Design considerations of intra-step SiGeSn/GeSn quantum well electroabsorption modulators

Theoretical investigation of electro-absorption modulators in the mid-infrared range (>∼2 μm) is performed using asymmetric intra-step quantum wells based on Ge1−η1Snη1/Ge1−η2Snη2 heterostructures with SiGeSn outer barriers. After exploring parameter space Sn content difference and width ratio intra-layers, a linear much larger Stark shift realized, compared to that square well, without an increase total structure width. A modulator optimized well 12 nm theoretically predicted have both peak per unit applied field absorption change than device. By analyzing device performance two figures merit: (1) (2) squared, taking 10 dB extinction ratio, 44% higher bandwidth volt 46% lower power consumption bit are achieved well. Although swing voltage for can be reduced by on-set could improved, we found zero still retains its advantages when which uses 0.5 V voltage.