Free-space optical interconnections offer a means to alleviate many high speed, high density communications problems in digital systems. The realization of this new technology involves the application of many classical optical testing techniques, as well as the development of several novel tools and techniques. We describe the design and implementation of a free-space optically interconnected switching fabric, and the fabrication and testing techniques involved. The lenses, polarizing beam-splitters, lasers, and diffractive optics used in the experiment were tested for optical transmission efficiency and uniformity, and wavefront quality.