Nagai Yusuke, Shao-Chieh Chen, Kajikawa Kotaro
Appl Opt. 2017 Nov 10;56(32):8969-8972. doi: 10.1364/AO.56.008969.
A random laser of a photonic crystal fiber (PCF) with holes filled with laser dye-doped nematic liquid crystal (NLC) is reported. When the excitation polarization was along the PCF axis, the measured laser threshold was 80 μJ/mm per pulse, which is much lower than the previously reported random laser of PCF filled with laser dye-doped organic solvent. This low threshold is due to the high refractive index of the NLC, which produces a greater scattering efficiency. In contrast, when the excitation polarization is perpendicular to the PCF axis, the threshold was much higher or the laser oscillation was absent. This is because of the lower refractive index of the NLC for the perpendicular polarization. The laser oscillation was absent in the isotropic phase because of a low fluorescence efficiency at high temperatures.
报道了一种光子晶体光纤（PCF）随机激光器，其纤芯中的孔填充了掺杂激光染料的向列型液晶（NLC）。当激发偏振沿光子晶体光纤轴时，测得的激光阈值为每脉冲80 μJ/mm，这远低于先前报道的填充有掺杂激光染料的有机溶剂的光子晶体光纤随机激光器。这种低阈值归因于向列型液晶的高折射率，其产生了更高的散射效率。相反，当激发偏振垂直于光子晶体光纤轴时，阈值要高得多或不存在激光振荡。这是因为向列型液晶对于垂直偏振具有较低的折射率。在各向同性相中不存在激光振荡，这是由于高温下荧光效率较低。
