Conclusion

Techniques such as incoherent combination, polarization combination, spatial superposition and spectral combination are relatively simple to implement, and enable the powers of several lasers to be added very effectively. However, these techniques do not generally give access to the combination of more than a few dozen laser sources, at least without sacrificing their simplicity, reliability and robustness.

Coherent combination techniques, whether passive or active, are more complex in appearance, since they use an interference pattern between the combined laser beams to concentrate the power.

Passive coherent combination techniques are also very limited in terms of the maximum number of laser sources that can be combined, and it seems difficult to add up the power of more than a few dozen lasers in this way.

On...