INFRARED-ABSORPTION OF MULTIPLE-QUANTUM WELLS - BOUND TO CONTINUUM TRANSITIONS

Optical transitions between bound and continuum states in multiple-het erojunction quantum structures are numerically investigated. In the co nduction band energy range the absorption to continuum is studied with in one-band effective-mass approximation. By changing the shape of qua ntum wells, we can tune the energy corresponding to absorption peak. W e also show how the absorption is modified in the case of annealed str uctures. The inter-subband transitions in the energy range of valence band in Si/Si1-xGex/Si quantum well are described with the help of mul tiband Luttinger-Kohn Hamiltonian. Particular attention is paid to tra nsitions to resonant states.