Loss compensation in long-range dielectric-loaded surface plasmon-polariton waveguides.

Loss compensation in long-range dielectric-loaded surface plasmon-polariton waveguides is theoretically analyzed when rare-earth-doped double tungstate crystalline material is used as the gain medium in three different waveguide configurations. We study the effect of waveguide geometry on loss compensation at the telecom wavelength of 1.55 μm, and demonstrate that a material gain as small as 12.5 dB/cm is sufficient for lossless propagation of plasmonic modes with sub-micron lateral confinement when using waveguide ridges with gain.