# Light wave

Use this calculator to convert one of the following light wave characteristics into another : frequency, wavelength, photon energy, temperature, wavenumber, spectroscopic wavenumber and color (for visible light).

## Light wave formulas

We consider a light wave which propagates in a medium of refractive index n = 1 (ie air or vacuum). Its characteristics are denoted as follows,

f: frequency in hertz (Hz)

`lambda`: wavelength in meter (m)

E: a photon energy in joule (J)

T: Temperature in Kelvin (K)

n: wavenumber in rad/m

ns: spectroscopic wavenumber in 1/m or m^{-1}

c: speed of light in vacuum

### Relationship between frequency and wavelength

`f = c/lambda`

### Photon energy

`E = (h*c)/lambda`

h is the Planck constant, h = 6.62607015.10^{-34} J.s

### Temperature

Temperature is calculated by using Wien law formula which establishes a relationship between the temperature of a body emitting radiation and the wavelength of peak emission `lambda_max`.

`T = (2.8977719 * 10^(-3))/ lambda_max`

with T in Kelvin and `lambda_max` in meter.

### Wavenumber

The wavenumber also called angular wavenumber is calculated as follows,

`n=(2*pi)/lambda`

### Spectroscopic wavenumber

`ns=1/lambda`

## See also

Wave Calculators

Physics Calculators

Unit Converters