Optimized active multicore fiber bending sensor

We present a study of the feasibility of transforming the multicore fiber in a supermode-interference based bending sensor into an active stage. By compensating the antisymmetric supermode losses for high curvatures, fringe visibility is improved and the sensor operating range can be extended. For a given multicore fibre length and Er3+-ion concentration sensor calibration curves allow assessing the bending radius by measuring the visibility as a function of the input pump power. The Er3+-ion concentration, available input pump power and multicore fiber length set the minimum bending radius that could be measured.