Characterization of transverse mode instability with a 4-quadrant photodiode

Area of Science:

• Optics and Photonics
• Laser Physics
• Materials Science

Background:

• Transverse mode instability (TMI) limits power scaling in fiber lasers.
• Reliable TMI monitoring is crucial for laser system development.
• Distinguishing TMI from other perturbations is challenging.

Purpose of the Study:

• Develop a novel, cost-effective method to monitor and characterize TMI.
• Enable TMI dynamics characterization despite power fluctuations.
• Provide insights into TMI phenomena.

Main Methods:

• Utilized a position-sensitive detector to track beam movement.
• Recorded beam position data along X and Y axes.
• Analyzed the temporal evolution of the beam's center of gravity.

Main Results:

• Successfully characterized TMI dynamics using beam trajectories.
• Demonstrated robustness against power fluctuations.
• Obtained rich information about TMI from beam movement patterns.

Conclusions:

• The developed method offers a reliable way to monitor TMI.
• This technique aids in distinguishing TMI from other dynamic perturbations.
• The approach provides deeper understanding of TMI in fiber lasers.