Huang Long, Ma Pengfei, Tao Rumao, Shi Chen, Wang Xiaolin, Zhou Pu
Appl Opt. 2015 Apr 1;54(10):2880-4. doi: 10.1364/AO.54.002880.
A linearly polarized monolithic fiber laser based on a master oscillator power amplifier structure with a master oscillator and a one-stage power amplifier is reported. We design a homemade oscillator based on the theory that, in the coiled gain fiber, the higher modes and the polarized mode of the fundamental mode along the fast axis are suppressed effectively because of their obviously higher bend loss than that of the polarized mode of the fundamental mode along the slow axis. The oscillator operates at 1080 nm, launching a 30 W seed laser with a high polarization extinction ratio of 19 dB into the power amplifier via a mode field adapter. The power amplifier utilizes Yb-doped polarization-maintaining fiber of 20/400 μm, which produces nearly diffraction-limited output power of about 1.5 kW with an optical-optical efficiency of 81.5% and a polarization extinction ratio of 13.8 dB. Both the M(x)² factor and the M(y)² factor of the collimated beam are measured to be about 1.2. The spectral width of the output power is broadened approximately linearly, and the full width at half maximum of the spectrum at the maximum output power is about 5.8 nm. It is known as the highest linearly polarized output power to the best of our knowledge.
报道了一种基于主振荡功率放大器结构的线性偏振单块光纤激光器，该结构包括一个主振荡器和一个单级功率放大器。我们基于这样的理论设计了一个自制振荡器：在盘绕增益光纤中，高阶模和沿快轴的基模偏振模由于其弯曲损耗明显高于沿慢轴的基模偏振模，从而被有效抑制。该振荡器工作在1080nm，通过模场适配器将一个高偏振消光比为19dB的30W种子激光注入功率放大器。功率放大器采用20/400μm的掺镱保偏光纤，产生近衍射极限输出功率约1.5kW，光光效率为81.5%，偏振消光比为13.8dB。准直光束的M(x)²因子和M(y)²因子测量值均约为1.2。输出功率的光谱宽度近似线性展宽，最大输出功率时光谱的半高全宽约为5.8nm。据我们所知，这是最高的线性偏振输出功率。
