Broadband Supercontinuum Generation Based on Ytterbium-Doped Fiber Amplifier Seeded by Self-Pulsed Amplified Spontaneous Emission Source

We report a novel method to obtain high-power near-infrared broadband supercontinuum based on amplified spontaneous emission (ASE) source. Firstly two kinds of ASE seed sources, without and with parasitic laser, are amplified to be 19.1 and 19.9 W, respectively, using a fiber amplifier. Then, comparative experiments are performed by using these two sources to pump different fibers. When using the ASE source without parasitic laser to pump a piece of 1000-m single-mode fiber, six orders Stokes waves are generated to extend the spectrum to beyond 1500 nm. But the spectrum is not flat with clear discrete Stokes peaks. When a section of 150-m double-clad passive fiber is pumped by the ASE source with parasitic laser, 18.3 W supercontinuum with 20 dB spectral range covering from 1030 to 1650 nm is generated. And the continuous ASE source becomes a stochastic pulsed light owing to parasitic lasing and self-pulse effect without any artificial modulation. This method combines the merits of ASE source and pulsed light, which are simplicity and low cost of the former and high peak power of the latter.