Bismuth-doped and bismuth/erbium co-doped optical fibres have attracted much attention for their great potential in the photonic applications at ultrawide O, E, S, C and L bands. The effects of post treatments, including various heating, high energy ray radiation, laser radiation and H 2 loading processes, on these fibres' performance, functionality and stability have been experimentally studied. Experimental results demonstrate that these post treatments could allow us to get insights regarding the formation and the structure of bismuth active centre (BAC) and be used to control and regulate the formation of BAC.Keywords: bismuth-doped fibre (BDF), bismuth and erbium co-doped optical fibre (BEDF), bismuth active centre (BAC), broadband, post treatments, thermal treatment, gamma radiation, photo-bleaching, H 2 loading