Programmable Photonics

Programmable Photonics  aims at designing common integrated optical hardware resource configurations, capable of implementing an unconstrained variety of functionalities by suitable programming following a parallel but not identical path to that of integrated electronics. It is raising a considerable interest, driven by the surge of a large number of new applications in the fields of telecommunications, quantum information processing, sensing and neurophotonics, which  call for flexible, reconfigurable, low-cost, compact and low-power-consuming devices that can cooperate with integrated electronic devices to overcome the limitation expected by the demise of Moore’s Law. Integrated photonic devices exploiting full programmability are expected to scale from application specific photonic chips (featuring a relatively low number of functionalities) up to very complex application-agnostic complex subsystems much in the same way as Field Programmable Gate Arrays and microprocessors operate in electronics. Two main differences need to be considered. First, as opposed to integrated electronics, programmable integrated photonics will carry analog operations over the signals to be processed. In second place, the scale of integration density will be several orders of magnitude smaller due to the physical limitations imposed by the wavelength ratio of electrons and lightwave photons.  In this talk I will  review the basic foundations and principles behind  programmable photonics,  review some practical aspects that limit the programming and scalability of programmable circuits and give an overview of some of the most salient applications demonstrated so far.