Stably joined optical tables

We present a simple and practical method for joining pneumatically floated optical tables. In order to demonstrate this method we joined two optical tables in an uncentered "T-shape", and used a Michelson interferometer to compare the stability of the entire "T-structure" versus one of its parts alone finding that they both show similar rigidity. We also found the optimal master-slave leg configuration by calculating the stress on the joint and confirmed the calculations by Michelson interferometry. The vibration damping for the "T-structure" against the unjoined tables was measured finding comparable results. This method can significantly reduce costs of large optical tables and will be useful to extend existing optical tables without manufacturer modification.