A new splitter-and-delivery (SAD) switch having multicasting capability is proposed. It is best implemented in a single silicon board using planar silica waveguide technology. Less than -40-dB crosstalk is achievable by an auxiliary action of the optical gate. Three optical cross-connect architectures employing the SAD switch are proposed. They are strictly nonblocking and have multicasting capability. Furthermore, they have wavelength or fiber modular structures and are expandable when the number of the fibers and the wavelengths increase a few or by a few times. The expanding method and other important issues are discussed in detail.