In: Physics
A thin film of MGF2 has a refractive index of n = 1.38 and it is deposited on glass as an anti-reflective layer of light with a wavelength of 580nm which falls in the normal direction towards the film. What wavelength is minimally reflected when the light falls at 45 ° towards the film?
Here,
Refractive index of MGF2
Incidence light wavelength
Incidence angle
Order of the destructive fringe
Thickness of the film
For an anti reflection, the optical path difference is given by:
For minimum thickness
Now, wavelength at which the destructive interference occurs:
Therefore, minimally reflection occurs at 820 nm light wavelength.