Theory of Newton Ring

Abstract

This experiment looks to investigate the physical optics of the interference pattern called Newton’s rings and calculate the wavelengths of various filters as well as the radius of curvature of a plano-convex lens. Through the consideration of the wavelength dependence of the diameter of the rings, mathematical relationships are derived and applied on the measured data to verify the known wavelength values. The results produced by the data successfully show the relationship between diameters of the rings, their order, the refractive index of the medium causing the interference pattern and the wavelength of the incident light. Graphical analysis confirms that the diameters of the rings are larger at higher orders, and larger still for longer incident wavelengths.