A film of index of refraction n₁ coats a surface with index of refraction n₂.When n₁

Question

A film of index of refraction n₁ coats a surface with index of refraction n₂.When n₁ < n₂,the condition for destructive interference for reflected monochromatic light of wavelength $\lambda$in air is A) $t = m \frac { \lambda } { n _ { 1 } }$ . B) $t = \left( m + \frac { 1 } { 2 } \right) \frac { \lambda } { n _ { 1 } }$ . C) $2 t = m \frac { \lambda } { n _ { 1 } }$ . D) $2 t = \left( m + \frac { 1 } { 2 } \right) \frac { \lambda } { n _ { 1 } }$ . E) $4 t = m \frac { \lambda } { n _ { 1 } }$ .

Quizplus · Accepted Answer

For destructive interference in thin films, the condition is $2t = (m + \frac{1}{2}) \frac{\lambda}{n_1}$ when the film's refractive index $n_1$ is less than the substrate's refractive index $n_2$.

A Film of Index of Refraction N1 Coats a Surface λ\lambdaλ

A Film of Index of Refraction N₁ Coats a Surface $\lambda$