Article abstract

Nature Photonics 3, 595 - 600 (2009)
Published online: 27 September 2009 | doi:10.1038/nphoton.2009.170

Subject Category: Novel materials and engineered structures

Electrically tunable liquid crystal optical microresonators

M. Humar1, M. Ravnik2, S. Pajk3 & I. Mus caronevic caron1,2

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 microm-1 for a approx600 nm WGM in 17-microm-diameter droplets and high Q-factors up to approx12,000 in 33-microm-diameter droplets. The tunability is approximately two orders of magnitude larger than usually achieved in solid-state microresonators.

  1. J. Stefan Institute, Jamova 39, SI-1000, Ljubljana, Slovenia
  2. Faculty of Mathematics and Physics, University of Ljubljana, Jadranska 19, SI-1000, Ljubljana, Slovenia
  3. Faculty of Pharmacy, University of Ljubljana, As caronkerc caroneva 7, SI-1000, Ljubljana, Slovenia

Correspondence to: I. Mus caronevic caron1,2 e-mail:


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