Heidelberg 2015 – wissenschaftliches Programm
A 35.8: Poster
Donnerstag, 26. März 2015, 17:00–19:00, C/Foyer
A power stabilized UV laser system for cooling trapped Be+ ions — •Stefanie Feuchtenbeiner1, Lisa Schmöger1,2, Oscar O. Versolato1,2, Alexander Windberger1, Matthias Kohnen2, Piet O. Schmidt2,3, and José R. Crespo López-Urrutia1 — 1MPI für Kernphysik, Saupfercheckweg 1, 69117 Heidelberg — 2PTB, Bundesallee 100, 38116 Braunschweig — 3Institut für Quantenoptik, Leibniz Universität Hannover, Welfengarten 1, 30167 Hannover
Cold, precisely localized highly charged ions (HCIs) are of particular interest for metrology and investigations of fundamental physics. Cold HCIs are prepared by means of sympathetic motional cooling, since direct laser cooling is not possible due to a lack of suitable laser transitions. 9Be+ is the cooling ion of choice here, since it can be co-trapped with HCIs in a cryogenic linear Paul trap. The Doppler cooling laser drives the 2S1/2 - 2P3/2 transition in 9Be+ at 313 nm. Its design is based on , generating the sum frequency of 1051 nm and 1550 nm from two fiber lasers in a PPLN crystal with quasi-phase matching followed by cavity-enhanced second harmonic generation in a BBO crystal stabilized by a Hänsch-Couillaud lock. Time-dependent measurements of fluorescence intensities and efficient laser cooling require a stable output power at 313 nm. For this purpose, two setups working on different time scales have been implemented. The first one compensates slow power drifts at 626 nm using a motorized λ/2-waveplate and a Glen-α-polarizer, and the second one suppresses fast power fluctuations at 313 nm with an acousto-optic modulator as key element.
 A. C. Wilson et al., Appl. Phys. B 105 (2011)