Yuan Jinhui, Kang Zhe, Li Feng, Zhang Xianting, Mei Chao, Zhou Guiyao, Sang Xinzhu, Wu Qiang, Yan Binbin, Zhou Xian, Zhong Kangping, Wang Kuiru, Yu Chongxiu, Farrell Gerald, Lu Chao, Tam Hwa Yaw, Wai P K A
Opt Lett. 2017 Sep 15;42(18):3537-3540. doi: 10.1364/OL.42.003537.
In this Letter, we demonstrate experimentally for the first time, to the best of our knowledge, discrete ultraviolet (UV) wavelength generation by cascaded intermodal FWM when femtosecond pump pulses at 800 nm are launched into the deeply normal dispersion region of the fundamental guided mode of a multimode photonic crystal fiber (MPCF). For pump pulses at average input powers of P=450, 550, and 650 mW, the first anti-Stokes waves are generated at the visible wavelength of 538.1 nm through intermodal phase matching between the fundamental and second-order guided mode of the MPCF. The first anti-Stokes waves generated then serve as the secondary pump for the next intermodal FWM process. The second anti-Stokes waves in the form of the third-order guided mode are generated at the UV wavelength of 375.8 nm. The maximum output power is above 10 mW for P=650 mW. We also confirm that the influences of fiber bending and intermodal walk-offs on the cascaded intermodal FWM-based frequency conversion process are negligible.
在本信函中，据我们所知，我们首次通过实验证明，当将800纳米的飞秒泵浦脉冲注入多模光子晶体光纤（MPCF）基模的深度正常色散区域时，通过级联多模四波混频（FWM）可产生离散紫外（UV）波长。对于平均输入功率P = 450、550和650毫瓦的泵浦脉冲，通过MPCF基模与二阶导模之间的多模相位匹配，在538.1纳米的可见光波长处产生了首个反斯托克斯波。然后产生的首个反斯托克斯波作为下一个多模FWM过程的二次泵浦。以三阶导模形式存在的第二个反斯托克斯波在375.8纳米的紫外波长处产生。当P = 650毫瓦时，最大输出功率超过10毫瓦。我们还证实，光纤弯曲和多模走离对基于级联多模FWM的频率转换过程的影响可忽略不计。
