石英光子晶体光纤中高功率中红外超连续谱的产生

High Power Mid-infrared Supercontinuum Generation in Silica Photonic Crystal Fiber

非石英光纤在产生大功率超连续谱方面存在难以克服的局限性。本文首次报道了采用石英光纤产生大功率中红外超连续谱。精心设计光纤结构使色散有利于超连续谱向中红外波段展宽,同时保证相对较大的芯径以承受较高的泵浦功率。合理选择光纤长度,在保证光谱展宽到3.4μm的情况下使光纤损耗的影响降低到最小限度。研究表明,在1.95μm皮秒脉冲泵浦下,采用色散适宜的石英光子晶体光纤可以产生20d B带宽覆盖1 550~3 420 nm的超连续谱。超连续谱的平均功率可达56.6 W。

Non-silica fibers have the intrinsic limitations in high power supercontinuum generation.High power mid-infrared supercontinuum generation in silica photonic crystal fiber is firstly investigated in our studies. The dispersion of fiber is designed to be beneficial to supercontinuum broadening to mid-infrared region. Meanwhile,to withstand high pumping power,a relatively large core diameter is essential. On the premise of supercontinuum broadening to 3. 4 μm,fiber length is optimized to reduce the loss of the optical fibers. The results show that it is feasible to generate supercontinuum spectrum with 20 d B-bandwidth covering from 1 550 nm to 3 420 nm by injecting 1. 95 μm picosecond pulse into silica photonic crystal fiber with appropriate dispersion. The average power of the supercontinuum spectrum can reach 56. 6 W.