Large effective mode area fibers for high power lasers and amplifiers

摘要

Fiber laser offers better stability, better mode quality, an ease of manufacturing, compactness and potentially lower cost, comparing to their solid state counterparts. The highly confined optical mode in an optical fiber, however, also leads to very high intensity in the fiber, which limits operation of high peak power in fiber lasers due to a range of nonlinear effects such as serf-phase modulation, Raman scattering and Brillouion scattering. One of the most challenging areas of application is femtosecond fiber lasers with pulse energy exceeding tens of μJ. various approaches have been studied to combat nonlinear effects, the most effective approach being an increase of EMA in an optical fiber. As nonlinearity scales inverse proportional to EMA, an order of magnitude of higher nonlinearity can be obtained using one of the commercially available large effective mode area fibers.