Plasmonic electro-optic modulator based on degenerate semiconductor interfaces

We present a semiconductor-based optoelectronic switch based on active modulation of surface plasmon polaritons (SPPs) at lattice-matched indium gallium arsenide (In0.53Ga0.47As) degenerately doped pn++ junctions. The experimental device, which we refer to as a surface plasmon polariton diode (SPPD), is characterized electrically and optically, showing far-field reflectivity modulation for mid-IR wavelengths. Self-consistent electro-optic multiphysics simulations of the device’s electrical and electromagnetic response have been performed to estimate bias-dependent modulation and switching times. The numerical model shows a strong agreement with the experimental results, validating the claim of excitation and modulation of SPPs at the junction, thus potentially providing a new pathway toward fast optoelectronic devices.