Coherent optical wavelength conversion via cavity optomechanics

• Published in: Nature communications Vol. 3; no. 1; p. 1196
• Main Authors: Hill, Jeff T., Safavi-Naeini, Amir H., Chan, Jasper, Painter, Oskar
• Format: Journal Article
• Language: English
• Published: London Nature Publishing Group UK 13.11.2012; Nature Publishing Group
• Subjects: 639/624/399/1098; 639/766/400/482; Humanities and Social Sciences; multidisciplinary; Science; Science (multidisciplinary)
• ISSN: 2041-1723; 2041-1723
• DOI: 10.1038/ncomms2201

Both classical and quantum systems utilize the interaction of light and matter across a wide range of energies. These systems are often not naturally compatible with one another and require a means of converting photons of dissimilar wavelengths to combine and exploit their different strengths. Here we theoretically propose and experimentally demonstrate coherent wavelength conversion of optical photons using photon–phonon translation in a cavity-optomechanical system. For an engineered silicon optomechanical crystal nanocavity supporting a 4-GHz localized phonon mode, optical signals in a 1.5 MHz bandwidth are coherently converted over a 11.2 THz frequency span between one cavity mode at wavelength 1,460 nm and a second cavity mode at 1,545 nm with a 93% internal (2% external) peak efficiency. The thermal- and quantum-limiting noise involved in the conversion process is also analysed, and in terms of an equivalent photon number signal level are found to correspond to an internal noise level of only 6 and 4 × 10 −3 quanta, respectively. Coherent conversion of photons from one wavelength to another is promising for future quantum communications technologies. By exploiting coupling between resonances in an optomechanical crystal nanocavity, Hill et al . demonstrate conversion between optical wavelength photons via a mechanical resonance.