We will discuss the potential of synchronized optical cavities in the pulsed regime to generate complex mesoscopic quantum states and to implement quantum operations following recent theoretical proposals. Single-photons are a main resource for these targeted protocols, but pure states in well-defined spatio-temporal modes are required in order to perform relevant homodyne measurements. We will present a setup for high-rate single-photons generation, based on exaltation cavities in the pulsed regime, and discuss the way to synchronize this source with another cavity in order to have a quantum memory and to implement new kinds of innovative quantum protocols.