Recent advances in the understanding and control of cold atom systems have resulted in devices with extraordinary metrological performance. To further improve the performance in these systems, additional methods of noise reduction are needed. Here, we examine the noise reduction possible from vacuum compatible low reflection coatings in cold atom systems by characterizing a black coating and its compatibility in a Magneto-Optical Trap (MOT). We demonstrate that the commercially available PCO35® coating provides low-reflectivity surfaces that are ultra-high vacuum compatible. The reflective properties of the coating are compared to titanium, a common vacuum chamber material, and the reduction to scattered light is characterized over a range of angles and wavelengths. The outgassing properties of the coating are measured to be less than that of the vacuum system used to test the coating, which is limited to 3 × 10-8 mbar L cm-2 s-1. The coating is applied to a vacuum chamber housing a rubidium prism MOT, and its vacuum compatibility is assessed and compared to an identical non-coated system. Finally, the effect of scattered light reduction in a generalized system is explored theoretically. These results show promise for reducing background light in cold atom experiments via the use of low-reflectivity coatings.
Bibliographical noteFunding Information:
The authors would like to thank the University of Birmingham’s Physics workshop team for machining the custom vacuum chambers used in these experiments. We would also like to thank Jonathan Bass for lending us some of the lasers used for the experiment shown in Fig. 2. The authors would like to acknowledge funding from EPSRC through Grant Nos. EP/M013294 and EP/S004084/1, DSTL through Contract No. DSTLX-1000095040, and Innovate UK through the Gravity Pioneer Grant No. 104613.
© 2020 Author(s).
ASJC Scopus subject areas
- Physics and Astronomy(all)