{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,8,17]],"date-time":"2026-08-17T12:28:05Z","timestamp":1786969685586,"version":"build-2736575974"},"reference-count":27,"publisher":"Springer Science and Business Media LLC","issue":"1","license":[{"start":{"date-parts":[[2026,6,4]],"date-time":"2026-06-04T00:00:00Z","timestamp":1780531200000},"content-version":"tdm","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0"},{"start":{"date-parts":[[2026,8,17]],"date-time":"2026-08-17T00:00:00Z","timestamp":1786924800000},"content-version":"vor","delay-in-days":74,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0"}],"funder":[{"DOI":"10.13039\/501100000780","name":"European Commission","doi-asserted-by":"publisher","award":["MAGNIFIC (Grant 101091968)"],"award-info":[{"award-number":["MAGNIFIC (Grant 101091968)"]}],"id":[{"id":"10.13039\/501100000780","id-type":"DOI","asserted-by":"publisher"}]},{"DOI":"10.13039\/501100011033","name":"Agencia Estatal de Investigaci\u00f3n","doi-asserted-by":"publisher","award":["PID2021-124618NB-C21,"],"award-info":[{"award-number":["PID2021-124618NB-C21,"]}],"id":[{"id":"10.13039\/501100011033","id-type":"DOI","asserted-by":"publisher"}]}],"content-domain":{"domain":["link.springer.com"],"crossmark-restriction":false},"short-container-title":["Sci Rep"],"abstract":"<jats:title>Abstract<\/jats:title>\n                  <jats:p>Optomechanical crystal cavities (OMCCs) display appealing features to function as on-chip photonic microwave oscillators (PMOs) when operated in the phonon lasing regime. Silicon OMCCs have so far demonstrated the best performance in terms of phase noise in a free-running configuration. Some preliminary experiments have also demonstrated that the generated microwave tone can be used for mixing wireless signals compliant with 5G standards. Still, more research is needed to identify the primary noise sources and determine the path towards improvement. Here, we report experiments on the realization of optomechanical PMOs operating at 4 GHz under two different driving conditions of the cavity: light coupling via a tapered fiber loop versus using an adjacent integrated waveguide illuminated by a lensed fiber. We performed measurements of the phase noise and the frequency stability in time of the detected tone for both cases and observed an improvement when the light is coupled by an adjacent integrated waveguide. This can be explained by the fact that the ambient-induced motion and changes due to perturbations in the refractive index of the medium surrounding the fiber loop result in variations of the coupling, which in turn affect the stability of the PMO. These results emphasize the relevance of a mechanically stable coupling technique when using such optomechanical devices in real applications, which can be of particular importance in environments where large vibrations are expected.<\/jats:p>","DOI":"10.1038\/s41598-026-55778-1","type":"journal-article","created":{"date-parts":[[2026,6,4]],"date-time":"2026-06-04T17:46:14Z","timestamp":1780595174000},"update-policy":"https:\/\/doi.org\/10.1007\/springer_crossmark_policy","source":"Crossref","is-referenced-by-count":0,"title":["Phase-noise and stability comparison of fiber-loop and integrated-waveguide coupling in optomechanical crystal oscillators"],"prefix":"10.1038","volume":"16","author":[{"given":"Ra\u00fal","family":"Ortiz","sequence":"first","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Xinyan","family":"Yang","sequence":"additional","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Alejandro","family":"Mart\u00ednez","sequence":"additional","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Laura","family":"Mercad\u00e9","sequence":"additional","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]}],"member":"297","published-online":{"date-parts":[[2026,6,4]]},"reference":[{"key":"55778_CR1","doi-asserted-by":"publisher","first-page":"728","DOI":"10.1038\/nphoton.2011.293","volume":"5","author":"L Maleki","year":"2011","unstructured":"Maleki, L. The optoelectronic oscillator. Nat. Photonics 5, 728\u2013730. https:\/\/doi.org\/10.1038\/nphoton.2011.293 (2011).","journal-title":"Nat. Photonics"},{"key":"55778_CR2","doi-asserted-by":"publisher","first-page":"486","DOI":"10.1038\/s41566-020-0617-x","volume":"14","author":"J Liu","year":"2020","unstructured":"Liu, J. et al. Photonic microwave generation in the X- and K-band using integrated soliton microcombs. Nat. Photonics 14, 486\u2013491. https:\/\/doi.org\/10.1038\/s41566-020-0617-x (2020).","journal-title":"Nat. Photonics"},{"key":"55778_CR3","doi-asserted-by":"publisher","first-page":"534","DOI":"10.1038\/s41586-024-07058-z","volume":"627","author":"I Kudelin","year":"2024","unstructured":"Kudelin, I. et al. Photonic chip-based low-noise microwave oscillator. Nature 627, 534\u2013539. https:\/\/doi.org\/10.1038\/s41586-024-07058-z (2024).","journal-title":"Nature"},{"key":"55778_CR4","doi-asserted-by":"publisher","first-page":"540","DOI":"10.1038\/s41586-024-07057-0","volume":"627","author":"S Sun","year":"2024","unstructured":"Sun, S. et al. Integrated optical frequency division for microwave and mmWave generation. Nature 627, 540\u2013545. https:\/\/doi.org\/10.1038\/s41586-024-07057-0 (2024).","journal-title":"Nature"},{"key":"55778_CR5","doi-asserted-by":"publisher","first-page":"546","DOI":"10.1038\/s41586-024-07136-2","volume":"627","author":"Y Zhao","year":"2024","unstructured":"Zhao, Y. et al. All-optical frequency division on-chip using a single laser. Nature 627, 546\u2013552. https:\/\/doi.org\/10.1038\/s41586-024-07136-2 (2024).","journal-title":"Nature"},{"key":"55778_CR6","doi-asserted-by":"publisher","DOI":"10.1038\/s41377-025-01795-0","volume":"14","author":"W Sun","year":"2025","unstructured":"Sun, W. et al. A chip-integrated comb-based microwave oscillator. Light Sci. Appl. 14, 179. https:\/\/doi.org\/10.1038\/s41377-025-01795-0 (2025).","journal-title":"Light Sci. Appl."},{"key":"55778_CR7","doi-asserted-by":"publisher","first-page":"78","DOI":"10.1038\/nature08524","volume":"462","author":"M Eichenfield","year":"2009","unstructured":"Eichenfield, M., Chan, J., Camacho, R. M., Vahala, K. J. & Painter, O. Optomechanical crystals. Nature 462, 78\u201382. https:\/\/doi.org\/10.1038\/nature08524 (2009).","journal-title":"Nature"},{"key":"55778_CR8","doi-asserted-by":"publisher","first-page":"413","DOI":"10.1515\/nanoph-2014-0004","volume":"3","author":"Y Pennec","year":"2014","unstructured":"Pennec, Y. et al. Modeling light-sound interaction in nanoscale cavities and waveguides. Nanophotonics 3, 413\u2013440. https:\/\/doi.org\/10.1515\/nanoph-2014-0004 (2014).","journal-title":"Nanophotonics"},{"key":"55778_CR9","doi-asserted-by":"publisher","first-page":"3535","DOI":"10.1515\/nanoph-2020-0148","volume":"9","author":"L Mercad\u00e9","year":"2020","unstructured":"Mercad\u00e9, L., Mart\u00edn, L. L., Griol, A., Navarro-Urrios, D. & Mart\u00ednez, A. Microwave oscillator and frequency comb in a silicon optomechanical cavity with a full phononic bandgap. Nanophotonics 9, 3535\u20133544. https:\/\/doi.org\/10.1515\/nanoph-2020-0148 (2020).","journal-title":"Nanophotonics"},{"key":"55778_CR10","doi-asserted-by":"publisher","DOI":"10.1063\/1.5121774","volume":"4","author":"I Ghorbel","year":"2019","unstructured":"Ghorbel, I. et al. Optomechanical gigahertz oscillator made of a two photon absorption free piezoelectric III\/V semiconductor. APL Photonics 4, 116103. https:\/\/doi.org\/10.1063\/1.5121774 (2019).","journal-title":"APL Photonics"},{"key":"55778_CR11","doi-asserted-by":"publisher","first-page":"2540","DOI":"10.1021\/acsphotonics.3c00074","volume":"10","author":"R Horv\u00e1th","year":"2023","unstructured":"Horv\u00e1th, R. et al. Sub-Hz closed-loop electro-optomechanical oscillator with Gallium Phosphide photonic crystal integrated on SoI circuitry. ACS Photonics 10, 2540\u20132548. https:\/\/doi.org\/10.1021\/acsphotonics.3c00074 (2023).","journal-title":"ACS Photonics"},{"key":"55778_CR12","doi-asserted-by":"publisher","DOI":"10.1038\/s41467-021-25884-x","volume":"12","author":"CC Rodrigues","year":"2021","unstructured":"Rodrigues, C. C. et al. Optomechanical synchronization across multi-octave frequency spans. Nat. Commun. 12, 5625. https:\/\/doi.org\/10.1038\/s41467-021-25884-x (2021).","journal-title":"Nat. Commun."},{"key":"55778_CR13","doi-asserted-by":"publisher","DOI":"10.1126\/sciadv.ady4167","volume":"11","author":"M Asano","year":"2025","unstructured":"Asano, M., Okamoto, H. & Yamaguchi, H. Synthesized Kuramoto potential via optomechanical Floquet engineering. Sci. Adv. 11, eady4167. https:\/\/doi.org\/10.1126\/sciadv.ady4167 (2025).","journal-title":"Sci. Adv."},{"key":"55778_CR14","doi-asserted-by":"publisher","DOI":"10.1002\/lpor.202100175","volume":"15","author":"L Mercad\u00e9","year":"2021","unstructured":"Mercad\u00e9, L., Morant, M., Griol, A., Llorente, R. & Mart\u00ednez, A. Photonic frequency conversion of OFDM microwave signals in a wavelength-scale optomechanical cavity. Laser Photonics Rev. 15, 2100175. https:\/\/doi.org\/10.1002\/lpor.202100175 (2021).","journal-title":"Laser Photonics Rev."},{"key":"55778_CR15","doi-asserted-by":"publisher","first-page":"6825","DOI":"10.1364\/JLT.42.006825","volume":"42","author":"V Fito","year":"2024","unstructured":"Fito, V. et al. Experimental Evaluation of All-Optical Up- and Down-Conversion of 3GPP 5G NR Signals Using an Optomechanical Crystal Cavity Frequency Comb. Journal of Lightwave Technology 42, 6825\u20136831. https:\/\/doi.org\/10.1364\/JLT.42.006825 (2024).","journal-title":"Journal of Lightwave Technology"},{"key":"55778_CR16","doi-asserted-by":"publisher","DOI":"10.1103\/PhysRevA.74.023813","volume":"74","author":"M Hossein-Zadeh","year":"2006","unstructured":"Hossein-Zadeh, M., Rokhsari, H., Hajimiri, A. & Vahala, K. J. Characterization of a radiation-pressure-driven micromechanical oscillator. Phys. Rev. A 74, 023813. https:\/\/doi.org\/10.1103\/PhysRevA.74.023813 (2006).","journal-title":"Phys. Rev. A"},{"key":"55778_CR17","doi-asserted-by":"publisher","DOI":"10.1103\/ht9f-v428","volume":"7","author":"R Ortiz","year":"2025","unstructured":"Ortiz, R., Mart\u00ednez, A., Arab\u00ed, C. M. & Mili\u00e1n, C. Dual-mode phonon dynamics and lasing in optomechanical cavities. Phys. Rev. Res. 7, 043109. https:\/\/doi.org\/10.1103\/ht9f-v428 (2025).","journal-title":"Phys. Rev. Res."},{"key":"55778_CR18","doi-asserted-by":"publisher","DOI":"10.1103\/PhysRevLett.127.073601","volume":"127","author":"L Mercad\u00e9","year":"2021","unstructured":"Mercad\u00e9, L. et al. Floquet phonon lasing in multimode optomechanical systems. Phys. Rev. Lett. 127, 073601. https:\/\/doi.org\/10.1103\/PhysRevLett.127.073601 (2021).","journal-title":"Phys. Rev. Lett."},{"key":"55778_CR19","doi-asserted-by":"publisher","first-page":"1391","DOI":"10.1103\/RevModPhys.86.1391","volume":"86","author":"M Aspelmeyer","year":"2014","unstructured":"Aspelmeyer, M., Kippenberg, T. J. & Marquardt, F. Cavity optomechanics. Rev. Mod. Phys. 86, 1391\u20131452. https:\/\/doi.org\/10.1103\/RevModPhys.86.1391 (2014).","journal-title":"Rev. Mod. Phys."},{"key":"55778_CR20","doi-asserted-by":"publisher","DOI":"10.1038\/ncomms5452","volume":"5","author":"J Gomis-Bresco","year":"2014","unstructured":"Gomis-Bresco, J. et al. A one-dimensional optomechanical crystal with a complete phononic band gap. Nat. Commun. 5, 4452. https:\/\/doi.org\/10.1038\/ncomms5452 (2014).","journal-title":"Nat. Commun."},{"key":"55778_CR21","doi-asserted-by":"publisher","first-page":"480","DOI":"10.1038\/nature07545","volume":"456","author":"M Li","year":"2008","unstructured":"Li, M. et al. Harnessing optical forces in integrated photonic circuits. Nature 456, 480\u2013484. https:\/\/doi.org\/10.1038\/nature07545 (2008).","journal-title":"Nature"},{"key":"55778_CR22","doi-asserted-by":"publisher","DOI":"10.1063\/1.4826924","volume":"103","author":"S Gr\u00f6blacher","year":"2013","unstructured":"Gr\u00f6blacher, S., Hill, J. T., Safavi-Naeini, A. H., Chan, J. & Painter, O. Highly efficient coupling from an optical fiber to a nanoscale silicon optomechanical cavity. Applied Physics Letters 103, 181104. https:\/\/doi.org\/10.1063\/1.4826924 (2013).","journal-title":"Applied Physics Letters"},{"key":"55778_CR23","doi-asserted-by":"publisher","DOI":"10.1103\/PhysRevA.90.023825","volume":"90","author":"KY Fong","year":"2014","unstructured":"Fong, K. Y., Poot, M., Han, X. & Tang, H. X. Phase noise of self-sustained optomechanical oscillators. Phys. Rev. A 90, 023825. https:\/\/doi.org\/10.1103\/PhysRevA.90.023825 (2014).","journal-title":"Phys. Rev. A"},{"key":"55778_CR24","doi-asserted-by":"publisher","first-page":"24522","DOI":"10.1364\/OE.19.024522","volume":"19","author":"S Tallur","year":"2011","unstructured":"Tallur, S., Sridaran, S. & Bhave, S. A. A monolithic radiation-pressure driven, low phase noise silicon nitride opto-mechanical oscillator. Opt. Express 19, 24522\u201324529. https:\/\/doi.org\/10.1364\/OE.19.024522 (2011).","journal-title":"Opt. Express"},{"key":"55778_CR25","doi-asserted-by":"publisher","DOI":"10.1017\/CBO9780511812798","volume-title":"Phase Noise and Frequency Stability in Oscillators","author":"E Rubiola","year":"2008","unstructured":"Rubiola, E. Phase Noise and Frequency Stability in Oscillators (The Cambridge RF and Microwave Engineering Series (Cambridge University Press, 2008)."},{"key":"55778_CR26","doi-asserted-by":"publisher","DOI":"10.1063\/1.4801473","volume":"102","author":"J Zheng","year":"2013","unstructured":"Zheng, J. et al. Feedback and harmonic locking of slot-type optomechanical oscillators to external low-noise reference clocks. Appl. Phys. Lett. 102, 141117. https:\/\/doi.org\/10.1063\/1.4801473 (2013).","journal-title":"Appl. Phys. Lett."},{"key":"55778_CR27","doi-asserted-by":"publisher","DOI":"10.1038\/srep06842","volume":"4","author":"X Luan","year":"2014","unstructured":"Luan, X. et al. An integrated low phase noise radiation-pressure-driven optomechanical oscillator chipset. Sci. Rep. 4, 6842. https:\/\/doi.org\/10.1038\/srep06842 (2014).","journal-title":"Sci. Rep."}],"container-title":["Scientific Reports"],"original-title":[],"language":"en","link":[{"URL":"https:\/\/www.nature.com\/articles\/s41598-026-55778-1","content-type":"text\/html","content-version":"vor","intended-application":"text-mining"},{"URL":"https:\/\/www.nature.com\/articles\/s41598-026-55778-1.pdf","content-type":"application\/pdf","content-version":"vor","intended-application":"text-mining"},{"URL":"https:\/\/www.nature.com\/articles\/s41598-026-55778-1.pdf","content-type":"application\/pdf","content-version":"vor","intended-application":"similarity-checking"}],"deposited":{"date-parts":[[2026,8,17]],"date-time":"2026-08-17T12:03:45Z","timestamp":1786968225000},"score":1,"resource":{"primary":{"URL":"https:\/\/www.nature.com\/articles\/s41598-026-55778-1"}},"subtitle":[],"short-title":[],"issued":{"date-parts":[[2026,6,4]]},"references-count":27,"journal-issue":{"issue":"1","published-online":{"date-parts":[[2026,12]]}},"alternative-id":["55778"],"URL":"https:\/\/doi.org\/10.1038\/s41598-026-55778-1","relation":{},"ISSN":["2045-2322"],"issn-type":[{"value":"2045-2322","type":"electronic"}],"subject":[],"published":{"date-parts":[[2026,6,4]]},"assertion":[{"value":"12 January 2026","order":1,"name":"received","label":"Received","group":{"name":"ArticleHistory","label":"Article History"}},{"value":"27 May 2026","order":2,"name":"accepted","label":"Accepted","group":{"name":"ArticleHistory","label":"Article History"}},{"value":"4 June 2026","order":3,"name":"first_online","label":"First Online","group":{"name":"ArticleHistory","label":"Article History"}},{"value":"The authors declare no competing interests.","order":1,"name":"Ethics","label":"Competing interests","group":{"name":"EthicsHeading","label":"Declarations"}}],"article-number":"25622"}}