Question

White light containing the wavelengths between 420 and 720 nm traveling in the air falls on a thin layer n1 = 1.5 and a thickness of 0.000001 m. If this layer is placed on another thin film n2 = 1.4, determine the wavelengths of the light that is not reflected in the air.

Answer 1

In this case $n_0<n_1; n_2<n_1(1<1.5;1.4<1.5)$.

So, the phase changes are not common to both surfaces. For destructive interference

$\lambda=\frac{2dn_2}{m}, where$ $m=1,2,3,4,5,....$

We have

$\lambda_5=600nm$

$\lambda_6=500nm$

$\lambda_7=428nm$.