Single-photon laser driven four-wave mixing in NO

Alexander L. Gaeta

Sun Jiang

In order to study the Rydberg state of Barium atom,single photon resonant degenerate four-wave mixing(FWM)was used to measure the 6s6p1P1 energy level of Barium atom,and FWM specture signal under different experimental conditions were achieved.The results showed that the influence of temperature and laser intensity on FWM are relatively obvious but the buffer gas pressure is relatively poor.These results may serve as a useful reference in further research work on the Rydberg state of Barium atom.

Daniel Groll, Daniel Wigger, Kevin Jürgens +6 more

The Jaynes-Cummings (JC) model is at the heart of cavity QED and suitable to describe many different systems. Here, the authors use it to investigate a quantum dot strongly coupled to a micropillar cavity. Supported by experiments, they apply four-wave mixing spectroscopy to study the system's dynamics. They push the limits of JC physics by injecting up to $\ensuremath{\sim}20$ photons using ultrashort laser pulses. Starting with complicated dynamics, the signal evolves into a single-frequency oscillation monitoring the relaxation down the JC ladder.

N. Bloembergen

Alexander S. Zibrov

We describe several novel experimental effects resulting from optical coherences in multilevel atoms driven with coherent laser fields. Four configurations were explored using Rb vapor cells: lambda dark-line resonances, single beam double-lambda oscillations, and cascade two-photon transitions in co- and counter-propagating geometries. Experiments were performed with high spectral-resolution using low-power diode lasers sources and optically thick cells. Two of the most striking effects we observed are: (1) a self-oscillation that occurs at 3.0 GHz on the 85Rb hyperfine frequency when a single laser field pumps the atoms, and (2) a coherent blue-beam emission that we observe in the co-propagating cascade two-photon case. These phenomena lead to complex lineshapes, and the effects sometimes dominate the well-known 3-level coherence effects. Additional higher-order mixing or cascaded interferences are apparent in all four experimental configurations. Many of these can be viewed as multi-wave mixing enhanced by optical coherences around closed-loop paths of atomic energy levels. The effects are particularly strong when four-photon closed-loop paths with resonant energy levels are possible, as in, the double-lambda system or as a four-wave mixing “box.”

Karsten K. Rottwitt