Optical interconnects replace hardwire: Light promises to relieve bottlenecks in electric interconnections from cabinet to cabinet, board to board, IC to IC — and even within chips

As the geometries of very large-scale integrated (VLSI) chips grow smaller and denser, and as computations become faster and more complex, the capacity of electric circuits is being outstripped. The connections simply cannot handle electric signals fast enough and reliably enough. In advanced systems, the power drain and the sheer numbers of the wires linking the chips, and linking the circuit boards, is prohibitive. Connecting circuits by light instead of by electric signals promises relief.