Localization of light in an optical microcapillary introduced by a droplet

Hamidfar, Tabassom, Tokmakov, Kirill V., Mangan, Brian J., Windeler, Robert S., Dmitriev, Artemiy V., Vitullo, Dashiell L.P., Bianucci, Pablo and Sumetsky, Misha (2018). Localization of light in an optical microcapillary introduced by a droplet. Optica, 5 (4), pp. 382-388.

Abstract

Sensing with optical whispering gallery modes (WGMs) is a rapidly developing detection method in modern microfluidics research. This method explores the perturbations of spectra of WGMs propagating along the wall of an optical microcapillary to characterize the liquid medium inside it. Here we show that WGMs in a silica microcapillary can be fully localized (rather than perturbed) by evanescent coupling to a water droplet and, thus, form a high-quality-factor microresonator. The spectra of this resonator, measured with a microfiber translated along the capillary, present a hierarchy of resonances that allow us to determine the size of the droplet and variation of its length due to the evaporation. The resolution of our measurements of this variation equal to 4.5 nm is only limited by the resolution of the optical spectrum analyzer used. The discovered phenomenon of complete localization of light in liquid-filled optical microcapillaries suggests a new type of microfluidic photonic device as well as an ultraprecise method for microfluidic characterization.

Publication DOI:	https://doi.org/10.1364/OPTICA.5.000382
Divisions:	College of Engineering & Physical Sciences College of Engineering & Physical Sciences > Aston Institute of Photonics Technology (AIPT)
Funding Information:	Funding. Royal Society (WM130110); Horizon 2020 Framework Programme (H2020) (H2020-EU.1.3.3, 691011); Engineering and Physical Sciences Research Council (EPSRC) (EP/P006183/1). Acknowledgment. M. S. acknowledges the Royal Society Wolfson Research Merit Aw
Additional Information:	© 2018 OSA. Published by The Optical Society under the terms of the Creative Commons Attribution 4.0 License. Further distribution of this work must maintain attribution to the author(s) and the published article’s title, journal citation, and DOI. Funding: Horizon 2020 Framework Programme (H2020) (H2020‐EU.1.3.3, 691011), Engineering and Physical Sciences Research Council (EPSRC) (EP/P006183/1).
Uncontrolled Keywords:	Electronic, Optical and Magnetic Materials,Atomic and Molecular Physics, and Optics
Publication ISSN:	2334-2536
Last Modified:	29 Oct 2024 14:01
Date Deposited:	28 Feb 2018 12:25
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Related URLs:	http://www.scop ... tnerID=8YFLogxK (Scopus URL) https://www.osa ... =optica-5-4-382 (Publisher URL)
PURE Output Type:	Article
Published Date:	2018-03-29
Accepted Date:	2018-02-24
Authors:	Hamidfar, Tabassom Tokmakov, Kirill V. ( 0000-0002-2808-6593) Mangan, Brian J. Windeler, Robert S. Dmitriev, Artemiy V. Vitullo, Dashiell L.P. Bianucci, Pablo Sumetsky, Misha ( 0000-0001-7289-3547)