All Problems

Interference of Light

Problem 5.79

A parallel beam of white light falls on a thin film whose refractive index is equal to \(n=1.33 .\) The angle of indices is \(\theta_{1}=\) \(=52^{\circ} .\) What must the film thickness be equal to for the reflected light to be coloured yellow \((\lambda=0.60 \mu \mathrm{m})\) most intensively?

Reveal Answer
 5.79. d=1/4λ(1+2k)/n2sin2θ1=0.14(1+2k)μm, where k=0,1,2,\begin{aligned} &\text { 5.79. } d=1 / 4 \lambda(1+2 k) / \sqrt{n^{2}-\sin ^{2} \theta_{1}}=0.14(1+2 k) \quad \mu \mathrm{m}, \text { where }\\ &k=0,1,2, \ldots \end{aligned}