ANALYSIS OF DISTRIBUTED-FEEDBACK SEMICONDUCTOR LASER-ELECTROABSORPTION MODULATOR INTEGRATED LIGHT-SOURCE, INCLUDING GAIN-COUPLED STRUCTURE

Taking into consideration of gain coupling, characteristics such as si ngle-mode selectivity, chirping and light output efficiency of photoni c integrated circuits (PIG) integrating distributed feedback (DFB) sem iconductor lasers and electroabsorption modulators are analyzed for th e first time. Devices with conventional index-coupled (IC), quarter-wa ve-shifted (QWS) and gain-coupled (GC) DFB laser sections are calculat ed and compared. The chirping of GC-PIC is nearly the same as that of IC-PIC and QWS-PIC, hut the single-mode selectivity of GC-PIC is much better. With a [HR-AR] coating, which is advantageous for high-power o peration, GC-PIC shows a much higher probability of single-mode operat ion than IC-PIC, while QWS-PIC does not function at all.