Enhancement of Brillouin signal in plastic optical fibers using pulsed pump with multi mode-fiber-assisted coupling

摘要

A cost-effective technique for coupling a plastic optical fiber (POF) to a silica single-mode fiber (SMF) is proposed, which can, by exploiting a multimode fiber (MMF), avoid the damage or burning at the butt-coupled POF/SMF interface. Using this coupling technique, we also show that the Brillouin Stokes power 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, duty ratio of 15%, and pulse period of 2 μs is launched into a 200-m-Iong 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 non-monotonic, which might originate from a longer phonon lifetime in POFs than that in silica SMFs.