Long working distance objective lenses for single atom trapping and imaging.

We present a pair of optimized objective lenses with long working distances of 117 mm and 65 mm, respectively, that offer diffraction limited performance for both Cs and Rb wavelengths when imaging through standard vacuum windows. The designs utilise standard catalog lens elements to provide a simple and cost-effective solution. Objective 1 provides NA = 0.175 offering 3 µm resolution whilst objective 2 is optimized for high collection efficiency with NA = 0.29 and 1.8 µm resolution. This flexible design can be further extended for use at shorter wavelengths by simply re-optimising the lens separations.