Abstract
We design a double-clad fiber with a W-type core for use in a
cladding-pumped fiber Raman amplifier operating at the 1st-Stokes
wavelength. Compared to a conventional step-index core, a W-type core allows
for a larger inner cladding so that pump sources with relatively poor beam
quality can be utilized. This is because parasitic Raman conversion to the
2nd Stokes can be suppressed by bending loss, while the sharp spectral
characteristics of a W-type fiber allows the loss to be kept low at the 1st
Stokes. Without bendloss filtering, the ratio between the inner-cladding
area and the effective area of the Stokes wave is limited to approximately
eight. With a bendloss-filtered W-type fiber, area ratios of 34 are possible
for core diameters up to around 18 $\mu$m and inner-cladding diameters up to around 82 $\mu$m. We also discuss limitations on the brightness enhancement due
to optical damage and pump—signal walk-off in the pulsed
regime.
© 2010 IEEE
PDF Article
More Like This
Cited By
You do not have subscription access to this journal. Cited by links are available to subscribers only. You may subscribe either as an Optica member, or as an authorized user of your institution.
Contact your librarian or system administrator
or
Login to access Optica Member Subscription