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arXiv · 0903.3829

Whispering-gallery mode micro-kylix resonators

Mher Ghulinyan·Alessandro Pitanti·Georg Pucker·Lorenzo Pavesi
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Abstract

Owing to their ability to confine electromagnetic energy in ultrasmall dielectric volumes, micro-disk, ring and toroid resonators hold interest for both specific applications and fundamental investigations. Generally, contributions from various loss channels within these devices lead to limited spectral windows (Q-bands) where highest mode Q-factors manifest. Here we describe a strategy for tuning Q-bands using a new class of micro-resonators, named micro-kylix resonators, in which engineered stress within an initially flat disk results in either concave or convex devices. To shift the Q-band by 60nm towards short wavelengths in flat micro-disks a 50% diameter reduction is required, which causes severe radiative losses suppressing Q's. With a micro-kylix, we achieve similar tuning and even higher Q's by two orders of magnitude smaller diameter modification (0.4%). The phenomenon relies on geometry-induced smart interplay between modified dispersions of material absorption and radiative loss-related Q-factors. Micro-kylix devices can provide new functionalities and novel technological solutions for photonics and micro-resonator physics.

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Mher Ghulinyan, Alessandro Pitanti, Georg Pucker, Lorenzo Pavesi. 2009-03-23. Whispering-gallery mode micro-kylix resonators. https://doi.org/10.1364/oe.17.009434

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