  Using criteria of bandwidth and energy consumption for signal guiding and
processing, system-level figures of merit for both passive and active plasmonic
circuit components are introduced, benchmarking their performance for the
realisation of high-bandwidth optical data communication on a chip. The figure
of merit for passive plasmonic interconnects has been derived in terms of the
system level performance of the plasmonic circuitry, emphasising the bandwidth
and power consumption densities. These parameters are linked to the local
waveguide characteristics, such as the mode propagation length, bend radius and
mode size. The figure of merit enables a comparison of the main types of
plasmonic waveguides and can serve as a benchmark for future designs of
photonic integrated circuits. A figure of merit for active photonic- or
plasmonic-based electro-optical, thermo-optical and all-optical modulators is
also derived to reflect the same benchmarking principles. A particular emphasis
is made on establishing a practically oriented benchmark where the integral
performance of the circuit, not the size or energy consumption of individual
components, plays the defining role.
