中文摘要：

利用Sagnac梳状滤波器,研究了环形腔掺镱光纤激光器（YDFL）在室温和77 K时的多波长振荡行为。结果表明,在室温和77 K时,掺镱光纤（YDF）均呈现明显的非均匀加宽效应,使得掺镱光纤激光器的起振波长数随抽运光功率的提高而增多。但在室温下,因均匀加宽效应强,掺镱光纤增益的非均匀加宽并不能补偿其内禀不平坦的增益谱,造成波长缺失现象,且当波长间隔减小至0.8 nm时,均匀加宽效应引起的波长竞争造成了多波长振荡的稳定性下降。而在77 K时,掺镱光纤非均匀加宽效应明显增强,在0.8 nm的波长间隔下,无波长缺失现象,将起振波长数增加到32个,且多波长振荡稳定。

英文摘要：

Multiwavelength oscillation of ytterbium-doped fiber ring laser is investigated with a Sagnac comb filter at room temperature and 77 K. The experimental results show that, at both room temperature and 77 K, the ytterbium-doped fiber （YDF） exhibits obviously inhomogeneous gain broadening, which results that the lasing line number of the laser increases with the increase of pump power. However, due to the homogeneous gain broadening of the YDF, the gain imhomogeneity of the YDF at room temperature is not strong enough to compensate the intrinsic unevenness of the YDF gain spectrum, leading to lasing wavelengths missing. Moreover, when the wavelength spacing decreases to 0.8 nm, the wavelength competition caused by the homogeneous gain broadening of the YDF decreases the stability of multiwavelength oscillations. At 77 K, however, the inhomogeneous gain broadening of the YDF becomes stronger. For a spacing of 0.8 nm, 32 stable lasing lines without any potential lasing wavelengths missing between neighboring wavelengths have been obtained.