We propose and experimentally demonstrate a novel switchable triple-wavelength erbium-doped fiber laser using linear cavity structure. It is composed of two Sagnac loops that act as cavity mirrors in the resonant cavity. The left loop consists of a 3 dB fiber coupler (FC), a three-ring polarization controller (PC), and a phase-shifted fiber grating. The right loop consists of a same 3 dB FC, a same PC and a length of multimode fiber with 50 m core diameter. The two loops based on different operation principles become two comb filters to jointly excite the multiwavelength output. On the role of the polarization hole burning effect, after adjusting the two PCs, the laser can switch flexibly to output three kinds of different modes from single-wavelength to the triple-wavelength. All lasing lines with a narrow linewidth less than 0.4 nm have the optical signal-to-noise ratio of more than 28 dB.

我们提出并实验证明了一种使用线性腔结构的新型可切换三波长掺铒光纤激光器。它由两个萨格纳克环路组成，在谐振腔中充当腔镜。左环路由 3 dB 光纤耦合器 (FC)、三环偏振控制器 (PC) 和移相光纤光栅组成。右环路由相同的 3 dB FC、相同的 PC 和一段长度为 50米芯径。基于不同工作原理的两个回路成为两个梳状滤波器，共同激发多波长输出。在偏振烧孔效应的作用上，调整两台PC后，激光器可以灵活切换，输出从单波长到三波长三种不同的模式。所有窄线宽小于 0.4 nm 的激光线都具有超过 28 dB 的光信噪比。