The purpose of this lab is to help the student become more familiar with, or get a better feel for what is actually occurring, when observing the effects of double slit diffraction patterns. In most sophomore labs dealing with double slit diffraction, the student simply determines the diffraction angle, and slit spacing, from marking the positions of the maxima on the screen. No attempt is made to measure the relative intensity of the interference pattern, and see how the experimental data compare with the theory of interference and diffraction. In an attempt to further clarify this phenomena, we will attempt to measure the relative intensities of various double slit diffraction set ups, and compare the actual results with the corresponding theoretical values. It may prove very helpful for the student to review chapters 40 and 41, of Halliday and Resnicks' Fundamentals of Physics, prior to commencement of this exercise.
Jeff Adams (with JR Dennison),, "Fresnel and Fraunhofer Diffraction: Development of an Advanced Laboratory Experiment," Senior Project, Utah State University, Logan, UT, December 1990.