A parametric two-photon process, involving stimulated emission of two cascaded photons from a bidoped poled material placed inside an optically pumped cavity, is proposed and assessed within the priming photon scheme. We show that, with a specific level configuration for the two dopants
A and
B, and an appropriate cavity design, stimulated emission from dopant
A can provide the priming photons for stimulated two-photon emission from dopant
B through a parametric biphotonic cascade. We discuss how this process is driven by a ratchet effect introduced by the simultaneous breakdown of both the space and time inversion symmetries. The optical Stark shifts are shown to considerably impact the efficiency of such a cascaded two-photon process.
Photon bunching effect and stimulated emission of single photons is investigated and observed in the parametric amplification process. It is found that the two-photon interference is responsible for the photon bunching effect and stimulated emission, which is discussed in the temporal degree of freedom and in the presence of photon losses. Moreover, the direct measurement of the indistinguishability of two signal photons without any filtering is accomplished via the correlation between the two idler photons from two cascaded parametric down-conversion processes. This result shows that photon indistinguishability plays an essential role in stimulated emission.