Rostock 2019 – scientific programme

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Q: Fachverband Quantenoptik und Photonik

Q 5: Precision Measurements and Metrology I

Q 5.8: Talk

Monday, March 11, 2019, 12:15–12:30, S SR 111 Maschb.

Bragg beam splitters with misaligned Gaussian laser beams — •Antje Neumann and Reinhold Walser — Institut Angewandte Physik, Technische Universität Darmstadt, Darmstadt, Deutschland

Atomic beam splitters are a central component of matter wave interferometers, which provide the opportunity of high-precision rotation and acceleration sensing. Potential applications range from fundamental physics to inertial navigation. In the QUANTUS free-fall experiments atom interferometry is the central method as well [1].

Beam splitters are used to prepare coherent superpositions of atomic wave packets in momentum space by transferring photon momentum from a laser field. Like optical systems matter wave devices require exact specifications and ubiquitous imperfections need to be quantified.

We analyse the aberrations of quasi Bragg beam splitters in 3D. In particular, we characterise the non-ideal behaviour due to spatial variations of the laser beam profiles and wave front curvatures, regarding realistic Gaussian laser beams instead of ideal plane waves. Especially, we study the effect of slightly decentered and tilted lasers. In addition, different temporal pulse shapes will be considered.

We present results of numerical and analytical studies of the velocity dependence of the complex reflectivity of the beam splitter and finally, we match our theory with experimental data [2].

This work is supported by the German Aeronautics ans Space Administration through grant 50 WM 1557.

[1] D. Becker et al., Nature 562, 391-395 (2018).

[2] M. Gebbe, Universität Bremen, Zarm, private communication.