Question

Assume that the polymer material has a constant refractive index of 1.5. For light of 600nm wavelength at normal incidence, what should the smallest thickness of polymer film be, to reflect minimal light on a perfectly reflective substrate

Answer 1

Answer:

Minimum thickness will be 100 nm

Explanation:

We have given refractive index is n = 1.5

Wavelength of the light incidence $\lambda$= 600 nm

We have to find the smallest thickness of the film so that there will be minimum light reflect

For minimum thickness of non reflecting film

$t=\frac{\lambda }{4n}$ , here t is thickness, $\lambda$ is wavelength and n is refractive index

Putting all values $t=\frac{600}{4\times 1.5}=100nm$

So minimum thickness will be 100 nm