Abstract

The recent proof-of-concept demonstration of a blue-green diode laser in 1991 [1],[2] relied in part on the useful optical properties of the (Zn,Cd)Se/ZnSe and (Zn,Cd)Se/Zn(S,Se) quantum wells. These included large exciton effects to room temperature and beyond [3], a particularly unusual circumstance in wide gap II-VI semiconductors, given the large exciton-LO phonon interaction. However, due to quantum confinement, the binding energy in a ZnCdSe QW can exceed the LO-phonon energy so that excitons can in principle dominate also spontaneous emission to device temperatures. So far, most of the characterization of the new diode lasers has been performed at T = 77K, a temperature where the 2D excitons are particularly robust. The role of excitons in providing gain has been argued by us to be a physical reality in the ZnCdSe/ZnSe system [4], a feature which takes additional potential significance in terms of future diode laser design and development.

© 1993 Optical Society of America