Sculpting Light: Using Photon Momentum to Create New Imaging Techniques

Imaging is one of the oldest and most applied of the sciences, dating back at least two millennia to the first lenses and Euclid’s Optics. Until recently, most if not all optical elements, such as lenses, diffraction gratings and phase plates, have functioned by acting on a photon’s position. In contrast, this talk will describe our experiments that rely on a photon’s momentum, i.e. its angle, to create novel types of imaging systems. For example, we have used photon pairs that are quantum-entangled in momentum to image in the presence of turbulence, background light, and even without aiming a camera at the object.  For single photons, I will show that through controlling momentum one can create arbitrary optical transformations, including that of free-space itself. The latter effectively compresses optical propagation into a thin plate, a device we call a “spaceplate”. If perfected, spaceplates could one day replace the space between a lens and the imaging sensor, enabling flat thin cameras.  I will finish by outlining prospects for even more exotic and useful imaging systems that function by acting on a photon’s momentum.