Designing scalable WDM optical interconnects using predefined wavelength conversion

We investigate the problem of designing scalable wavelength division multiplexing (WDM) optical interconnects with reduced hardware complexity. We present a new WDM interconnect based on the well-known three-stage Clos network. For scalability purposes, any wavelength conversion occurs between two predefined wavelengths, eliminating the need for any full- or wide-range wavelength converters. We show that the new design provides better scalability at a reduced hardware complexity compared with most of the recent best interconnect designs. We also show that the proposed interconnect admits existing routing algorithms for the three-stage space Clos network with simple extensions.