A sequence of MEMS processing steps are used to construct a 2D optical switch on a single substrate. In a typical optical switch configuration, an array of hinged micromirrors are supported by an array of posts at a 45° angle to the input and output optical paths and positioned parallel to the substrate either above, below or, perhaps, in the optical paths. The application of a voltage between the mirror and its control electrodes switches the mirror to a vertical position where it intercepts and deflects light travelling down the optical paths. The posts are suitably oriented at a 90° angle with respect to the mirror hinges so that they do not interfere with the optical paths and, may be configured to function as baffles to reduce crosstalk between adjacent optical paths.