Optical Properties Of Strained-layer Inas/gaas Quantum Wells In Hetero N-i-p-i Structures

Semiconductor lasers with strained-layer InAs/GaAs active regions offer the possibility of low thresholds as well as lasing in the 900 nm - 1000 nm range. On the other hand, there have been very few studies of semiconductor materials that would be suitable as all-optical modulators for these lasers. Toward this end, we have performed the first studies of the optical properties of InAs/GaAs layers imbedded in a GaAs doping superlattice. We also demonstrate the usefulness of n-i-p-i structures for measurements of electroabsorption without the need to fabricate external contacts, in fact, without any material processing beyond the initial epitaxial growth. Furthermore, it is shown that electroabsorption is an extremely sensitive diagnostic which can be used to study the optical properties of new quantum structures.