TY  - CHAP
A1  - Wittrock, Ulrich
A1  - Welp, Petra
T1  - Adaptive laser resonator control with deformable MOEMS mirrors
T2  - MEMS/MOEMS Components and Their Applications III, Proc. SPIE
N2  - Adaptive laser resonators with deformable MOEMS mirrors under closed-loop control are discussed and experimental results are presented. The requirements for deformable mirrors and for closed-loop control systems of these mirrors are analyzed. Several deformable mirrors have been characterized and the results are presented. Currently available membrane mirrors deform under laser load and need further development before they can be used for aberration correction of solid state lasers above some tens of Watts. Nevertheless, the results are encouraging and the requirements are within reach of currently available technology. Finally, we demonstrate an Nd.YVO4-laser with a closed-loop adaptive resonator and more than 6 W of output power. The closed-loop system was able to compensate artificially introduced aberrations from a phase plate.
Y1  - 2006
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:hbz:836-opus-6537
VL  - 6113
SP  - 61130C
PB  - SPIE
ER  - 
TY  - JOUR
A1  - Heuck, Hans-Martin
A1  - Neumayer, Paul
A1  - Kühl, Thomas
A1  - Wittrock, Ulrich
T1  - Chromatic aberration in petawatt-class lasers
JF  - Appl. Phys. B
N2  - In order to avoid optical damage and non-linear effects, high-power, high-energy lasers of the petawatt class like PHELIX (petawatt high-energy laser for heavy-ion experiments) use large-aperture optics. Usually, chromatic aberration associated with these optical elements is neglected. By means of numerical simulations, we show how the chromatic aberration affects the focal intensity pattern. In particular, we make quantitative predictions of how chromatic aberration decreases the focused peak intensity. Furthermore, we prove the feasibility of a new interferometer that measures the temporal pulse front distortions which arise from expansion telescopes. We also propose a scheme that pre-compensates these distortions.
Y1  - 2006
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:hbz:836-opus-6523
VL  - 84
SP  - 421
EP  - 428
PB  - Springer
ER  - 
TY  - JOUR
A1  - Buske, Ivo
A1  - Wittrock, Ulrich
T1  - Diffraction analysis of aberrated laser resonators
JF  - Appl. Phys. B
N2  - A numerical analysis of laser resonators with aberrations is presented. {T}he analysis shows that aberrations lead to large diffraction losses of laser resonators which are laid out to produce diffraction-limited beam quality. {S}tatic or dynamic compensation of the aberrations is possible and would yield much higher output power.
Y1  - 2006
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:hbz:836-opus-8252
VL  - 83
SP  - 229
EP  - 233
ER  -