CALCULATIONS OF INTERSUBBAND OPTICS FOR SYMMETRICAL AND ASYMMETRIC QUANTUM-WELLS, WIRES AND DOTS

We present calculations of intersubband optics in quantum dots and qua ntum wires. The aim is to compare the linear and nonlinear optical pro perties of these structures with quantum wells for the n-doped case. W e have used a one-band k . p model to describe the electronic states. As expected, the polarization selection rules are relaxed in the sub-t wo-dimensional cases. The absorption coefficients at T = O K are compa red and are found to be similar in magnitude. Second-order nonlinearit y is also calculated for the asymmetric structures. It is found that t he doubly resonant nonlinear susceptibilities for the wire and dot str uctures are generally smaller than for the corresponding quantum well. On the other hand, the second-harmonic spectra are very similar.