High-power Random Raman Fiber Laser with an Ultrashort Random Fiber Grating

We propose and demonstrate the power scalability in a novel random Raman fiber laser (RRFL) with localized random feedback provided by an ultrashort low-reflection random fiber grating (RFG). The RFG is composed of a randomly distributed sub-grating array, and is directly written by a femtosecond laser with point-by-point inscription approach. The fabricated RFG has a total length of only 1.86 mm ...