All fiber adjustable beam shaping

An optical beam delivery system for generating adjustable composite beam shapes in response to controllable perturbation, comprising:

• multiple input fibers, each of which is configured to receive at its input a different laser beam and to provide at its output a corresponding intermediate beam;
• a fused fiber combiner configured to couple outputs from the multiple input fibers into a divergence-preserving fiber that preserves a combined divergence distribution of the intermediate beams;
• an output lens configured to convert the combined divergence distribution to an output transverse spatial intensity distribution defining a composite beam shape of an output beam, the output transverse spatial intensity distribution including a superposition of individual output beams corresponding to the multiple input fibers;
• and
• at least one of the multiple input fibers having a tunable fiber assembly, the tunable fiber assembly having a series of first, second, and third portions, the first portion configured to adjust an input transverse spatial intensity distribution in response to the controllable perturbation, the second portion configured to convert the input transverse spatial intensity distribution to an intermediate divergence distribution, and the third portion configured to preserve the intermediate divergence distribution that is delivered to the fused fiber combiner.