Analysis of surface emitting distributed-feedback quantum cascade laser based on a surface-plasmon waveguide
基于表面等离子波导的面发射分布反馈量子级联激光器的分析

An analysis of a surface emitting distributed-feedback quantum cascade laser (DFB QCL) based on a surface-plasmon waveguide is presented. The second-order grating realized by the sole patterning of the top metal provides strong feedback. The analysis is based on a coupled-mode theory derived from exact Floquet-Bloch solutions of the infinite periodic structure. The surface outcoupling efficiency and threshold gain for the optimized device design are 43% and 12 cm--1, respectively, which represent great improvements on the conventional dielectric waveguide based DFB QCL with typical values of 17.5% and 20 cm-1.