On the optimization of InGaAs-InAlAs quantum-well structures for electroabsorption modulators

Several InGaAs-InAlAs multiple quantum-well structures grown by metalorgani c vapor phase epitaxy (MOVPE), with various Ga content and quantum-well wid th, have been investigated for electroabsorption modulators (EAM's). The li ght-hole heavy-hole splitting, the chirp parameter, the insertion loss and the figure of merit Gamma Delta alpha/F of the different InGaAs-InAlAs stru ctures have been evaluated with photocurrent, photoluminescence, absorption and X-ray measurements, It was then possible to experimentally study the i nfluence of different parameters of the multiple quantum-well structures on the device performance. The use of tensile strained barriers are believed to be responsible for the improvement in the figure of merit, Structures wi th unresolved light-hole and heavy-hole transitions, with negligible chirp, with adequate insertion loss and with extremely high values for Gamma Delt a alpha/F have been obtained, however, not simultaneously.