Abstract: A photonic quantum state generator is presented for generation of one or more predetermined photonic quantum states in a range from radiofrequency to X-ray. The generator comprises: a free particles source controllably operable to provide a flow of said free particles with predetermined one or more flow parameters; a shaping unit located in a vicinity of a flow of the free particles and adapted to apply wavefunction shaping to provide coherently shaped free particles in either one of time-energy domain or space-momentum domain; and an interaction unit comprising a photonic structure and defining an interaction region enabling in interactions (m?1) between a photonic mode within said interaction region and the flow of the coherently shaped free particles having said one or more flow parameters satisfying a phase-matching condition with respect to the photonic mode, thereby generating said one or more predetermined photonic quantum states by a conditional displacement mechanism.