Bidirectional interconversion of microwave and light with thin-film lithium niobate

• Published in: Nature communications Vol. 12; no. 1; p. 4453
• Main Authors: Xu, Yuntao, Sayem, Ayed Al, Fan, Linran, Zou, Chang-Ling, Wang, Sihao, Cheng, Risheng, Fu, Wei, Yang, Likai, Xu, Mingrui, Tang, Hong X.
• Format: Journal Article
• Language: English
• Published: London Nature Publishing Group UK 22-07-2021; Nature Publishing Group; Nature Portfolio
• Subjects: 639/624/1075/1081; 639/624/1075/401; 639/766/1130/1064; 639/766/1130/2799; Computer architecture; Cryogenic temperature; Cryopumping; Efficiency; Electro-optics; ENGINEERING; Humanities and Social Sciences; Hybrid systems; Lithium; Lithium niobates; Microwave photonics; multidisciplinary; Nonlinear systems; Optics; optoelectronic devices and components; photonic devices; Photons; Photorefractivity; Quantum entanglement; Quantum mechanics; Science; Science (multidisciplinary); superconducting devices; Superconductivity; Thin films
• ISSN: 2041-1723; 2041-1723
• DOI: 10.1038/s41467-021-24809-y

Superconducting cavity electro-optics presents a promising route to coherently convert microwave and optical photons and distribute quantum entanglement between superconducting circuits over long-distance. Strong Pockels nonlinearity and high-performance optical cavity are the prerequisites for high conversion efficiency. Thin-film lithium niobate (TFLN) offers these desired characteristics. Despite significant recent progresses, only unidirectional conversion with efficiencies on the order of 10
−5
has been realized. In this article, we demonstrate the bidirectional electro-optic conversion in TFLN-superconductor hybrid system, with conversion efficiency improved by more than three orders of magnitude. Our air-clad device architecture boosts the sustainable intracavity pump power at cryogenic temperatures by suppressing the prominent photorefractive effect that limits cryogenic performance of TFLN, and reaches an efficiency of 1.02% (internal efficiency of 15.2%). This work firmly establishes the TFLN-superconductor hybrid EO system as a highly competitive transduction platform for future quantum network applications.
Coherent conversion between optical and microwave photonics is needed for future quantum applications. Here, the authors combine thin-film lithium niobate and superconductor platforms as a hybrid electro-optic system to achieve high-efficiency frequency conversion between microwave and optical modes.