在搭建的窄瞬时线宽的扫频激光光源的基础上，通过实验和数值模型对影响激光瞬时线宽的主要因素进行了研究。研究结果发现，扫频激光的瞬时线宽会随着色散的增加而变宽，滤波器的带宽和加载给滤波器的信号都会影响瞬时线宽，同时腔内的模式竞争能够保证更窄的激光瞬时线宽。

Based on the homemade frequency-swept laser source with a narrow instantaneous line width, the main factors influencing the laser instantaneous line width are investigated by numerical model and experiment. The research results indicate that the instantaneous line width of the frequency-swept laser increases with the increment of dispersion, and the filter bandwidth and the signal pattern loaded to the filter both influence the instantaneous line width. At the same time, the intra-cavity mode competition can ensure a narrower instantaneous laser line width.