Gain-assisted propagation of surface plasmon polaritons using electrically-pumped quantum wells as active medium

Gain-assisted surface plasmon polaritons (SPPs) propagation is realized by electrical pumping the InGaAsP quantum wells (QWs) beneath the metal waveguide with asymmetric configuration. The long-range and short-range mode SPPs are analyzed theoretically and observed experimentally under different levels of current injection. It is demonstrated that among the complex SPP-coupled emission mechanisms, the short-range SPP is supported by stimulated amplification (SA) in electrically-pumped QWs, and increases robustly to as 1.6 times of the long-range mode SPP in output power over a travelling distance of 80µm. This stimulated SPP emission can be adopted for the minimization of the electrically controlled optical modulator.