NORMAL INCIDENCE INTERSUBBAND TRANSITIONS IN SI-DOPED INGAAS MULTIPLE-QUANTUM WELLS

Angle- and polarization-resolved infrared techniques have been used to study the polarization selection rules of intersubband transitions in Si-doped InGaAs multiple quantum wells (MQWs). Intersubband transitio ns are found to be active for light, polarized both parallel and perpe ndicular to the MQW plane, and to show a strain dependent splitting be tween the corresponding transition energies. Previously reported inter subband data measured in the Brewster angle configuration for the same lattice-matched and strained Si-doped InGaAs MQWs were also reproduce d.