Abstract
We examine the sensitivities of the intrastep-quantum-well (IQW) structure with an InGaAs well to the thickness and composition variations. With the layer variations into account, we evaluate the changes in absorption coefficient as a function of electric field and the subsequent transfer functions of the electroabsorption modulator. It is concluded that the examined IQW structure is rather sensitive to the thickness variation but is robust to the composition variation. This work suggests that the thickness control is very important in actually growing the IQW structure to obtain the desired performance with the IQW.