Lobach Ivan A, Kablukov Sergey I, Skvortsov Mikhail I, Podivilov Evgeniy V, Melkumov Mikhail A, Babin Sergey A, Dianov Evgeny M
Institute of Automation and Electrometry SB RAS, Novosibirsk, 630090, Russia.
Novosibirsk State University, Novosibirsk, 630090, Russia.
Sci Rep. 2016 Jul 20;6:30083. doi: 10.1038/srep30083.
Random fiber lasers operating via the Rayleigh scattering (RS) feedback attract now a great deal of attention as they generate a high-quality unidirectional laser beam with the efficiency and performance comparable and even exceeding those of fiber lasers with conventional cavities. Similar to other random lasers, both amplification and random scattering are distributed here along the laser medium being usually represented by a kilometers-long passive fiber with Raman gain. However, it is hardly possible to utilize normal gain in conventional active fibers as they are usually short and RS is negligible. Here we report on the first demonstration of the RS-based random lasing in an active fiber. This became possible due to the implementation of a new Bi-doped fiber with an increased amplification length and RS coefficient. The realized Bi-fiber random laser generates in a specific spectral region (1.42 μm) exhibiting unique features, in particular, a much narrower linewidth than that in conventional cavity of the same length, in agreement with the developed theory. Lasers of this type have a great potential for applications as Bi-doped fibers with different host compositions enable laser operation in an extremely broad range of wavelengths, 1.15-1.78 μm.
通过瑞利散射（RS）反馈工作的随机光纤激光器如今备受关注，因为它们能产生高质量的单向激光束，其效率和性能与传统腔型光纤激光器相当，甚至更优。与其他随机激光器类似，放大和随机散射在此沿激光介质分布，该介质通常由具有拉曼增益的千米长无源光纤表示。然而，在传统有源光纤中很难利用正常增益，因为它们通常较短且瑞利散射可忽略不计。在此，我们报道了在有源光纤中首次实现基于瑞利散射的随机激光振荡。这得益于一种新型双掺杂光纤的应用，其具有更长的放大长度和更高的瑞利散射系数。所实现的双掺杂光纤随机激光器在特定光谱区域（1.42μm）产生激光，展现出独特特性，特别是线宽比相同长度的传统腔型激光器窄得多，这与所发展的理论相符。由于具有不同基质成分的双掺杂光纤能使激光在1.15 - 1.78μm的极宽波长范围内工作，这类激光器具有巨大的应用潜力。
