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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.n=1.33 . The angle of indices is θ1=\theta_{1}= =52.=52^{\circ} . What must the film thickness be equal to for the reflected light to be coloured yellow (λ=0.60μm)(\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}