Fibre loop mirror with FBGs for the scanning range stabilisation in a fibre self-sweeping laser

A new scheme is suggested for stabilising scanning range boundaries of a self-sweeping fibre laser with fibre Bragg gratings (FBGs) and a fibre loop mirror. The mechanism for stabilising stop and/or start scanning boundaries is based on the formation of additional selective losses and/or reflection depending on the FBG position relative to the fibre mirror. It is shown that the simultaneous implementation of two selectors reduces fluctuations of the selfsweeping boundaries to several picometres, which is less by one-two orders in magnitude as compared with a case when the FBGs are absent. The approach suggested allows one to enhance predictability of emission wavelength tuning in fibre self-sweeping lasers, which is very important in practical applications.