Hannover 2016 – wissenschaftliches Programm

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

MO: Fachverband Molekülphysik

MO 14: Posters 3: Novelties in Molecular Physics: Theory of Molecular Dynamics, Collisions and Energy Transfer, and Experimental Techniques

MO 14.12: Poster

Mittwoch, 2. März 2016, 16:30–19:00, Empore Lichthof

Laser absorption spectroscopy of iodine: 915 nm to 985 nm in a single scan — •Christian Nölleke, Stephan Falke, Christoph Raab, and Rudolf Neuhaus — TOPTICA Photonics AG, Lochhamer Schlag 19, Gräfelfing/München, Germany

Iodine gas cells serve as frequency reference for lasers thanks to the good understanding of their rich molecular spectrum. This is particularly true for the wavelength range 500 nm to 900 nm, where the theoretical model of the B-X system and experimental findings agree on a level of a few MHz. Hence, iodine cells provide frequency references with a line spacing of typically a few GHz only.

In order to extend this knowledge towards longer wavelengths, a deeper understanding of the A-X system of iodine is required. Recent developments in laser technology enable high-resolution spectroscopy with unprecedented ease. In this work, we record absorption spectra with a 75 cm long iodine cell, in which vapor pressure and temperature of the molecular gas is controlled independently. We utilize the vast mode-hope-free tuning range of the DLC CTL developed within our company to investigate the distribution of observable molecular lines as well as their signal-to-noise ratio in the range 915 nm to 985 nm. Moreover, for selected lines, we perform at saturation absorption spectroscopy using the fine-tuning of the laser. This experiment is an important step towards a detailed theoretical model of the A-X system and hence a good frequency reference in this range.