TY  - JOUR
A1  - Vorholt, Christian
A1  - Wittrock, Ulrich
T1  - Intra-cavity pumped Yb:YAG thin-disk laser with 1.74% quantum defect
JF  - Opt. Lett.
N2  - We present, to the best of our knowledge, the first intracavity pumped Yb:YAG thin-disk laser. It operates at 1050.7 nm with a quantum defect of just 1.74% due to pumping at 1032.4 nm. Low absorption of the pump light at the pump wavelength of 1032.4 nm is compensated for by placing the disk inside the resonator of another Yb:YAG thin-disk laser which is diode-pumped at 940 nm. The intra-cavity pumped laser has an output power of 10.3 W and a slope efficiency of 8.3%
Y1  - 2015
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:hbz:836-opus-8284
VL  - 40
SP  - 4819
EP  - 4822
ER  - 
TY  - CHAP
A1  - Vorholt, Christian
A1  - Wittrock, Ulrich
T1  - Wavelength control by angle-tuning of the laser radiation in an intra-cavity pumped Yb:YAG thin-disk laser
T2  - Advanced Solid State Lasers (ASSL), paper AM5A.39
N2  - In an intra-cavity pumped thin-disk laser the pump radiation forms a standing wave pattern inside the intra-cavity pumped disk.We demonstrate experimentally that the grating period of the standing wave pattern of the pump radiation can control the laser wavelength.
Y1  - 2015
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:hbz:836-opus-8298
UR  - https://www.osapublishing.org/abstract.cfm?uri=ASSL-2015-AM5A.39
ER  - 
TY  - JOUR
A1  - Rausch, Peter
A1  - Verpoort, Sven
A1  - Wittrock, Ulrich
T1  - Unimorph deformable mirror for space telescopes: design and manufacturing
JF  - Opt. Expr.
N2  - Large space telescopes made of deployable and lightweight structures suffer from aberrations caused by thermal deformations, gravitational release, and alignment errors which occur during the deployment procedure. An active optics system would allow on-site correction of wave-front errors, and ease the requirements on thermal and mechanical stability of the optical train. In the course of a project funded by the European Space Agency we have developed and manufactured a unimorph deformable mirror based on piezoelectric actuation. The mirror is able to work in space environment and is designed to correct for large aberrations of low order with high surface fidelity. This paper discusses design, manufacturing and performance results of the deformable mirror.
KW  - Active or adaptive optics
KW  - Telescopes
KW  - Space optics
KW  - Space instrumentation
Y1  - 2015
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:hbz:836-opus-8227
VL  - 23
SP  - 19469
EP  - 19477
ER  - 
TY  - JOUR
A1  - Wittrock, Ulrich
A1  - Vorholt, Christian
T1  - Spatial hole burning in Yb:YAG thin-disk lasers
JF  - Appl. Phys. B
N2  - The spatially varying intensity in a standing wave resonator leads to spatial hole burning in the gain medium of a laser. The spatial hole burning changes the gain of different longitudinal modes and can thus determine the optical spectrum of the laser. We simulate this longitudinal mode competition in standing wave resonators of thin-disk lasers. The resulting optical spectra of the laser are compared to measured optical spectra. We examine two types of resonators: I-resonators and V-resonators with different angles of incidence. In V-resonators, the non-normal incidence of the laser beam on the disk lifts the degeneracy of the polarization. Experiments show that the slight gain advantage for the p-polarization does not lead to polarized emission. For both types of resonators, the measured spectra are in good agreement with the simulated ones. The simulations allow to study the influence of spectral intra-cavity losses on the optical spectrum of a thin-disk laser.
Y1  - 2015
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:hbz:836-opus-8234
VL  - 120
SP  - 711
EP  - 721
ER  -