The authors design and demonstrate a high-reflector broadband Bragg mirror for a fiber laser system. A T-matrix formalism was used to design a broadband intracore mirror consisting of a series of Bragg gratings. Ultraviolet light from a KrF excimer laser was used in an interferometric setup to inscribe these Bragg gratings in a photosensitive fiber. This resulted in a broadband Bragg mirror covering a wavelength range of approximately 3.5 nm. An all-Bragg grating, erbium-doped fiber laser cavity is demonstrated using this Bragg mirror as the high reflector and a single narrowband Bragg grating centered at 1550 nm as the output coupler. Tunability of the fiber laser was achieved over the range of the high reflector using strain-induced changes on the output coupler.