Optical transduction and routing of microwave phonons in cavity-optomechanical circuits

• Published in: Nature photonics Vol. 10; no. 7; pp. 489 - 496
• Main Authors: Fang, Kejie, Matheny, Matthew H., Luan, Xingsheng, Painter, Oskar
• Format: Journal Article
• Language: English
• Published: London Nature Publishing Group UK 01.07.2016; Nature Publishing Group
• Subjects: 142/126; 147/135; 639/624/399/1099; 639/624/400/385; 639/624/400/482; 639/925/927/1021; Acoustic waveguides; Acoustics; Applied and Technical Physics; Circuits; Devices; Electrons; Holes; Information processing; Microwaves; Phonons; Photonics; Physics; Quantum Physics; Radiation; Signal processing; Signal transduction; Wave propagation; Waveguides; United States > US; California
• ISSN: 1749-4885; 1749-4893
• DOI: 10.1038/nphoton.2016.107

Going beyond the canonical cavity-optomechanical system consisting of a Fabry–Perot cavity with a movable end mirror, here we explore a new paradigm in which phononic crystal waveguides are used to wire together local cavity elements to form interacting microcircuits of photons and phonons. Single cavity-waveguide elements, fabricated in the device layer of a silicon-on-insulator microchip, are used to optically excite and detect C-band (∼6 GHz) microwave phonons propagating in phononic-bandgap-guided acoustic waveguides. Interconnecting a pair of optomechanical cavities via a phonon waveguide is then used to demonstrate a tunable delay and filter for microwave-over-optical signals in the 1,500 nm wavelength band. Finally, we realize a tight-binding form of mechanical coupling between distant optomechanical cavities, leading to direct phonon exchange without dissipation in the waveguide. These initial demonstrations indicate the potential of cavity-optomechanical circuits for performing coherent signal processing as well as for realizing new modalities of optical readout in distributed micromechanical sensors. Researchers demonstrate microwave phonon waveguide circuits and tunable delay and filter for microwave-photonics signals carried by 1,500 nm wavelength light.