Design issues in free-space digital optics

The authors have detailed some of the ways in which the specification of each component of a digital free-space photonic switch are coupled. Such systems may ultimately be capable of providing massive connectivity of high speed signals. The production of large 2-dimensional arrays of optical devices which are cascadable has enabled a new technology. This is a recent development. Consequently, only a few free-space digital optical circuits have been constructed. The systems operate with a performance well below that achievable with conventional electronics. However, their construction validates the confident prediction of the feasibility of more viable full scale systems. It also enables the assessment of both components and architectures in a test-bed system, providing feedback to improve individual aspects of the overall system