Optical absorption and carrier-induced bleaching effect in quantum wire and quantum box structures

The optical absorption spectra of quantum wires and boxes are studied theoretically to evaluate the carrier-induced bleaching effect. It is found that the absorption coefficients of these highly confined systems (HCSs) and their changes with the introduction of carriers can be far greater than those of less-confined systems (LCSs) such as quantum wells (films) and bulk semiconductors. In addition, the carrier-induced bleaching effect of HCS is found to remain very high at room temperature while that of LCS is substantially weakened by the thermal distribution of carriers.