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

MO: Fachverband Molekülphysik

MO 16: Posters 3: Experimental Techniques and Theoretical Approaches

MO 16.3: Poster

Donnerstag, 9. März 2017, 17:00–19:00, P OG1

The Stability of Broadband Phase Shaping in Liquid Crystal Spatial Light Modulators — •Elisabeth Brühl, Tiago Buckup, and Marcus Motzkus — Physikalisch-Chemisches Institut, Ruprecht-Karls Universität Heidelberg, Germany

Liquid crystal spatial light modulators (LCM) have found many successful applications in physical chemistry, where they are used to modulate phase, amplitude and polarization of femtosecond (fs) laser pulses. In this regard, shot-to-shot as well as long-term modulation stability of LCMs are crucial requirements on its application in the broadband shaping of fs pulses. In this work, we show that when LCMs are applied to broadband tailoring of fs pulses (12 fs), depending on acquisition and detection conditions, noise figures up to 7 % can be observed. Our results show that spectral phase instability is originated by the LCM. In order to understand and thus minimize such instabilities, phase-sensitive measurements based on second harmonic generation of the tailored pulse, comparison of rapid-scan and step-scan results as well as careful control of the LCM temperature were implemented. The noise figure can be decreased by a factor of ten if a rapid-scan data acquisition approach is used instead of step scan. Furthermore, the study shows that the key in maximizing pulse stability and minimizing noise effects lies in careful control of the LCM operating temperature, improving the shot-to-shot stability of the output tailored pulse by a factor of two. Based on the experimental data we developed a physical model for a deeper understanding of the influence, especially the average scheme, and the level of noise.