Efficient 980 nm ytterbium-doped monolithic fiber laser using chirped and tilted fiber Bragg grating

In this paper, a single chirped and tilted fiber Bragg grating (CTFBG) was inserted in the cavity of a 20/80 μm ytterbium-doped fiber laser (YDFL) to suppress the detrimental amplified spontaneous emission (ASE) at 1030 nm. Under 30 W pump power, the output power and slope efficiency of the 20/80 μm YDFL with single CTFBG were achieved at 6.4 W and 27%. Compared to the 20/80 μm YDFL without CTFBG, the 20/80 μm YDFL employing single CTFBG increased the parasitic oscillation active fiber length from 0.82 m to 1.35 m.