Nonreciprocal Amplification with Four-Level Hot Atoms

Gongwei Lin; Shicheng Zhang; Yiqi Hu; Yueping Niu; Jiangbin Gong; Shangqing Gong

doi:10.1103/PhysRevLett.123.033902

Nonreciprocal Amplification with Four-Level Hot Atoms

Phys Rev Lett. 2019 Jul 19;123(3):033902. doi: 10.1103/PhysRevLett.123.033902.

Authors

Gongwei Lin¹, Shicheng Zhang^{1

2}, Yiqi Hu^{1

2}, Yueping Niu^{1

3}, Jiangbin Gong⁴, Shangqing Gong^{1

3}

Affiliations

¹ Department of Physics, East China University of Science and Technology, Shanghai 200237, China.
² School of Materials Science and Engineering, East China University of Science and Technology, Shanghai 200237, China.
³ Shanghai Engineering Research Center of Hierarchical Nanomaterials, Shanghai 200237, China.
⁴ Department of Physics, National University of Singapore, 117542 Singapore.

PMID: 31386465
DOI: 10.1103/PhysRevLett.123.033902

Abstract

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.