Research And Application Of Atom-Light Interaction Based On Raman Scattering

Atom-light interaction has always been a fundamental area of quantum optics. Generally, we use light as the information carrier and atoms for manipulation in precision measurement, quantum information, quantum computing, and other application of quantum optics. Based on Raman scattering in warm atomic-vapor cell, we present a new mechanism of atom-light interaction, realize a new kind of atom-light hybrid interferometer using this interaction, and discuss the problem of noise suppression in this thesis. Four parts are listed as follows:In the first part, we discuss how to enhance Raman scattering. We can make the Raman scattering processes more rapid, efficient, and stable by using feedback and the coherence between atoms and light. These methods are nonlinear processes between atoms and light. See chapter 2 for details.In the second part, we focus on the atom-light linear interaction in Raman process. We present a Rabi-like coherent-superposition oscillation observed between atoms and light driven by a strong optical field in a Raman process. This makes it possible to control the distribution of energy between atoms and light. It can also be used as an atom-light linear beam splitter. See chapter 3 for details.In the third part, we constructed an atom-light hybrid interferometer. we form the new kind of interferometer by preforming the atom-light linear interaction twice. Interference fringes are observed in both the optical output intensity and atomic output in terms of the atomic spin wave strength when we scan either or both of the optical and atomic phases. Such a hybrid interferometer will have a wider application than those traditional ones. See chapter 4 for details.In the fourth part, we investigate the four-wave mixing noise problem in Raman process. We preform the Raman process inside an optical resonant cavity. The transmission characteristics of the optical resonant cavity can help to increase the atom-light coupling efficiency and decrease the four-wave mixing noise at the same time. We report the lowest unconditional noise floor yet achieved in warm vapor Raman process. See chapter 5 for details.