The Role of Phases in the Transient Dynamics of Nonlinear Interferometers

G. L�pke, Gerd Marowsky, Robert Steinhoff

B. Wedding, Armin Gasch, D. Jäger

The dynamic properties of a Fabry–Perot interferometer filled with a material exhibiting second-order dispersive nonlinearity are studied both theoretically and experimentally. The response of the medium is described by an intensity dependent phase constant as derived from self-action effects. Considering two relaxation times, that of the material and that of the cavity, the basic relations for the stability analysis and for the numerical calculations are obtained. Bistability and self-pulsing effects are predicted. Moreover, the transient behavior is characterized by anomalous switching properties like overshoot and alternate switching. The corresponding experiments performed on a nonlinear transmission line resonator confirm the theoretical results. In a final discussion, the relations to the field of nonlinear optics are outlined.

Michael Vern Pack, Ryan M. Camacho, John C. Howell

We report observations of the dynamics of electromagnetically induced transparency (EIT) in a $\ensuremath{\Lambda}$ system when the ground states are Stark shifted. Interactions of this type exhibit large optical nonlinearities called Kerr nonlinearities, and have numerous applications. The EIT Kerr nonlinearity is relatively slow, which is a limiting factor that may make many potential applications impossible. Using rubidium atoms, we observe the dynamics of the EIT Kerr nonlinearity using a Mach-Zehnder interferometer to measure phase modulation of the EIT fields resulting from a pulsed signal beam Stark shifting the ground state energy levels. The rise times and transients agree well with theory.

Агишев Игорь Николаевич, N.A. Ivanova, Alexei L. Tolstik

F. A. Hopf, Pierre Meystre

Jiandong Zhang, Fan Jia, Lili Hou +1 more

Classical and quantum states working in concert play an essential role in high-precision interferometry. In this regard, coherent combined with squeezed vacuum states are the most promising candidate. Here we complement this subject by comparing nonlinear and nonlinear-linear hybrid interferometers with homodyne detection as a readout strategy. For a high-photon coherent state, either of the two interferometers can provide the phase sensitivity approaching the quantum Cramer-Rao bound. Additionally, we discuss the impacts of photon loss during the transmission and readout stages. We find that a nonlinear interferometer is advantageous over a nonlinear-linear hybrid interferometer. With increasing photon number of the coherent state, the maximal tolerable lossy rate ensuring phase sensitivity beyond the shot-noise limit is close to 50%. Our work may deepen the understanding of quantum-enhanced interferometry using nonlinear dynamics.