Jiao Kai, Yao Jinmei, Zhao Zheming, Wang Xiange, Si Nian, Wang Xunsi, Chen Peng, Xue Zugang, Tian Youmei, Zhang Bin, Zhang Peiqing, Dai Shixun, Nie Qiuhua, Wang Rongping
Opt Express. 2019 Feb 4;27(3):2036-2043. doi: 10.1364/OE.27.002036.
We have prepared a well-structured tellurium chalcogenide (ChG) fiber with a specialized double cladding structure by an improved extrusion method, and experimentally demonstrated an ultra-flat mid-infrared (MIR) supercontinuum (SC) generation in such a fiber. The step-index fiber had an optical loss of <1 dB/m in a range from 7.4 to 9.7 μm with a minimum loss of 0.69 dB/m at 7.87 μm. Simulation showed that an all-normal dispersion profile can be realized in this double cladding tellurium fiber. An ultra-flat MIR SC spectrum (3.2-12.1μm at -10 dB, ~2-14 μm at -30 dB) was generated from a 22-cm long fiber pumped with a femtosecond laser at 5 μm (150 fs, 1 kHz). Then the degree of coherence was calculated out based on a simulation, showing that a high coherent MIR SC (from 2.9 to 13.1 μm) can be generated in this double-cladding tellurium fiber.
我们通过改进的挤压方法制备了一种结构良好的碲硫属化物（ChG）光纤，其具有特殊的双包层结构，并通过实验证明了在这种光纤中能产生超平坦的中红外（MIR）超连续谱（SC）。该阶跃折射率光纤在7.4至9.7μm范围内的光损耗<1dB/m，在7.87μm处的最小损耗为0.69dB/m。模拟表明，这种双包层碲光纤可以实现全正色散分布。用5μm的飞秒激光（~150fs，1kHz）泵浦一根22cm长的光纤，产生了超平坦的中红外超连续谱（在-10dB时约为3.2 - 12.1μm，在-30dB时约为2 - 14μm）。然后通过模拟计算出了相干度，表明在这种双包层碲光纤中可以产生高相干的中红外超连续谱（从2.9至13.1μm）。
