基于被动锁模光纤激光器中色散波与孤子波的相互干涉产生的光谱边带效应,提出了一种测量单模光纤色散系数的方法。测量了各级边带中心波长的偏移量,利用边带偏移量与腔内总色散之间的关系,得到腔内总色散值。不同长度的同种光纤构成的环形腔,其总色散值不同,它与光纤长度的变化斜率即是待测光纤的色散系数。搭建了被动锁模掺铒光纤激光器平台,在1560 nm波段测量了G.652常规单模光纤的色散系数,实验值为16 ps/(nm·km),与典型值17 ps/(nm·km)符合得很好。

Based on the sideband spectrum produced by the interference of dispersion wave and solition wave in the passively mode-locked fiber laser. The wavelength offset from the central wavelength in the sideband spectrum is measured, the total cavity dispersion is obtained with the relation between the sideband offset and the total cavity dispersion. Ring cavities with different lengths of the same type fibers have different dispersions. The slope of the variation of dispersions corresponding to the fiber length is the dispersion coefficient to be measured. The platform of a passively mode-locked fiber laser is built, and the dispersion coefficient of G.652 fiber has been measured, whose experimental value is 16 ps/(nm·km) that is agrees well with the conventional value of 17 ps/(nm·km).