ABSTRACT
In this article, we present robust passively mode-locked femtosecond lasers operating at 1030 and approximately 2000â nm, respectively. The all-fiber, all-polarization-maintaining (PM) lasers are mode-locked by a nonlinear amplifying loop mirror (NALM) which is attached to the cavity by a 3×3-coupler. The NALM is phase-biased by the coupler, enabling turn-key operation of the oscillator. Femtosecond pulse generation is demonstrated using Ytterbium and Thulium doped active fibers. Depending on the wavelength and the installed dispersive elements, pulse formation can be aided by a range of attractors including self-similar pulse evolution, soliton, or dispersion-managed soliton formation.
ABSTRACT
A novel concept for dynamic focus shaping based on highly efficient coherent beam combining with micro-lens arrays (MLAs) as the combining element is presented. This concept allows us to control the power weights of diffraction orders by varying the absolute phases of an array of input beams. A proof-of-principle experiment is supported by simulations. For this, an input beam matrix of 5×5 beams is combined proving both the ability for further power scaling and dynamic focus shaping.
ABSTRACT
A novel, to the best of our knowledge, concept for coherent beam combining is presented based on a simple setup with micro-lens arrays. These standard components are used in a proof-of-principle experiment for both coherent beam splitting and a combination of 5×5 beams. Here a combination efficiency above 90% is achieved. We call this novel concept "mixed aperture."
