A glass lens ( ) is coated with a layer of magnesium-fluoride ( )

PHYSICS · Subjective · A Level · Physics · Waves · Waves

Problem

A glass lens (

n_{\text{glass}}=1.52

) is coated with a layer of magnesium-fluoride (

n_{\text{MF}}=1.38

). Calculate the smallest non-zero thickness of the coating that produces constructive reflection for

\lambda_0=550\;\text{nm}

light at normal incidence in air.