The Fibre Bragg Grating(FBG) for 980nm pump laser is a fibre Bragg grating made by ultraviolet laser pulse on a single mode fibre. The product is connected to the 980nm pumped laser as the tail fibre, and an external cavity feedback is formed outside the pumped laser to lock the output spectral wavelength near the central wavelength of the fibre grating.

At the same time, the fibre Bragg grating has a very low temperature sensitivity coefficient, so it greatly improves the stability of the output wavelength of the 980nm pumped laser, and reduces the requirement of the pumped laser for temperature control. Because the output spectrum of the pumped laser is narrowed, the proportion of the output optical power in the EDFA erbium ion absorption band is increased and stable, which improves the pumping efficiency and stability of the EDFA.