Question

When newton ring produced reflection sodium light radii dark ring?

Answer 1

Newton's rings observed through a microscope. The smallest increments on the superimposed scale are 100μm. The illumination is from below, leading to a bright central region.



Newton’s rings interference pattern created by a plano-convex lensilluminated by 650 nm red laser light, photographed using a low-light microscope. The illumination is from above, leading to a dark central region.



The experimental setup: a convex lensis placed on top of a flat surface.

Newton's rings is a phenomenon in which an interference pattern is created by the reflection of light between two surfaces—a spherical surface and an adjacent touching flat surface. It is named for Isaac Newton, who first studied the effect in 1717. When viewed with monochromatic light, Newton's rings appear as a series of concentric, alternating bright and dark rings centered at the point of contact between the two surfaces. When viewed with white light, it forms a concentric ring pattern of rainbow colors, because the different wavelengths of light interfere at different thicknesses of the air layer between the surfaces.