Abstract Single-photon source in micro- or nanoscale is the basic building block of on-chip quantum information and scalable network. Enhanced spontaneous emission based on cavity electrodynamics (CQED) one key principles realizing single-photon sources fabricated by nanophotonic cavities. Here we mainly review single emitters nanostructures, such as whispering gallery microcavities, photonic c...

The emissions of the prebunched electron beam, including the coherent spontaneous emission and the self-amplified stimulated emission, are analyzed by using one-dimensional FEL theory. Neglecting the interaction of the electrons and the radiation field, the formula of the coherent spontaneous emission is given, the power of which is proportional to the square of the initial bunching factor and ...