Random lasing and weak localization of light in dye-doped nematic liquid crystals
Random lasing and weak localization of light in dye-doped nematic liquid crystals
复制标题
DOI：
10.1364/oe.14.007737
复制
发表时间：
2006-08-21
期刊：
影响因子：
3.8
通讯作者：
Bartolino, R.
中科院分区：
文献类型：
--
作者：
Strangi, G.;Ferjani, S.;Bartolino, R.
报道了在具有长程介电张量涨落的部分有序光学各向异性液晶中首次观察到的随机激光作用。在给定的泵浦功率以上，荧光曲线塌陷，并且典型的窄化和爆炸效应导致离散的尖峰。周期性多重散射中的干涉效应的意外幸存为向列相激光提供了所需的光反馈。光波在取向有序液晶中的相干后向散射表现出弱的光局域化，这有力地支持了增益介质存在下的扩散激光作用。散斑状发射模式的强度起伏表明了扩散激光发射的典型时空随机性。比较了激光对不同有序度的半导体粉末、自有序胆甾相和部分有序胆甾相液晶的作用。(c)2006年美国光学学会。
The first observation of random laser action in a partially ordered, optically anisotropic nematic liquid crystal with long-range dielectric tensor fluctuations is reported. Above a given pump power the fluorescence curve collapses and the typical narrowing and explosion effect leads to discrete sharp peaks. The unexpected surviving of interference effects in recurrent multiple scattering provide the required optical feedback for lasing in nematics. Coherent backscattering of light waves in orientationally ordered nematic liquid crystals manifests a weak localization of light which strongly supports diffusive laser action in presence of gain medium. Intensity fluctuations of the speckle-like emission pattern indicate the typical spatio-temporal randomness of diffusive laser emission. A comparison of the laser action is reported for systems with different order degree: fully disordered semiconductor powders, self-ordered cholesterics and partially ordered nematic liquid crystals. (c) 2006 Optical Society of America.