Suppressing nonlinear effects such as stimulated Brillouin scattering (SBS), stimulated Raman scattering (SRS) in high power fiber amplifiers and lasers is crucial for scaling up output power well beyond kW levels. The paper uses a sophisticated model to analyze many different fiber amplifier designs and compare their performance. The systematic modeling reveals many interesting results and shows that a co-pumped amplifier can be optimized by carefully choosing fiber lengths and applying additional heating to the fiber. It also explains why the amplifier configuration can make great impacts on SBS characteristics. In addition, a single-polarized fiber having an effective area of 206 μm² and cutoff wavelength of 1100 nm is designed to suppress SRS and provide better polarization properties. The systematic modeling concludes that in general a counter-pumped fiber amplifier has the lowest nonlinear effects and is less sensitive to the fiber length comparing with the co-pumped amplifiers. However, the co-pumped amplifier is easy to integrate with an all-fiber-based pump combiner without risking LD damage and it can be heated to increase SBS threshold by a factor of 1.7.

Date Published: 21 November 2007
PDF: 12 pages
Proc. SPIE 6781, Passive Components and Fiber-based Devices IV, 67810H (21 November 2007); doi: 10.1117/12.745958

Published in SPIE Proceedings Vol. 6781:
Passive Components and Fiber-based Devices IV
Ming-Jun Li; Jianping Chen; Satoki Kawanishi; Ian H. White, Editor(s)