Angle-dependent photocurrent spectroscopy of oxide-apertured vertical-cavity surface-emitting lasers during aging

Abstract

Aging properties of oxide-apertured vertical-cavity surface-emitting lasers have been analyzed by photocurrent (PC) measurements at room temperature. We demonstrate that this method allows an analysis of the aging process and provides insight into degradation mechanisms occurring during operation of these devices. By changing the angle of incidence in the PC experiment the energy positions of the top mirror features shift to higher energy while the excitonic transitions do not change. Thus, angle dependent PC spectra reveal both the appearance of defect bands located in the intrinsic region of the device as well as modifications of the top mirror transmission upon aging.