搭建了一个中心波长为1340 nm、扫频速度为30 kHz的光纤型窄瞬时线宽扫频激光光源，光源相位和光强稳定性高，扫频范围为10 nm，半峰全宽为6 nm，瞬时线宽小于0.018 nm，输出平均光功率为9.1 mW。实验扫频激光光源在傅里叶域锁模技术的基础上，使用精密度为5578、窄透射窗口的法布里-珀罗滤波器(FFP-TF)作为调谐滤波器，以腔内增益介质的自发辐射为背景光，经过单模长光纤后，到达FFP-TF 并对腔内的激光进行调谐滤波，最后稳定地输出窄瞬时线宽的扫频激光。讨论了影响光源瞬时线宽的因素。搭建的窄瞬时线宽扫频激光光源具有极高的精密度和稳定性，可直接应用于对分辨率要求比较高的高速分子光谱学、分子吸收光谱学等领域。

An all- fiber 30 kHz repetition rate swept laser source at a center wavelength of 1340 nm with narrow instantaneous linewidth is built for swept source optical coherence tomography. The phase and the intensity of the swept source are stable. The scanning range of the swept source is 10 nm, the full width at half maximum is 6 nm, the instantaneous linewidth is less than 0.018 nm and the average output power is 9.1 mW. Based on the Fourier-domain mode locking, the swept laser source uses a Fabry-Perot interferometer tunable filter (FFP- TF) with finesse of 5578 and narrow transmission window. Spontaneous emission of the gain medium is used as background light, and passes through the long dispersion managed delay line into the FFPTF. After filtering and parameter matching, the system can resonate and produce an ultra- stable swept laser. The factors influencing the instantaneous linewidth of the swept source are discussed. The swept laser source shows high finesse which makes it suitable for high- speed molecular spectroscopy and molecular absorption spectroscopy.