Atom-light hybrid interferometer

We will report on our latest experimental result on atom-light hybrid interferometer. We demonstrated a new type of hybrid atom-light interferometer [1] with two atomic Raman amplification processes (RA1 and RA2) replacing the beam splitting elements in a traditional interferometer. Different with conventional optical interferometer, the first beam splitter process in atom-light hybrid interferometer is a Raman amplification process, which generates a Stokes field (optical field, S
1
) and an atomic spin wave (S
a1
). The phase of the Stokes field and atomic spin wave are anti-correlated to each other [2], so the nonconventional interferometer involves correlated optical and atomic wave in the two arms. Then the Stokes field S
1
travels out of the atomic vapor and the atomic spin wave S
a1
stays in the atomic vapor. After some delay time, to recombine the Stokes field and the atomic spin wave for interference, we return the Stokes field S
1
back into the atomic vapor together with another strong Raman pump field. The delay is necessary so as to temporally separate the wave splitting and recombination processes because we are using the same atomic cell for the two processes. Finally, we observed the high-contrast interference fringes at two outputs. The interference fringes are sensitive to the phase of optical field via a path change as well as the phase of atomic spin wave via a magnetic field change. This new atom-light correlated hybrid interferometer is a sensitive probe of the atomic internal state and should find wide applications in precision measurement and quantum control with atoms and photons.