Processing information with conventional integrated circuits remains beset by the interconnect bottleneck: circuits made of smaller active devices need longer and narrower interconnects, which have become the prime source of power dissipation and clock rate saturation. Optical inter-chip communication provides a fast and energy-saving option that still misses a generic on-chip optical information processing by interconnect-free and reconfigurable Boolean arithmetic logic units (ALU). Considering metal plasmons as a platform with dual optical and electronic compatibilities, we forge interconnect-free, ultracompact plasmonic Boolean logic gates and reconfigure them, at will, into computing ALU without any redesign nor cascaded circuitry. We tailor the plasmon mode landscape of a single 2.6-µm 2 planar gold cavity and demonstrate the operation and facile reconfiguration of all 2-input logic gates. The potential for higher complexity of the same logic unit is shown by a multi-input excitation and a phase control to realize an arithmetic 2-bit adder.

This paper explores the nonlinear photoluminescence emitted by Indium Tin Oxide (ITO) thin layers patterned by focused gallium ion beam milling. Using tightly focused near-infrared femtosecond pulsed laser excitation, a broad up-converted luminescence spanning the visible spectrum is detected. The intensity of the luminescence follows a non-monotonous relationship with milling doses and can be related to the modification of the ITO electronic band structure by the implantation of Ga ions. The shape and the power dependence of the spectrum share strong similarities with nonlinear photoluminescence arising from metals. The results are consistent with a nonlinear luminescence process originating from the radiative decay of photo-generated hot carriers. The ther-1 mal coefficient relating the hot carrier temperature to the laser intensity is determined as a function of milling dose.