本文提出了一种可以实现光纤高阶模式(HOM)在激光腔内振荡的锁模掺镱光纤激光器。通过使用一对级联的模式选择耦合器(MSC)作为有效的模式转换器，获得光纤锁模激光腔内HOM产生。其中，制备的MSC中心波长为1064 nm，可实现80 nm的模式转换带宽和94%的高阶模式纯度。通过搭建掺镱锁模光纤激光器，实验获得了3 dB谱宽7.4 nm、脉冲重复频率10.9 MHz、射频信噪比55 dB的锁模脉冲激光，输出功率的斜率效率为2.3%。实验证明，这种方法可在激光器内部通过模式级联转换，且能参与腔内锁模过程获得脉冲HOM激光。

We demonstrate a mode-locked Yb-doped fiber laser (YDFL) that enables fiber high-order mode (HOM) oscillation inside the ring cavity, by using a pair of mode selective couplers (MSCs) as an effective mode converter, the optical fiber HOM is obtained. The central wavelength of MSC is located at 1064 nm, which can achieve 80 nm mode conversion bandwidth and 94% high-order mode purity. A mode-locked pulsed fiber laser with a 3 dB spectral width of 7.4 nm, a pulse repetition frequency of 10.9 MHz, and a radio frequency signal-to-noise ratio of 55 dB is obtained, and the slope efficiency of the output power is 2.3%. These results show that the HOM can be directly oscillated by the cascaded MSCs in the fiber laser and participated in the mode-locking process to obtain a pulsed HOM laser.