A Compact & Versatile Cavity Machine for Optically Levitated Nanoparticles

Dominik Windey, René Reimann, Erik Hebestreit, Lukas Novotny
Photonics Laboratory, ETH Zurich, Switzerland

The prospects of building highly sensitive detectors and to learn about quantum mechanics and thermodynamics on the mesoscopic scale have led to a growing interest in the field of cavity optomechanics [1]. In our experiment, we plan to couple an optically levitated nanoparticle to a high finesse, small mode volume microcavity. Our hybrid system will be operated outside the resolved sideband regime, thereby enabling fast and efficient detection of the sphere's center-of-mass motion. In conjunction with our well-established feedback scheme [2] this technique will boost the capability of active feedback cooling to achieve the sphere's ground state of motion. Here we present our technical progress of building a compact and versatile system. If possible we utilize intrinsically stable fiber connections. A home-made trapping lens assembly as well as a home-made quadrant photodiode (QPD) help to compactifiy and to increase the stability of the system. Our first measurement cavity is build using passive and active stabilization and noise cancellation methods. The overall design guarantees good optical access to the trapped nanoparticle.

[1] M. Aspelmeyer, et al., Rev. Mod. Phys. 86, 1391-1452 (2014)     
[2] J. Gieseler, et al., Phys. Rev. Lett. 109, 103603 (2012)