Effects of inhomogeneous broadening on reflection spectra of Bragg multiple quantum well structures with a defect

The reflection spectrum of a multiple quantum well structure with an inserted defect is considered. The defect is characterized by the exciton frequency vd different from that of the host’s wells. Effects of both homogeneous g and inhomogeneous broadenings D on a modification of the reflection spectrum caused by the defect are studied. In the case when the penetration length at the frequency vd is smaller than the length of the system, the modification of the spectrum is quite sharp and is noticeable up to very high values of D . Moreover, the position of the minimum of the reflection is shifted and this shift leads to a suppression of the effect of inhomogeneous broadening. This results in a significant drop of the reflection. A method of measuring g and D from a single reflection spectrum is suggested.