Diffraction, Talbot Oscillations and Fourier Optics in the Undergraduate Physics Laboratory

Diffraction experiments in the Fraunhofer and Fresnel regimes and their analysis using Fourier optics are discussed. The focus is on gratings, but to emphasize the mathematical details, results on single slits are also presented. Measurements in the Fraunhofer regime form the basis of this study. The Fresnel regime is explored by bringing the diffracting object and the camera closer together. The power of the Fourier analysis is particularly evident, when studying self-imaging via the Talbot effect and Talbot oscillations at gratings. Expressions are derived for the amplitude oscillations of Fourier space patterns, enabling the Talbot length to be determined precisely. These experiments are designed for use in second-year undergraduate general physics laboratories.