Coupling between lattice and waveguide modes in semiconductor plasmonic crystal lasers

Semiconductor-based plasmonic crystal lasers (PCLs) have narrow linewidth, small divergence angle, excellent thermal stability, and great potential for ultra-high-speed communications. The underlying mechanism and lasing modes for their operation is unfolded in this work. We find that the waveguide mode coupling with the surface plasmonic mode plays an essential role in the semiconductor-based PCLs. The simulation and experimental data reveal that the cooperation of the dielectric layers and the metallic nano-pillar array gives the needed resonant mode of high-quality factor. The mode coupling strength has to be properly designed to make these intriguing devices working.