Reshaping the output of fiber lasers by using a variable intra-cavity filter based on a reconfigurable Fabry–Perot interferometer

Abstract

Abstract The shaping of the output laser by using a modifiable intra-cavity filter, which is based on a reconfigurable Fabry–Perot interferometer, is experimentally demonstrated. This output shaping method is carried out using a Fabry–Perot interferometer formed by the partially reflected faces of two single-mode fibers (SMFs). The two SMF ends are inside a capillary glass, where one is fixed, and the other one can be linearly displaced. As the free fiber is displaced, the separation distance between the planar faces is modified, which changes the interferometer properties to allow the adjustment of the laser intra-cavity losses to shape the output laser. The shaping of the output laser is focused on varying the wavelength peak number that may induce laser emissions and also shift these peaks. For the laser setup used in this work, a maximum of four simultaneous laser emissions was achieved. In addition, the experimental results for a constant interferometer separation distance provide emissions with negligible variations.