Fiber lasers and amplifiers are the ideal source for high-power laser applications, particularly under challenging environmental conditions. Based on either ytterbium (Yb) or erbium (Er) fibers, these systems are able to deliver a high average power level with good wall-plug efficiency, while maintaining a compact footprint and providing robust and reliable operation, even under harsh environmental conditions. With recent developments in power scaling and high-power fiber components, the performance of Yb-based systems has been pushed beyond 1 kW, while still maintaining excellent beam quality. This parameter is of crucial importance in many applications that rely on the excellent focusability of the beam or require a directed high-power laser beam over long distances with a minimal divergence angle, e.g., defense applications or deep space optical communication (DSOC).

These applications in particular require even higher average laser powers in the range of 10 to 40 kW. However, currently the output power of a fiber laser system is limited to ~ 2–3 kW by several challenging factors, such as mode instabilities, thermal problems, and nonlinear effects (SBS or self-focusing). Further scaling can be done by increasing the fiber core size, which comes at the expense of beam quality.

Laser beam combining is therefore the most promising and commonly used approach for achieving power levels beyond 5 kW with excellent beam quality. Several methods have been successfully used, namely coherent beam combining (CBC), incoherent beam combining and spectral beam combining (SBC).

All these methods rely on high-power capable fiber components that are able to handle kW power levels and are robust with respect to challenging environmental conditions. The system’s performance and reliability will crucially depend on the components quality and robustness. This especially refers to the fiber interface solutions, beam delivery fibers and most important the beam combiner head, which is required to preserve the high precision and manufacturing quality even at high powers in the kW-level and changing environmental conditions. In order to achieve a high combining efficiency (power in bucket, PIB) and good beam quality M2, the relative position and angle precision of each channel needs to be maintained even under extreme operating conditions.

With almost one decade of experience in beam combining, FiberBridge Photonics offers unrivaled quality and precision of both individual components and full beam combining systems that can be customized to your specific application.