Suppression of Raman gain in single-transverse-mode dual-hole-assisted fiber

Measurements of backscattered Raman amplified spontaneous emission in single-mode dual-hole-assisted fiber indicate suppression of Raman gain by more than two orders of magnitude compared to SMF. These results imply that fiber lasers based on the dual-hole-assisted fiber design are effectively immune to SRS, thus enabling significant power scaling beyond current limits from a single-mode core.