A glass lens is coated on one side with a thin film of magnesium fluoride `(MgF_(2))`to
Channel: Doubtnut
Date: 2020-07-26

A glass lens is coated on one side with a thin film of magnesium fluoride `(MgF_(2))`to reduce reflection from the lens surface (Fig. 2.26). The Index of refraction of `MgF_(2)` is 1.38, that of the glass is 1.50. What is the least coating thickness that eliminates (via interference) the reflections at the middle of the visible specturm `(lambda = 550nm)`? Assume that the light is approxmately perpendicular to the lens surface.  img src="https://d10lpgp6xz60nq.cloudfront.net/physics_images/BMS_V04_C02_S01_013_Q01.png" width="80%"