The history of this experiment goes back to 1801 when British polymath Thomas Young demonstrated the wave nature of light and hence, is often called Young’s double-slit experiment. To locate the fringes from the center of the screen, one assumes that the distance between the screen and slit is much greater than the distance separating the slits. Also, the separation between the slits is much greater than the wavelength of the monochromatic light. By measuring the separation between the fringes and knowing the distance of the screen from the slits and distance between the two slits, it is possible to determine the wavelength of light.
