Question

How could the inventor make a nonreflective coating for lenses effective at all wavelengths?

a. Use a coating with a high index of refraction and moderate thickness.
b. Use a coating with a low index of refraction and moderate thickness.
c. Use a coating with a high index of refraction and extremely thin thickness.
d. Use a coating with a low index of refraction and extremely thin thickness.

Answer 1

To make a nonreflective coating for lenses effective at all wavelengths, a coating with a low index of refraction and extremely thin thickness should be used.

Step-by-step explanation:

To make a nonreflective coating for lenses effective at all wavelengths, a coating with a low index of refraction and extremely thin thickness should be used. This is because destructive interference occurs when the difference in the optical path length between the two reflected waves is a multiple of the wavelength. By using a low index of refraction and thin thickness, the path length difference can be adjusted to achieve destructive interference for all wavelengths.

If a coating with a high index of refraction or moderate thickness is used, the range of wavelengths at which destructive interference occurs will be limited, making it impractical for achieving non-reflectivity at all wavelengths.