Scattering and reflection of transmission band power in a fiber amplifier cause increased bit-error rates through multiple path interference (MPI). We report a passive method for reducing MPI contributions from the front facet of a 980-nm fiber-Bragg-grating-stabilized pump laser by use of a Tm<sup>3+</sup> -doped fiber pigtail between the diode facet and the fiber Bragg grating. Optical return loss in the C band is reduced to below -30dB .
© 2004 Optical Society of America
(060.2280) Fiber optics and optical communications : Fiber design and fabrication
(140.5960) Lasers and laser optics : Semiconductor lasers
(160.2290) Materials : Fiber materials
(160.5690) Materials : Rare-earth-doped materials
Monica K. Davis, Matthew J. Dejneka, and Jim Ainslie, "Tm3+ cladding-doped fiber for selective wavelength filtering in high-power pump lasers," Opt. Lett. 29, 712-714 (2004)