Spectral characteristics of an InP/InGaAs distributed absorbing Bragg reflector

Abstract
An InP/In0.53Ga0.47As distributed absorbing Bragg reflector is investigated by reflectance and group-delay-time spectroscopy. The measured reflectance is suppressed and shows a minimum at the low-wavelength side of the high-reflectance band. This suppression of reflectance is due to an enhancement of optical absorption. The enhancement of optical absorption originates from an increase in the overlap of the optical field with the absorbing InGaAs layers since an intense optical field is confined near the surface in the spectral range of the enhancement.