利用光谱展宽演化监测系统,观察光纤出射光的偏振消光比与光谱展宽的相关性。通过测量、比较和分析三根拉锥光子晶体光纤的寿命,可知光纤纤芯中存在对抽运光的四光子吸收过程,验证了拉锥光子晶体光纤光谱展宽性能退化是由光纤纤芯中多光子吸收效应产生的色心缺陷导致的。提出改用低光子能量的光源以大幅减缓多光子吸收效应的方案,并通过实验证实了使用1040 nm波长的抽运光可以有效延长拉锥光子晶体光纤的光谱展宽寿命。

Herein, using a spectral broadening evolution testing setup, the relationship between the polarization-extinction ratio (PER) of the photonic crystal fiber (PCF) output light and spectral broadening evolution is observed. By measuring, comparing, and analyzing the lifetimes of the three tapered PCFs, we find that the tapered PCFs experience four-photon absorption processes at the pump light wavelength. The reason for the spectral broadening performance degradation of the tapered PCF is that the multiphoton absorption in the fiber core results in the color-center defect. A light source with low photon energy is proposed to reduce the multiphoton absorption. The experiment verifies that using the pump light with wavelength of 1040 nm can effectively prolong the spectral broadening lifetime of the tapered PCF.