Abstract: An architecture for a fiber optic communication system that uses only two levels of switches, Tier 1 and Tier 3, is described. The architecture allows one to omit the conventional Top of Rack switch level and the conventional Tier 2 switch level while maintaining performance and throughput. The cost to construct and install the improved switch architecture is lower than the cost of the conventional architecture. There are also described a number of transceivers that are suitable for use in the architecture disclosed. The transceivers employ silicon PIC chips that include high contrast silicon waveguides ion the chip and that connect to various configurations of optical fibers. The transceivers provide enhanced switching capacity with fewer devices.