Raphaël Florentin

TL;DR: In this paper, an adaptive shaping of the input wavefront, only based on the output intensity pattern, has led to an amplified pulse focused both in space (1/32) and in time (1 /10) despite a strong modal group delay dispersion.

TL;DR: In this article, an adaptive shaping of the input wavefront, only based on the output intensity pattern, has led to an amplified pulse focused both in space (1/32) and in time (1 /10) despite a strong modal group delay dispersion.

TL;DR: In this article , a low-cost blue laser diode was used as the pump source and a sealed dye cell with no flowing circuitry, resulting in a device that combines the convenience and size of a solid-state device with the stability of a liquid organic laser.

Abstract: Controlling the output beam of a multimode fiber (MMF) is quite a hot topic currently because it offers several attractive perspectives. Among the various technics used to shape the output beam of a multimode fiber, the adaptive approaches rely on a measurement (objective function) which feeds an algorithm for further command of a spatial modulator for optimization. This approach gives several advantages: it does not need knowledge of the transmission matrix of the fiber, it is resilient to fiber perturbations and energy conservation is not needed. Beam focusing and profiling have been achieved already through a standard MMF [1], and more recently in an amplifying Yb-doped MMF [2] but using CW laser light. For some applications regarding amplification or nonlinear imaging one needs at the same time a control on both the spatial shape and the temporal shape.