Applied Physics/Physics Colloquium: Giulio Vampa - "Quantum-optical Properties of High-Harmonic Generation"

Abstract: The emission of high-order harmonics of intense femtosecond lasers has long been understood as a result of a short-lived and rapidly oscillating “quantum antenna”: the result of the dynamical interference of the wavefunctions of an accelerated electron and that of its correlated hole, setup by an intense laser field during its interaction with matter. Ever since its discovery and understanding in the 1980s-90s, the emitted light has always been considered as a classical electromagnetic field, even though it is typically extremely weak. In the last five years or so, however, the investigation of the quantum-optical properties of high-harmonic generation has gained significant traction. In my talk I will introduce the unlikely merge of high-field attosecond science and quantum optics, and the oxymoron within it. I will present our latest work aimed at uncovering and inducing quantum-optical properties of the emitted high-harmonics, as well as our application of an attosecond metrology technique to resolve the field oscillations and other temporal structures of femtosecond bright squeezed vacuum, a quantum optical state.

 Giulio Vampa is a Senior Research Officer at the National Research Council of Canada in Ottawa, and a member of the Joint Attosecond Science Laboratory (JASLab) between NRC and the University of Ottawa. He is an adjunct professor of physics at the University of Ottawa and at the Institut National de la Recherche Scientifique in Montreal, a fellow of the Joint Center for Extreme Photonics (JCEP) and of the Nexus for Quantum Technologies (NexQT) at uOttawa. He obtained his PhD in Physics at the University of Ottawa in 2015, followed by a four-year postdoc at the Stanford PULSE Institute. He joined NRC in 2020. Giulio is member of Optica and of the American Physical Society (APS). His interests encompass the fundamentals and the applications of attosecond science in materials and nanostructured solids.