Quantum technologies

Modern experiments for the investigation of cold atom ensembles require an ultra-high vacuum apparatus with a very large optical access and an accurate preservation of the state of polarization of laser beams. Typical ultrahigh vacuum cells suffer from residual stress-induced birefringence, which deteriorates the polarisation's purity [1]. In addition, birefringence gradients prevent the full compensation of birefringence. This effect effectively limits the extinction ratio to typically η > 10^-5. We recently developed an ultra-low birefringence ultra-high vacuum cell that exhibits a polarization extinction two orders of magnitude smaller than commercial vacuum cells at around η ≈ 10^-7 [2]. Besides the ultra-low birefringence, the vacuum cell features a dodecagonal geometry with double-sided antireflection coated windows (see picture). The cell is currently utilized in one of our laboratories, where we manipulate ultracold Cs atoms in two-dimensional state-dependent optical lattices.

If you are interested in our invention for commercial applications, please see our patent abstract containing also the contact to our patent advisor, PROvendis [3].