wave source that can excite coherent waves.

Coherence conditions: same frequency, same vibration direction and constant phase difference.

I hope I can help you.