Film thickness for minimum interference

Interference in thin films is a phenomenon that occurs as a result of the separation of a light beam when reflected from the upper and lower boundaries of a thin film. As a result, there are two light waves that interfere. This law describes the result of their constructive interference.

Links:

1. Thin-film interference.

film_thickness

Film thickness.

Symbol:

h

Latex:

\(h\)

Dimension:

length

wavelength

wavelength of incident light.

Symbol:

lambda

Latex:

\(\lambda\)

Dimension:

length

interference_order

Order of interference. See positive_number. It represents the number of whole wavelengths fitting within the optical path difference between interfering waves when the interference is constructive. The order of interference can be chosen arbitrarily, to achieve the desired thin film thickness.

Symbol:

k

Latex:

\(k\)

Dimension:

dimensionless

refraction_angle

angle of refraction

Symbol:

phi

Latex:

\(\varphi\)

Dimension:

angle

relative_refractive_index

relative_refractive_index of the film.

Symbol:

n

Latex:

\(n\)

Dimension:

dimensionless

law

h = k * lambda / (2 * n * cos(phi))

Latex:

\[h = \frac{k \lambda}{2 n \cos{\left(\varphi \right)}}\]