New Ways with Atomic Levels

Carlos L. Garrido Alzar, Luciano Soares da Cruz, J. G. Aguirre Gómez +7 more

We present a series of experiments measuring intensity fluctuations and correlations of laser beams after propagation through an atomic vapour at room temperature in situations where coherent effects play a major role. In particular, we investigate these properties in the condition of electromagnetically induced transparency (EIT) in three-level lambda systems and in degenerate two-level systems. In a similar way, we also study the Hanle-EIT effect and electromagnetically induced absorption (EIA) in degenerate two-level systems. These results show the great influence of coherent interaction with the atomic system over the noise properties of the macroscopic laser fields, and indicate new sensitive ways of probing an atomic sample.

Otto Robert Frisch

Oskar J. Painter

Zongfu Yu

We show that quantum antenna and metasurface can be realized by a cluster of quantum two level systems such as atoms or quantum dots. They offer a new way to dynamically control non-classical light with sophisticated functionalities.

Gongwei Lin, Shicheng Zhang, Yiqi Hu +3 more

Optical nonreciprocity is of paramount importance to optical signal processing and one-way optical communication. Here, we theoretically and experimentally demonstrate nonreciprocal amplification based on four-level hot atoms by exploiting atomic Doppler shifts. Our approach is simple and easy to implement. In fair agreement with our theoretical modeling, forward power amplification of 26 dB and backward isolation of 30 dB are observed. Our results will open up a new avenue towards realistic devices based on nonreciprocal amplification.

Nelson Frederick Beeler, Franklyn Mansfield Branley