光子晶体光纤载体中液晶随机激光辐射行为

将向列相液晶TEB30A、手性剂S-811、激光染料PM597的混合物填充空芯光子晶体光纤中，以Nd: YAG倍频532 nm激光作为泵浦光源，测量激光辐射谱，研究了光子晶体光纤载体中的随机激光辐射行为。泵浦激光侧面入射，侧面出射随机激光波长范围为590~605 nm，半高全宽约为0.3 nm；辐射方向较广。泵浦光端面入射，端面出射随机激光波长范围为580~605 nm，半高全宽约为0.3 nm。加热样品至各向同性温度时，端面和侧面激光辐射被关断。由实验结果得出，光子晶体中随机激光辐射源于微孔中填充的染料掺杂液晶混合物。手性向列相液晶中光子传输平均自由程和液晶分子介电张量的涨落随温度的变化，是影响出射激光强度的主要因素。

Random laser radiation behavior of liquid crystal in photonic crystal fiber carrier

A hollow-core photonic-crystal fiber filled with a mixture of nematic liquid crystal TEB30A, chiral agent S-811 and laser dye PM597 was pumped by a frequency-doubled Nd:YAG laser with a wavelength of 532 nm. The laser emission spectra was measured and the random laser radiation behavior in the photonic-crystal fiber carrier was investigated. When side-pumping was applied to the fiber, the emitted random laser with a wider radiation direction from the side face had a wavelength range of 590?605 nm and an FWMH of 0.3 nm. When end-pumping was employed to the fiber, the emitted random laser from the end face had a wavelength range of 580?605 nm and an FWMH of 0.3 nm. After the sample was heated to the isotropic temperature, the laser emission with both pumping methods was shut down. The experimental results demonstrate that the dye doped liquid crystal mixture in the micropore induce the random laser emission in the photonic-crystal. The change in the mean free path of photon transport and the fluctuation of the dielectric tensor of chiral nematic liquid crystals with temperature are the main factors affecting the laser intensity.