High-performance microprocessors that harness photons rather than electrons promise to make computers up to a thousand times more efficient because electrons typically move at a low fraction of the speed of light. Problem: scaling down conventional electronic microprocessors is easy; doing the same with photonic components is hard because of the difficulty of getting light to turn corners. So scientists have turned to plasmonic components, which take advantage of the unique oscillating interactions of photons and electrons on the surface of metal.
Ref: Self-Heating and Cooling of Active Plasmonic Waveguides. ACS Photonics (3 December 2015) | DOI: 10.1021/acsphotonics.5b00449
Loss compensation in plasmonic nanostructures gives a possibility to avoid problems with strong absorption in the metal and design deep-subwavelength optical components for practical applications. At the same time, pumping required for creation of population inversion produces a huge amount of waste heat, which can significantly increase the device temperature and degrade its performance. Eventually, self-heating is becoming a severe problem for active plasmonics, since it limits the maximum achievable optical gain. Here we report a comprehensive study of heat generation and transport in electrically pumped active plasmonic waveguides, in which the SPP propagation losses are compensated by gain in the adjacent semiconductor and present a strategy for their efficient cooling.