All Problems Diffraction of Light
Problem 5.103
A plane light wave with wavelength \(\lambda=0.60 \mu \mathrm{m}\) falls normally on a sufficiently large glass plate having a round recess on the opposite side (Fig. 5.21 ). For the observation point \(P\) that recess corresponds to the first one and a half Fresnel zones. Find the depth \(h\) of the recess at which the intensity of light at the point \(P\) is (a) maximum; (b) minimum; (c) equal to the intensity of incident light.
5.103. (a) \(h=\lambda(k+3 / 8) /(n-1)=1.2(k+3 / 8) \mu \mathrm{m} ;\) (b) \(h=\) \(=1.2(k+7 / 8) \mu \mathrm{m},(\mathrm{c}) h=1.2 k\) or \(1.2(k+3 / 4) \mu \mathrm{m} .\) Here \(k=\) \(=0,1,2, \ldots\)