2. Inconsistent combination techniques

The fundamental principle of laser combination is based on the addition of the powers emitted by several single laser sources. The first approach to consider is therefore laser beam stacking, where several laser beams are aligned so that they illuminate the same area of a target or object, or of the environment to be measured. The total added power of the lasers is then theoretically equal to the sum of the powers emitted by each laser.

However, this reasoning is only true if the laser beams do not interfere in the plane where they overlap. Many laser beams are highly coherent, i.e. all photons emitted by a single laser source share the same wavelength, polarization and phase. If all laser sources are identical, they also share the same wavelength and polarization. As a result, they will interfere by superimposing each other, generating an interference pattern made...