Dresden 2011 – scientific programme

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Q: Fachverband Quantenoptik und Photonik

Q 13: Laserentwicklung: Festkörperlaser 1

Q 13.3: Talk

Monday, March 14, 2011, 15:00–15:15, SCH A215

Thermo-Optical Aberrations of the Gain Medium of an Yb:YAG Thin-Disk Laser — •Julian Perchermeier, Sven Verpoort, and Ulrich Wittrock — Muenster University of Applied Sciences, Photonics Laboratory, Stegerwaldstr. 39, 48565 Steinfurt, Germany

We present interferometric measurements of the thermo-optical aberrations of an Ytterbium doped YAG thin-disk laser. The thin-disk laser concept itself was invented to minimize thermal aberrations induced by the active laser medium. The top-hat pump spot, which has a homogeneous intensity distribution, causes a strong temperature gradient in radial direction at the border to the unpumped region of the disk. This temperature distribution leads to diffraction losses which are detrimental for an efficient laser operation, especially with fundamental mode laser operation. Since the light circulates about 20 times inside the resonator, the resonator is very sensitive to thermo-optical aberrations. To measure these small aberrations, we use a phase-shifting Twyman-Green interferometer with a high resolution. We measured the thermo-optical aberrations of the thin-disk for different pump powers with and without lasing operation. The results will allow us to manufacture a custom-made deformable mirror to compensate for the measured thermo-optical aberrations of the thin-disk in a future step.