INTRABAND OPTICAL-ABSORPTION IN SEMICONDUCTOR COUPLED QUANTUM DOTS

In the framework of effective mass envelope function theory, absorptio n coefficients are calculated for intraband (intersubband in the condu ction band) optical transition in InAs/GaAs coupled quantum dots. In o ur calculation the microscpic distributon of the strain is taken into account. The absorption in coupled quantum dots is quite different fro m that of superlattices. In superlattices, the absorption does not exi st when the electric vector of light is parallel to the superlattice p lane (perpendicular incident). This introduces somewhat of a difficult y in fabricating the infrared detector. In quantum dots, the absorptio n exists when light incident along any direction, which may be good fo r fabricating infrared detectors.