Compensation for propagation loss by semiconductor gain medium in MSM plasmonic waveguide

For further study of the gain compensation of plasmonic waveguide for the propagation loss in the range of ultraviolet wavelengths, the metal-semiconductor-metal(MSM) plasmonic waveguide structure embedded with semiconductor gain medium was proposed and designed in this article. Based on the finite difference time-domain(FDTD) method, the dependences of propagation loss and effective refractive index on the geometrical parameters of the waveguide structure were analyzed. In addition, the condition for lossless propagation in using II-VI semiconductor material ZnO as the gain medium was investigated. The simulation results show that the lossless gain-assisted surface plasmon polartions propagation in MSM can be achieved for ultraviolet wavelengths when the width of the semiconductor core is 80 nm; and the propagation loss is much less than the gain obviously as the width of ZnO is greater than 80 nm. This achievement can realize the propagation amplification of surface plasmonic polartions, which provides the theoretical support for surface plasmon polariton nano-laser technologies.