Revolutionizing laser material processing with the coherent beam combination

Exail has been the supplier of phase modulators to the company Civan Lasers for a decade. Such a high-performance optical component is key to efficiently combining multiple laser beams into one unique very-powerful laser, thanks to the Coherent Beam Combination (CBC) technique.

The most advanced laser solution based on the Coherent Beam Combining (CBC) technique

Civan Lasers was founded in 2008, and for a decade the company developed the building blocks of their unique beam combining technology. After several demonstration models, the first prototype of Dynamic Beam Laser was presented in 2018. The technology, which was secured with more than 90 patents along the way, became the unique commercial laser based on the Coherent Beam Combination (CBC) technique. The technology takes advantage of the control of the phase of different individual laser channels combined into a more powerful one. “Our industrial lasers can reach up to 100kW. They combine up to 400 lasers, and we are already planning much more powerful setups.” highlight Ami Spira, VP Marketing at Civan Lasers.

With a focus on material processing applications, typically for welding and cutting, the CBC technology developed by Civan Lasers is also adapted for metal additive manufacturing, surface treatment, and free-space-optical communication. The CBC technique offers extreme control of the laser beam shape, which is a real advantage for the most complex welding tasks (deep penetration up to 70 mm) and the most complex types of metals (i.e aluminum used in automotive applications). Light propulsion and space debris removal are other potential applications that could arise in the future.

Among the different methods that can be used to implement the CBC technique, Civan Lasers technology specifically addresses the Optical Phase Array (OPA – or tiled aperture CBC) method which allows to generate a dynamic beam, and the Filled aperture – CBC method that generates a static beam. With both techniques it is possible to generate high-beam quality and high-power. A dynamic beam will allow to steer the beam, which is useful for welding and material processing. It is also useful for free-space optical communication thanks to the capability to adapt the beam wave front according to the atmosphere and to stabilize line of sight by electro-optical steering of the beam. A static beam allows to combine many beams together into a powerful single mode laser beam. With this latest method, the company recently developed a 500-W single-mode continuous-wave green laser (emitting at 532 nm), marking a world record for such a laser type.

Leveraging Exail industry know-how in LiNbO₃ electro-optic modulation

Gaining power with multiple combined laser beams by using the Coherent Beam Combination (CBC) technique means having real-time control of their relative phases. Exail has developed dedicated low frequency phase modulators for this application. Civan Lasers uses such modulators on each of the many channels combined into its CBC laser systems, and the company has developed the electronics package and the algorithm to control the phase modulators.

Exail has unique know-how in the development of electro-optical phase modulators, and the company was chosen by Civan Lasers as a supplier after testing the few other vendors of this technology worldwide. The collaboration started during the development process of Civan Lasers CBC technology. Exail components were implemented in the first prototype, as early as 2015. Unlike most of the phase modulators delivered by Exail, the collaboration with Civan Lasers is for custom made components. It has allowed the company to integrate the components into their own phase modulation solution, leveraging the high-performance and high reliability at the core of Exail technology.

On top of the stability and reliability of Exail components, the main advantage for Civan Lasers has been the overall performance repeatability reached by the different components delivered. Exail delivered cost-effective solutions allowing the mass production of CBC laser systems.

Civan Lasers is involved in several research collaborations, such as the one with Fraunhofer IWS, Siemens, and Thyssenkrupp that led to the development of the 500 W green laser, which helps the company to evaluate the capabilities of their unique technology.

Thanks to the CBC technique, Civan Lasers can upgrade its technology and change the overall architecture of its laser systems without increasing much of the power injected in each channel. It means that their laser systems do not face any major power handling issue while increasing the whole power. The company will keep relying on Exail high value/cost efficient modulation solutions for the next generation of industrial laser they are conceiving today.