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arXiv · 2102.09516

Transformation cavities with a narrow refractive index profile

Jung-Wan Ryu·Jinhang Cho
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Abstract

Recently, gradient index cavities, or so-called transformation cavities, designed by conformal transformation optics have been studied to support resonant modes with both high Q-factors and emission directionality. We propose a new design method for transformation cavities to realize a narrower width of the refractive index profile, a great advantage in experimental implementations, without losing the benefits of conformal mapping. We study the resonant modes with both high Q-factor and directional emission in the newly designed transformation cavities, where the refractive index profile is 50 percent narrower than in previously proposed transformation cavities. By varying a system parameter with a fixed maximal value of the refractive index profile inside the cavity, the width of the refractive index profile narrows, the Q-factors become higher, and the near and far field patterns maintain their properties, namely conformal whispering gallery modes and bidirectional emission, respectively.

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Jung-Wan Ryu, Jinhang Cho. 2021-02-18. Transformation cavities with a narrow refractive index profile. https://doi.org/10.1364/ol.422529

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