Physics What is the frequency of waves

Wave properties

Light consists of electric and magnetic fields that propagate in waves, i.e. an electromagnetic wave. It is usually represented as a sine wave which is characterized by wavelength, frequency, amplitude and phase.


  • wavelength: As a wavelength λ (lambda) one understands the distance between two points with the same phase. Points that have the same deflection (amplitude) and the same direction of movement over time. The wavelength is usually specified in nm.


  • Frequency: The frequency f indicates the number of full oscillations (periods - T) per unit of time (s) and is measured in Hertz (Hz = 1 / s) according to the German physicist Heinrich Hertz.

    There is a direct physical relationship between the frequency and the wavelength:

Wavelength λ · frequency f = speed of light c


  • amplitude: The amplitude y describes the maximum deflection of an oscillation, i.e. where the wave crest is highest. In the case of light waves, the amplitude cannot always be measured directly; however, the intensity (brightness) depends on it; this can then also be measured


  • phase: The phase π indicates when and where the wave peaks or the wave troughs are - i.e. the oscillation state of a wave

In-phase sine waves

Sine waves of different phases