Answer:
The minimum thickness = 83.92 nm
Explanation:
The relation between the wavelength in a particular medium and refractive index [tex]\lambda_n = \frac{ \lambda }{n}[/tex]
where ;
[tex]\lambda[/tex] = wavelength of the light in vacuum
n = refractive index of medium with respect to vacuum
For one phase change :
[tex]2t = \frac{\lambda_n}{2}\\\\where \ \lambda_n = \frac{\lambda}{n}\\\\Then \ \\\\2t = \frac{\lambda}{2n}\\\\t = \frac{\lambda_n}{4n}[/tex]
Replacing 1.43 for n and 480 nm for λ; we have:
[tex]t = \frac{480}{4(1.43)}[/tex]
t = 83.92 nm
Thus; the minimum thickness = 83.92 nm
