Table of Contents
Stimulated Raman scattering in multi-kilowatt fiber lasers
Definition and impact
According to scientists, stimulated Raman scattering (SRS) remains a development challenge for multi-kilowatt fiber lasers. To advance fiber laser technology toward higher-power systems while maintaining high-quality beams, manufacturers need to adopt effective SRS mitigation strategies.
Nonlinear phenomenon
Stimulated Raman scattering is a nonlinear effect. It occurs when the optical intensity exceeds a threshold value. Since a portion of the energy in the fiber laser is lost to SRS, this effect limits the achievable output power.
Optical feedback challenges
Causes and effects
Optical feedback reflected from the workpiece can lead to serious problems, such as fiber laser instabilities or damage to pump diodes. Instabilities in output power or beam quality can affect industrial processes and reduce product quality. Maintaining reliable and stable operation is essential for industrial fiber laser applications.
Transverse mode instability
Description of the effect
Even with progress in SRS management, the output power of single-mode fiber lasers rarely exceeds a few kilowatts. Transverse mode instability (TMI) is another nonlinear effect that impacts multi-kilowatt system development. TMI occurs suddenly when the average power threshold is reached, causing beam quality degradation.
Suppression and trade-offs
TMI has been studied for a long time, allowing researchers to develop effective suppression methods. However, reducing TMI can interfere with SRS suppression. Therefore, it is important to find a balance while considering reliability and technological limits.
Ongoing development and solutions
Power optimization
Fiber lasers can operate beyond the SRS threshold using current mitigation approaches. A comprehensive solution does not yet exist, so ongoing research continues to improve understanding and performance at multi-kilowatt levels. Challenges remain to achieve reliable, highly efficient industrial fiber lasers.