In 1936, Alexandru Proca put forward the idea of a massive photon, as a means to resolve the infinite electromagnetic energy of a point charge in Maxwell's theory. Proca's proposal quickly became and remains the theoretical cornerstone to non-linear optics.
In 2014, Gianmassimo Tasinato and, independently, Lavinia Heisenberg introduced the notion of a generalized massive photon, classically extending Proca's framework through derivative self-interactions. Their motivation was to construct the vector analogue of Galileons.
In this talk, I will discuss work in progress together with Marina Krstic Marinkovic, where we quantize the latter theory and relate it to the former, advancing the idea that Generalized Proca is the befitting conceptualization for recent optical observations.