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Controlling mode instabilities by dynamic mode excitation with an acousto-optic deflector
Hans-Jürgen Otto1, Cesar Jauregui, Fabian Stutzki
1Institute of Applied Physics, Abbe Center of Photonics, Friedrich-Schiller-Universität Jena, Albert-Einstein-Str 15, 07745 Jena, Germany. hans-juergen.otto@uni-jena.de
Optics Express
|August 14, 2013
Summary
We actively stabilize fiber amplifier beam profiles above the mode instability threshold. This significantly improves beam quality and pointing stability at high power levels.
Area of Science:
- Optics and Photonics
- Laser Physics
- Materials Science
Background:
- Mode instabilities (MI) in fiber amplifiers limit output power and beam quality.
- Existing methods struggle to maintain stable beam profiles at high power levels.
Purpose of the Study:
- To demonstrate an active stabilization technique for fiber amplifier beam profiles.
- To enhance beam quality and pointing stability beyond the MI threshold.
Main Methods:
- Implementation of an active feedback system to control the beam profile.
- Experimental validation of the stabilization approach in a fiber amplifier setup.
Main Results:
- Achieved active stabilization of the beam profile above the mode instability threshold.
- Significantly improved beam quality and pointing stability.
- Demonstrated stable operation at power levels up to three times the MI threshold.
Conclusions:
- The developed approach effectively mitigates mode instabilities in fiber amplifiers.
- Active beam profile stabilization is crucial for high-power fiber laser systems.
- The findings align with recent theoretical models explaining mode instabilities.
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