Photon statistics for Fock and coherent states interfering in a beamsplitter
Jhordan Santiago · Revista Brasileira de Ensino de Física · 2025
We present a straightforward yet comprehensive theoretical study of different quantum states emerging from a bi-modal beamsplitter when various input states interfere. Specifically, we analyze the output states for different combinations of input fields, including Fock states | n ⟩ | m ⟩, hybrid states | n ⟩ | α ⟩, and coherent states | α ⟩ | β ⟩. We derive explicit expressions for the output state vectors, calculate the mean photon number, photon number variance, Mandel Q parameter, and second-order coherence function to characterize the statistical properties of the output fields. Our results are intended as a pedagogical resource, serving as an introductory reference for students and researchers aiming to understand basic photon statistics using beamsplitters.