A transparent film (n = 1.4) is deposited on a glass lens (n = 1.5) to form a non-reflective coating. What thickness would prevent reflection of light with wavelength 5.00 × 10²nm in air?

Question

Quizplus · Accepted Answer

For non-reflective coating, the thickness should be a quarter of the wavelength in the film. The wavelength in the film is the wavelength in air divided by the refractive index of the film: (500 nm / 1.4) / 4 = 89 nm.

A Transparent Film (N = 1