Optical properties of laser lines and fluorescent spectrum in cholesteric liquid crystal laser
- 주제(키워드) Cholesteric liquid crystal laser , Fluorescence enhancement , Fluorescence spectrum control , Optical properties of the laser lines
- 등재 SCIE, SCOPUS
- 발행기관 American Scientific Publishers
- 발행년도 2015
- 총서유형 Journal
- URI http://www.dcollection.net/handler/ewha/000000120460
- 본문언어 영어
- Published As http://dx.doi.org/10.1166/jnn.2015.11176
- 저작권 이화여자대학교 논문은 저작권에 의해 보호받습니다.
초록/요약
We experimentally studied the comprehensive optical properties of the laser lines and fluorescent spectrum generated by a continuous tunable cholesteric liquid crystal (CLC) laser array. We found that the laser lines generated from a CLC with a right-handed circular helix were right-handed circular polarized and laser lines generated from a CLC with a left-handed circular helix were left-handed circular polarized. Inside the photonic band gap, the CLC structure with right-(left-) handed helicity suppressed the fluorescence generated with right (left) circular polarized light, and instead the suppressed right (left) circular polarized light energy moved to the outside of the photonic band gap, so we can say that the fluorescence intensity outside of the photonic band gap is enhanced with right (left) handed circular polarized light. Depending on the position of the photonic band gap, the fluorescence quantum yield value increased by up to ∼15%. These enhanced fluorescence intensities at the PBG edge will evolve into lasing at the upper lasing threshold. It is particularly interesting to see that the fluorescence intensity and shape could be controlled by adjusting the external geometrical factor of the photonic band gaps. The lasing threshold of the CLC lasers was in the range of 1.5-5.3 μJ/pulse. For CLC laser device applications, it is necessary and essential to know the optical properties of the generated laser lines and of the fluorescence spectrum. Copyright © 2015 American Scientific Publishers All rights reserved.
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