Light, or more generally the optical electromagnetic field, has two important properties, phase and polarization, both not visible to the naked eye. The phase structure in space determines the light subsequent propagation, while the polarization is mainly important in the interaction with matter. For a single quantum particle of light – the photon – the phase spatial structure is sometimes defined as the “orbital” degree of freedom, as it defines the photon trajectories, while the polarization is related to the “spin” degree of freedom, which could be visualized as an intrinsic rotation of the photon. In most optical phenomena, these two degrees of freedom are rather independent, but recently, a growing number of systems is being discovered, or artificially engineered, in which the photon spin-orbit interactions are important. PHOSPhOR is aimed at investigating these interactions and exploiting them for enhancing our control of the light spatial and temporal structure, with possible benefits for many applications, including optical communication, quantum information technology, photo lithography, etc.
PHOSPhOR vision is to promote the development of a full-fledged spin-orbit photonic science and technology, in which the vector states of structured light beams, optical pulses and even quantum states of individual photons can be precisely tailored and manipulated in all their aspects and used, in combination with suitable material systems, to obtain new classical- or quantum-optical functionalities; or they can be exploited as scientific tools to investigate new physical phenomena.
