An optical switch network (10) which includes a plurality N of cascaded optical switching stages, each mth one of the switching stages including 2 Mach-Zehnder interferometers (12) where m = 1 through N. The input port of the Mach-Zehnder interferometer (12) of the first one of the optical switching stages receives an optical input signal, and the 2 Mach-Zehnder interferometers (12) of the Nth one of the optical switching stages provide a total of 2 output ports. Each of the Mach-Zehnder interferometers is preferably an unbalanced Mach-Zehnder interferometer, and the optical input signal preferably has a wavelength which is a selected one of 2 selectable wavelengths. Also disclosed is an optical time delay network (30) comprised of an optical switch network as described above, and a plurality 2 of optical delay lines of different lengths coupled to respective ones of the 2 output ports of the Nth one of the optical switching stages, each of the optical delay lines (30) being comprised of an optical waveguide having a light reflecting end.