Optical setup for a two-dimensional tweezer array with independently adjustable columns for neutral atom quantum computing

We present an optical design concept to create a two-dimensional tweezer array for neutral atom quantum computing. The first part of the setup splits the four input laser beams into 20 individual beam lines that correspond to the columns of the tweezer array. A combination of an acousto-optic deflector (AOD) and a suitable imaging lens for each beam line creates a magnified image of the one-dimensional columns in the tweezer array with a spacing of less than 200 μm. The spacing between the 20 columns is reduced to this value as well to achieve a spot array with an equidistant spacing in both axes. This is done successively in four steps by using a combination of one discrete mirror cascade and three mirror cascades integrated into monolithic mirror arrays. The final tweezer array with a spacing of 3.5 μm is then created by a two-stage telecentric demagnifying lens group. Unlike other approaches to create a two-dimensional tweezer array (e.g. crossed AODs), the use of a separate AOD for each column allows for an independent adjustment of the spacings within each column and thus a flexible adjustment of the local interaction of neighboring atoms. A raytracing analysis demonstrates that the whole setup produces a telecentric and diffraction-limited image of 20 × 100 spots in the following vacuum chamber.