In this paper, we present a high-resolution, simple, and versatile imaging system for single-site resolved imaging of atoms in optical lattices. The system, which relies on an adaptable infinite conjugate two-lens design, has a numerical aperture of 0.52, which can in the ideal case be further extended to 0.57. It is optimized for imaging on the sodium D2-line but allows us to tune the objective’s diffraction limited performance between 400 nm and 1000 nm by changing the distance between the two lenses. Furthermore, the objective is designed to be integrated into a typical atomic physics vacuum apparatus where the operating distance can be large (>20 mm) and diffraction limited performance still needs to be achieved when imaging through thick vacuum windows (6 mm to 10 mm). Imaging gold nanoparticles, using a wavelength of 589 nm which corresponds to the D2-line of sodium atoms, we measure diffraction limited performance and a resolution corresponding to an Airy radius of less than 0.7 µm, enabling potential single-site resolution in the commonly used 532 nm optical lattice spacing.In this paper, we present a high-resolution, simple, and versatile imaging system for single-site resolved imaging of atoms in optical lattices. The system, which relies on an adaptable infinite conjugate two-lens design, has a numerical aperture of 0.52, which can in the ideal case be further extended to 0.57. It is optimized for imaging on the sodium D2-line but allows us to tune the objective’s diffraction limited performance between 400 nm and 1000 nm by changing the distance between the two lenses. Furthermore, the objective is designed to be integrated into a typical atomic physics vacuum apparatus where the operating distance can be large (>20 mm) and diffraction limited performance still needs to be achieved when imaging through thick vacuum windows (6 mm to 10 mm). Imaging gold nanoparticles, using a wavelength of 589 nm which corresponds to the D2-line of sodium atoms, we measure diffraction limited performance and a resolution corresponding to an Airy radius of less than 0.7 µm, enabling potential single-site resolution in the commonly used 532 nm optical lattice spacing.

Review of Scientific InstrumentsMay 1, 20198 citations

High-Resolution Imaging of Cold Atoms through a Multimode Fiber

Nicolas Vitrant, Sébastien Garcia, Kilian Müller +1 more

We develop an ultracompact high-resolution imaging system for cold atoms. Its only in-vacuum element is a multimode optical fiber with a diameter of 230 $\ensuremath{\mu}\mathrm{m}$, which simultaneously collects light and guides it out of the vacuum chamber. External adaptive optics allow us to image cold $\mathrm{Rb}$ atoms with approximately 1-$\ensuremath{\mu}\mathrm{m}$ resolution over a $100\ifmmode\times\else\texttimes\fi{}100\phantom{\rule{0.2em}{0ex}}\ensuremath{\mu}{\mathrm{m}}^{2}$ field of view. These optics can be easily rearranged to switch between fast absorption imaging and high-sensitivity fluorescence imaging. This system is particularly suited for hybrid quantum-engineering platforms where cold atoms are combined with optical cavities, superconducting circuits, or optomechanical devices restricting optical access.We develop an ultracompact high-resolution imaging system for cold atoms. Its only in-vacuum element is a multimode optical fiber with a diameter of 230 $\ensuremath{\mu}\mathrm{m}$, which simultaneously collects light and guides it out of the vacuum chamber. External adaptive optics allow us to image cold $\mathrm{Rb}$ atoms with approximately 1-$\ensuremath{\mu}\mathrm{m}$ resolution over a $100\ifmmode\times\else\texttimes\fi{}100\phantom{\rule{0.2em}{0ex}}\ensuremath{\mu}{\mathrm{m}}^{2}$ field of view. These optics can be easily rearranged to switch between fast absorption imaging and high-sensitivity fluorescence imaging. This system is particularly suited for hybrid quantum-engineering platforms where cold atoms are combined with optical cavities, superconducting circuits, or optomechanical devices restricting optical access.

arXiv:2012.09073Physical Review AppliedJun 17, 20212 citations

Nonlinear photon-atom coupling with 4Pi microscopy

Yue-Sum Chin, Matthias Steiner, Christian Kurtsiefer

Implementing nonlinear interactions between single photons and single atoms is at the forefront of optical physics. Motivated by the prospects of deterministic all-optical quantum logic, many efforts are currently underway to find suitable experimental techniques. Focusing the incident photons onto the atom with a lens yielded promising results, but is limited by diffraction to moderate interaction strengths. However, techniques to exceed the diffraction limit are known from high-resolution imaging. Here we adapt a super-resolution imaging technique, 4Pi microscopy, to efficiently couple light to a single atom. We observe 36.6(3)% extinction of the incident field, and a modified photon statistics of the transmitted field-indicating nonlinear interaction at the single-photon level. Our results pave the way to few-photon nonlinear optics with individual atoms in free space.Implementing nonlinear interactions between single photons and single atoms is at the forefront of optical physics. Motivated by the prospects of deterministic all-optical quantum logic, many efforts are currently underway to find suitable experimental techniques. Focusing the incident photons onto the atom with a lens yielded promising results, but is limited by diffraction to moderate interaction strengths. However, techniques to exceed the diffraction limit are known from high-resolution imaging. Here we adapt a super-resolution imaging technique, 4Pi microscopy, to efficiently couple light to a single atom. We observe 36.6(3)% extinction of the incident field, and a modified photon statistics of the transmitted field-indicating nonlinear interaction at the single-photon level. Our results pave the way to few-photon nonlinear optics with individual atoms in free space.

arXiv:1705.10173Nature CommunicationsOct 25, 201725 citations

\mathrm{Rb}

atoms with approximately 1-$\ensuremath{\mu}\mathrm{m}$ resolution over a $100\ifmmode\times\else\texttimes\fi{}100\phantom{\rule{0.2em}{0ex}}\ensuremath{\mu}{\mathrm{m}}^{2}$ field of view. These optics can be easily rearranged to switch between fast absorption imaging and high-sensitivity fluorescence imaging. This system is particularly suited for hybrid quantum-engineering platforms where cold atoms are combined with optical cavities, superconducting circuits, or optomechanical devices restricting optical access.