Hannover 2013 – wissenschaftliches Programm

Bereiche | Tage | Auswahl | Suche | Aktualisierungen | Downloads | Hilfe

Q: Fachverband Quantenoptik und Photonik

Q 49: Ultrashort laser pulses: Generation II

Q 49.2: Vortrag

Donnerstag, 21. März 2013, 11:30–11:45, F 142

Beating the astigmatism in laser focusing and collimation with off-axis spherical mirrors — •Emanuel Wittmann, Niko Heinrichs, Elias Eckert, and Eberhard Riedle — LS für BioMolekulare Optik, LMU München

A central issue in ultrafast optics is the need to focus and collimate pulses with a very wide spectrum without diffractive elements. Diffractive lenses introduce an unacceptable chirp and also chromatic aberrations. Theoretically parabolic mirrors would be ideal. However, their optical quality is far inferior to spherical mirrors and the off-axis parabolics are only useful in the IR. We show that a combination of a concave and a convex spherical mirror with suitable ratio of radii of curvature can focus and collimate ultrafast pulses without any detectable astigmatism. This is found at angles where a single spherical mirror already introduces a large aberration. The new possibility is highly interesting for the collimation of NOPA seed continua generated in bulk materials and the beam management in 2D-UV spectroscopy. It renders for the first time undistorted short wavelength and duration pulses in the interaction region. In the talk the theoretical background, the implementations as well as the characterization of the spatial beam evolution are discussed. Ongoing measurements on the quality of the resulting phasefronts will conclude the presentation.