Optical gain and excitonic processes in widegap semiconductor quantum wells

The dominant role of the strong electron-hole Coulomb correlations in wideg ap II-VI semiconductor quantum well heterostructures is illustrated by sele ctively highlighting key phenomena studied in experiments encompassing ZnSe -based QWs. These include gain and stimulated emission at low temperatures from excitonic molecules, excitonic enhancements to gain in room temperatur e green-blue diode lasers, and light-matter interaction in vertical microca vity lasers.