In coherent beam combining (CBC) technology, multiple laser beams are combined to produce one high power single mode (SM) beam. The main challenges in CBC of high power laser beams are precision beams alignment, thermal effects and non linear effects. Recently, after overcoming several problems in these fields, two CBC systems with very high power were constructed.

The first system is a 5kW, SM laser. In this system 11 laser beams were coherently combined on a diffractive element (filled aperture combination scheme) with > 95% CBC efficiency and M2 <1.1.

The second system is a 14kW laser with dynamic beam. In this system 32 beams, were coherently combined in the far field (tiled aperture scheme). In this combining method, also known as optical phased array (OPA) CBC, the beams of the multiple channels are directed to overlap and combine in the far field and create a diffraction pattern. The position and shape of the diffraction pattern is controlled by the relative phases of the individual channels. By manipulating the relative phase beam steering, beam focusing and beam shaping were demonstrated at 20 MHz speed. This high power laser with dynamic beam, can provide significant advantages in material processing.

In these two combining methods, the number of combined beams can be increased in order to increase the output power up to tens of kW, without any additional physical limit. Larger number of beams will also increase the scanning range and improve the resolution of the beam shapes in the case of the dynamic beam.