LASING IN SUBMONOLAYER INAS ALGAAS STRUCTURES WITHOUT EXTERNAL OPTICAL CONFINEMENT/

Structures having a set of planes with submonolayer InAs inclusions in an AlGaAs matrix were fabricated and studied. Lasing was observed as a result of optical excitation. It is shown that lasing takes place vi a the ground state of excitons localized at InAs islands and may be ac hieved without external optical confinement of the active region by wi de-gap layers of lower refractive index. The low threshold excitation density shows that these structures may be used to develop low-thresho ld injection lasers in the visible range, exciton waveguides, and self -contained microcavities. (C) 1998 American Institute of Physics.