Investigation of micrometre scale parabolic mirrors for use as single atom quantum registers

Arrays of refractive microlenses, with diameters on the order of hundreds of micrometres, have been the subject of much research in the applied physics community. Recently, arrays of optical dipole traps, with 50 mum separation, each containing on the order of 100 laser cooled atoms, have been created. This state-of- the-art experiment, combining microfabrication and atom physics, has been proposed as the basis for a quantum simulator. Refractive microscopic elements are constrained by certain limitations that will hinder their development to smaller scales. This paper presents engineered, reflective, parabolic micromirrors, with diameters of 10 mum, that provide many of the features of microlenses but simultaneously circumvent chromatic and spherical aberrations as well as scaling issues of the lens arrays. Optical interrogation of the focal plane of the mirror array is achieved using a modified confocal microscope. Additional aspheric elements allow the illumination of the sample in reflection mode with a collimated laser. Experimental results are compared with a paraxial propagation model including full coherent modal decomposition of Gaussian beams.