Formula: Destructive Interference Condition Path difference Integer Wavelength
$$\Delta s ~=~ \left( m - \frac{1}{2} \right) \, \lambda$$
$$\Delta s ~=~ \left( m - \frac{1}{2} \right) \, \lambda$$
$$m ~=~ \frac{ \Delta s }{ \lambda } ~+~ \frac{1}{2}$$
$$\lambda ~=~ \frac{ \Delta s }{ m ~-~ \frac{1}{2} }$$
Path difference
$$ \Delta s $$ Unit $$ \mathrm{m} $$
The path difference of two waves, which travel to the observation point (e.g. to the point where a bright interference fringe can be seen). The path difference thus indicates by how many wavelengths a wave leads or lags another wave.
For destructive interference, the path difference takes the following values: \[ \Delta s ~=~ \frac{1}{2} \, \lambda,~ \frac{3}{2} \, \lambda,~ \frac{5}{2} \, \lambda, ~... \]
Integer
$$ m $$ Unit $$ - $$
Integer multiple of the wavelength takes the following values in the case of destructive interference: \( m = 1, 2, ... \). This integer indicates the factor by how much one wave precedes the other.
Wavelength
$$ \lambda $$ Unit $$ \mathrm{m} $$
Wavelength of the two waves under consideration. So the wavelength of the light used.