The design of electroabsorption modulators with negative chirp and very low insertion loss

Electroabsorption modulators (EAMs) with negative chirp and very low insertion loss are numerically designed with asymmetric intra-step-barrier coupled double strained quantum wells (AICD-SQWs) based on InGaAlAs material. For this purpose, the electroabsorption coefficient is calculated over a range of wells layer strain from compressive (CS) to tensile (TS). The chirp parameter and insertion loss for TE input light polarization are evaluated from the calculated electroabsorption spectra, and their Kramers-Krönig transformed refractive index changes. The results of the numerical simulation show that the best range of left and right wells strain for EAMs based on AICD-SQWs with negative chirp and very low insertion loss are from 0.032% to 0.05% (TS) and −0.52% to −0.50% (CS), respectively. (semiconductor devices)