Power efficiency of 40 Gbit/s and 100 Gbit/s optical ethernet

Recently, there have been significant research and standardization efforts to specify and implement 40 and 100 Gigabit Ethernet systems (40GbE and 100GbE). The proposals for the physical layer range from parallel transmission using a number of optical fibers or a number of wavelength channels within a single fiber to serial transmission over a single wavelength channel by exploiting advanced modulation formats and high-speed data processing. Since power consumption is becoming the main limiting factor in scaling current switches, routers and data centers to very high capacities, it would be of interest to see if the proposed 40 Gbit/s and 100 Gbit/s Ethernet physical-layer transport options could contribute to reduce the total power consumption of high-performance networking and storage systems.