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

Abstract

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 orders of magnitude lower than expected has been realized. In this article, we demonstrate the first bidirectional electro-optic conversion in TFLN-superconductor hybrid system, with conversion efficiency improved by more than three orders of magnitude. Our new 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.

Single-sideband microwave-to-optical conversion in high-Q ferrimagnetic microspheres

“…Therefore, it can greatly promote the detection based on the microwave, help to improve the resolution of radar, and maybe realize the quantum enhanced radar system [7]. Recently, such a microwave to optical transducer [6] has been demonstrated in optomechanics, electro-optic interaction, atoms and ions [8][9][10][11][12][13][14][15][16][17]. Among these approaches, optomagnonics based on magnon provide an alternative and attractive approach of the coherent microwave-tooptical conversion because of its great frequency tuning range and long coherence time [18][19][20][21][22][23][24].…”