Tunable liquid crystal optical microcavities
Tunable liquid crystal optical microcavities
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DOI：
10.1117/12.874688
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发表时间：
2011-02
期刊：
影响因子：
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通讯作者：
Igor Muševič;M. Humar
中科院分区：
文献类型：
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作者：
Igor Muševič;M. Humar
在这项工作中，我们证明向列液晶液滴可以用作低损耗和高度可调的回音壁模式（WGM）光学微腔。它们是通过将液晶与不混溶的液体混合而自发形成的。光学模式可以通过施加电场、改变温度或通过机械变形来调节。对于 17 μm 直径液滴中约 600 nm WGM，电场的调谐范围在 2.6 V/μm 时高达 20 nm。调谐速度快且几乎与所施加的电压呈线性关系。在温度调节的情况下，我们可以在 30 K 的温度变化下将模式移动超过 15 nm。此外，我们还可以对包含液晶滴的 PDMS 聚合物的自立式薄膜应用机械变形。在 15% 应变下，模移超过 30 nm。在所有三种情况下，调谐都超出了谐振器的自由光谱范围，并且是完全可逆的。
In this work we show that nematic liquid-crystal droplets can be used as low-loss and highly tunable whisperinggallery mode (WGM) optical microcavities. They are spontaneously formed by mixing the liquid crystal with an immiscible liquid. The optical modes can be tuned either by applying an electric field, changing the temperature or by mechanical deformation. The tuning range for the electric field is as high as 20 nm at 2.6 V/μm for a ~ 600 nm WGM in 17 μm diameter droplets. Tuning is fast and almost linear with the applied voltage. In the case of the temperature tuning, we can shift the modes by more than 15 nm at a temperature change of 30 K. Further, we can also apply mechanical deformation to a free standing film of PDMS polymer containing the liquid crystal droplets. At 15% strain the mode shift is more than 30 nm. In all the three cases the tuning exceeds the free spectral range of the resonators and is completely reversible.