Crossed optical cavities with large mode diameters

Abstract

We report on a compact, ultrahigh-vacuum compatible optical assembly to create large-scale, two-dimensional optical lattices for use in experiments with ultracold atoms. The assembly consists of an octagon-shaped spacer made from ultra-low-expansion glass, to which we optically contact four fused-silica cavity mirrors, making it highly mechanically and thermally stable. The mirror surfaces are nearly plane-parallel which allows us to create two perpendicular cavity modes with diameters $\sim$1 mm. Such large mode diameters are desirable to increase the optical lattice homogeneity, but lead to strong angular sensitivities of the coplanarity between the two cavity modes. We demonstrate a procedure to precisely position each mirror substrate that achieves a deviation from coplanarity of $d=1(5)$ $\mu$m. Creating large optical lattices at arbitrary visible and near infrared wavelengths requires significant power enhancements to overcome limitations in the available laser power. The cavity mirrors have a customized low-loss mirror coating that enhances the power at a set of relevant wavelengths from the visible to the near infrared by up to three orders of magnitude.

4 pages, 4 figures, 1 page supplemental material

References in corpus (6)

• Advanced LIGO
• Cavity QED with a Bose-Einstein condensate
• Supersolid formation in a quantum gas breaking continuous translational symmetry
• Tunable-range, photon-mediated atomic interactions in multimode cavity QED
• Atom interferometry in an optical cavity
• Monolithic bowtie cavity traps for ultra-cold gases