Ancilla-free scheme for the photon-addition operation and its application to squeezing and coherence manipulation

The photon-addition operation is the inverse of the photon-subtraction operation and has many important applications in research on photon number statistics in quantum optics. In this study, we propose a scheme for a photon-addition operation with ancilla-free photonic manipulation. This is in strong contrast to conventional photon-addition operations in which a single-photon ancilla is an indispensable resource for photon addition. Moreover, our scheme helps break the exponential decay trend in the probability of success for photon addition operating in large Fock states. Thus, our scheme can be considered as a useful tool for manipulating the photon number of a bright coherent state or a strongly squeezed state in the near future. To be precise, we used the SU(1,1) beamsplitter to replace the conventional beamsplitter, and our work can be considered another important application of the SU(1,1) beamsplitter. The photon-addition operation is applied to both single- and two-mode quantum entangled states, and our results show that SU(1,1)-based photon addition is more powerful and efficient in terms of the fidelity and success probability of the photon-addition operation.