Generation of Bessel beams using a 4-f spatial filtering system

We demonstrate a simple and straightforward method of producing Bessel beams using a 4-f spatial filtering system that requires no specialized optical components. The experiment employs the established technique of diffraction from a thin ring source, but the ring source is produced by the high-pass filtering of a uniformly illuminated circular aperture, yielding Bessel beams with a central spot radius of less than 35 mu m which persist over a distance of 160 mm. The experiment unifies diffraction theory, Fourier optics, and the properties of Bessel beams in a manner appropriate for an advanced undergraduate laboratory.