Tunable light lasing in dye doped ferroelectric liquid crystals

本计画系致力于研究染料掺杂铁电液晶之雷射性质之调谐。由于铁电液晶的变形螺旋效应，铁电液晶呈现一维周期结构。在这种材料中掺杂的染料显示出在这种结构中的自发辐射的抑制。DHF电光效应对于光子晶体应用具有三个吸引人的特性：1）微秒范围内的快速响应时间（~100µs），2）相当强的光学各向异性（Δ n ~ 0.2），3）在施加电场下螺旋周期性的变化。因此，利用染料掺杂DHF混合物作为电调谐无反射镜激光材料是很有前景的。在本项目范围内，将制备具有强光学各向异性（Δ n ~ 0.2）的可见光和近红外范围内螺距的DHF材料，并掺杂激光染料（例如香豆素500、DCM、罗丹明590、Kiton Red 620）。将制造具有这些混合物的垂面排列的电池。该项目的任务是揭示DHF材料的发射光谱的参数对施加到细胞的电压、DHF混合物的性质和激发能量的依赖性。

This project is devoted to the investigation of the tuning of the lasing properties of dye doped ferroelectric liquid crystals. Ferroelectric liquid crystals represent themselves a 1D periodic structure due to the deformed helix ferroelectric liquid crystal effect (DHF). The dye doped in such materials show the inhibitation of spontaneous emission inside such structures. The DHF electrooptical effect has three attractive properties for photonic crystals applications: 1) fast response time laying in microseconds range (~100µs), 2) rather strong optical anisotrophy (delta n ~ 0.2), 3) variation of the helix periodicity under application of an electric field. Therefore, it looks perspective to utilize dye doped DHF mixtures as electrically tunable mirrorless lasing materials. In scope of this project, DHF materials with a helix pitch laying in the visible and near infrared range with strong optical anisotropy (delta n ~ 0.2) will be prepared and doped with laser dyes (e.g. Coumarin 500, DCM, Rhodamine 590, Kiton Red 620). Cells with homeotropic alignment of these mixtures will be fabricated. The task of the project is to reveal the dependence of the parameters of the emission spectra of the DHF materials on the voltage applied to the cells, the properties of the DHF mixtures and the excitation energy.