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Fabrication of Silica Ultra High Quality Factor Microresonators
Published on: July 2, 2012
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Fundamental limits in high-Q droplet microresonators
A Giorgini1, S Avino1, P Malara1
1Consiglio Nazionale delle Ricerche, Istituto Nazionale di Ottica (INO), via Campi Flegrei 34, Complesso "A. Olivetti", 80078 Pozzuoli (Napoli), Italy.
Scientific Reports
|February 8, 2017
Summary
Liquid droplet microresonators show potential for sensitive liquid spectroscopy. Capillary fluctuations enhance light coupling, enabling ultra-sensitive measurements of transparent liquids in nano-liter volumes.
Area of Science:
- Optics and Photonics
- Materials Science
- Physical Chemistry
Background:
- Whispering-gallery-mode microresonators offer advanced sensing and photonic device capabilities.
- Theoretical models predict thermal surface distortions and capillary waves significantly impact droplet optical quality factors at visible wavelengths.
Purpose of the Study:
- To experimentally investigate the theoretical predictions of thermal surface distortions and capillary waves on liquid droplet microresonators.
- To measure the optical quality factor and photon lifetime in liquid droplet microresonators.
Main Methods:
- Utilized transient cavity ring-down spectroscopy for precise optical measurements.
- Employed ultra-short light-cavity interaction times to isolate intrinsic losses and avoid external perturbations (thermal, acoustic, laser-frequency noise).
Main Results:
- Observed photon lifetimes at least ten times longer than theoretically predicted thermal limits.
- Demonstrated that capillary fluctuations activate surface scattering, which is crucial for light coupling into the microresonator.
Conclusions:
- Liquid droplet microresonators are highly promising for ultra-sensitive spectroscopy of transparent liquid compounds.
- The findings suggest droplet microresonators are ideal optical platforms for analyzing nano-liter liquid volumes.
