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arXiv · 1609.08818

Fundamental thermal noise in droplet microresonators

Antonio Giorgini·Saverio Avino·Pietro Malara·Paolo De Natale·Gianluca Gagliardi
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Abstract

Liquid droplet whispering-gallery-mode microresonators open a new research frontier for optomechanics and photonic devices. At visible wavelengths, where most liquids are transparent, a major contribution to a droplet optical quality factor is expected theoretically from thermal surface distortions and capillary waves. Here, we investigate experimentally these predictions using transient cavity ring-down spectroscopy. In this way, the optical out-coupling and intrinsic loss are measured independently while any perturbation induced by thermal, acoustic and laser-frequency noise is avoided thanks to the ultra-short light-cavity interaction time. The measurements reveal a photon lifetime ten times longer than the thermal limit and suggest that capillary fluctuations activate surface scattering effects responsible for light coupling.

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Antonio Giorgini, Saverio Avino, Pietro Malara, Paolo De Natale, Gianluca Gagliardi. 2016-09-28. Fundamental thermal noise in droplet microresonators. https://arxiv.org/abs/1609.08818

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