Lecturer: Thomas W. Clark (Wigner RC)
Abstract: Twenty-five years ago this year, Allen, Beijersbergen, Spreeuw, and Woerdman reported that light carries two types of angular momentum: spin (polarization) and orbital angular momentum. Although it had been known for some time that light could exert a momentum of hbar, it was only after the work of Allen et al. that it was understood that the systematic winding of wavefronts could lead to an unbounded source of angular momentum: an inifinite-dimensional phase-space that came with a twist. Such a discovery has had a vast influence across the field of optics, extending through mechanical manipulation, imaging, communications and the quantum realm. In this seminar, I selectively review the creation and manipulation of spatially-structured light, before detailing how this can be applied to interaction with atomic systems. Throughout, I will focus on work undertaken at Glasgow, concluding with recent results on how phase-shaped light can be used to sculpt the refractive index and populations of an atomic cloud.