# Exploring five types of beam shaping using tiled-aperture coherent beam combining

## TL;DR

This paper shows how combining laser beams coherently can shape and steer light beams in 3D space, enabling versatile optical systems.

## Contribution

The study introduces a method to use coherent beam combining to approximate and control optical elements' phase profiles for beam shaping and steering.

## Key findings

- Coherent beam combining can approximate phase profiles of optical elements like spherical lenses and axicons.
- The combined beam focus can be steered and rotated in 3D space using phase-only control.
- Experimental validation confirms the feasibility of shaping and steering beams without moving parts.

## Abstract

Coherent Beam Combination (CBC) presents a promising solution to circumvent the power-scaling limitations of High-Power Fiber Lasers (HPFLs) by spatially combining the outputs of multiple independently pumped fibres. This parallel pumping configuration allows each fibre to operate below the critical threshold that would otherwise lead to instability, whilst their combined output exceeds the maximum power achievable from a stably operating HPFL. In this work, we demonstrate that manipulating the relative phases between fibre outputs extends the capabilities of CBC to approximate the phase profiles of optical elements such as spherical lenses, axicon lenses, and spiral phase plates, enabling versatile beam focus shaping and steering. We further show that the combined beam focus, whether coherently combined or shaped into a bespoke profile (e.g. Bessel-like, orbital angular momentum), can be steered and rotated in three-dimensional space through phase-only control. These results are experimentally validated through spatial light modulation to simulate collimated fibre outputs with controllable relative phases. Our findings advance CBC systems beyond mere power scaling, offering pathways for highly versatile beam shaping and steering, with implications for next-generation multifunctional optical power delivery systems.

Yunhui Xie and colleagues report a method that treats a coherent beam combining system as a phased array. They show it can approximate phase-delaying optics to steer, shape and rotate the focus without moving optics, increasing system flexibility.