CW 7-W, 900-nm-wide supercontinuum source by phosphosilicate fiber Raman laser and high-nonlinear fiber

摘要

High-power, continuous-wave (CW) supercontinuum spanning from 1200 to 2100 nm has been generated in an all-fiberconfiguration. The output of a CW 8-W phosphosilicate fiber Raman laser at 1556 nm was efficiently converted to thesupercontinuum in the successive high-nonlinear dispersion-shift fiber with the zero-dispersion wavelength of 1539 nm.The fiber-length and input-power dependences were investigated, and both the spectral broadening and continuum powerare found to be strongly affected by the 2220-nm absorption band in silica. An average power of 6.8 W and a 20-dBbandwidth of 900 nm were obtained from the optimal 150-m fiber length. Very flat spectral intensity of 10±1 mW/nmfrom 1640 to 2015 nm is also a noteworthy feature. Raman-assisted four-wave mixing driven by modulation instabilityis the most possible mechanism of the presented CW supercontinuum generation and well explains the spectral cutoffs.