Electrically tunable liquid crystal optical microresonators
Electrically tunable liquid crystal optical microresonators
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DOI：
10.1038/nphoton.2009.170
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发表时间：
2009-10-01
期刊：
影响因子：
35
通讯作者：
Musevic, I.
中科院分区：
文献类型：
--
作者：
Humar, M.;Ravnik, M.;Musevic, I.
光学微谐振腔具有模体积小、Q值高等优点，在激光光源、有源滤波器和全光开关等方面有着广泛的应用。特别令人感兴趣的是可调谐谐振器，其中可以实现通过尺寸、形状、温度或电场调谐谐振频率。在这里，我们展示了电可调，低损耗回音壁模式（WGM）谐振器的液晶微滴，嵌入在聚合物基体。谐振频率的偏移通过双折射液晶谐振器介质的电场诱导的结构畸变来实现。向列型液晶微谐振器在2.6V μ m（-1）下对于17 μ m直径的液滴中的类似于600 nm的WGM具有20 nm量级的大调谐范围，并且在33 μ m直径的液滴中具有高达类似于12，000的高Q因子。可调谐性比通常在固态微谐振器中实现的大大约两个数量级。
Because of their small mode volume and high Q-factors, optical microresonators are interesting for applications such as laser sources, active filters and all-optical switches. Especially interesting are tunable resonators, in which the resonance frequency tuning by size, shape, temperature or electric field can be achieved. Here we demonstrate electrically tunable, low-loss whispering-gallery-mode (WGM) resonators made of nematic liquid crystal droplets, embedded in a polymer matrix. The shift in resonant frequencies is achieved via electric field-induced structural distortion of the birefringent liquid crystal resonator medium. Nematic liquid crystal microresonators have a large tuning range of the order of 20 nm at 2.6 V mu m(-1) for a similar to 600 nm WGM in 17-mu m-diameter droplets and high Q-factors up to similar to 12,000 in 33-mu m-diameter droplets. The tunability is approximately two orders of magnitude larger than usually achieved in solid-state microresonators.