Precision and Intelligence Laboratory, Tokyo Institute of Technology, Midori-ku, Yokohama, Japan.
Opt Lett. 2013 May 1;38(9):1467-9. doi: 10.1364/OL.38.001467.
A cost-effective technique for coupling a polymer optical fiber (POF) with 50 μm core diameter to a silica single-mode fiber (SMF) with 8 μm core diameter is proposed, which can, by exploiting a multimode fiber with 50 μm core diameter, avoid the damage or burning at the butt-coupled POF/SMF interface. Using this coupling technique, we also show that the Brillouin signal in a POF can be enhanced by combined use of pulsed pump and an erbium-doped fiber amplifier. When the pulsed pump with average optical power of 18 dBm (63 mW), duty ratio of 15%, and pulse period of 2 μs is launched into a 200 m-long POF, 4 dB enhancement of the Stokes power is obtained compared to that with 18 dBm continuous wave pump. The relatively small enhancement is probably caused by the high Brillouin threshold of POFs. The Stokes power dependence on duty ratio is nonmonotonic, which might originate from a longer phonon lifetime in POFs than that in silica SMFs.
提出了一种将 50μm 芯径聚合物光纤（POF）与 8μm 芯径二氧化硅单模光纤（SMF）耦合的经济高效技术，该技术利用 50μm 芯径多模光纤可以避免在对接耦合的 POF/SMF 界面处发生损坏或燃烧。使用这种耦合技术，我们还表明，通过同时使用脉冲泵和掺铒光纤放大器，可以增强 POF 中的布里渊信号。当将平均光功率为 18dBm（63mW）、占空比为 15%、脉冲周期为 2μs 的脉冲泵注入 200m 长的 POF 中时，与 18dBm 连续波泵相比，斯托克斯功率得到了 4dB 的增强。相对较小的增强可能是由于 POF 的布里渊阈值较高所致。斯托克斯功率与占空比的关系是非单调的，这可能源于 POF 中的声子寿命比二氧化硅 SMF 中的声子寿命长。
