Which describes the reflection phase shifts when light refle

Which describes the reflection phase shifts when light reflects from an interface?

   The shift is 0 wavelength if the index on the other side is greater. The shift is 1.0 wavelength if the index on the other side is smaller.

   The shift is 1.0 wavelength if the index on the other side is greater. The shift is 0 wavelength if the index on the other side is smaller.

   The shift is 0 wavelength if the index on the other side is greater. The shift is 0.5 wavelength if the index on the other side is smaller.

   The shift is 0.5 wavelength if the index on the other side is greater. The shift is 0 wavelength if the index on the other side is smaller.

When light reflects from a thin film back toward the source, what is the path length difference of the reflected rays?

   It is equal to half the thickness of the film.

   It is equal to twice the thickness of the film.

   It is equal to the thickness of the film.

and why?

Solution

1st answer : The shift is 0.5 wavelength if the index on the other side is greater. The shift is 0 wavelength if the index on the other side is smaller.

2nd answer : It is equal to twice the thickness of the film.