Degradation mechanism of 1310nm vertical cavity surface emission laser

Abstract

1310nm long-wavelength vertical-cavity surface-emitting lasers (VCSELs) have a wide application prospect in optical data transmission over long distances, in particular for hybrid integration with silicon photonics. With the wide application of 1310nm VCSEL, the reliability requirement is becoming more and more high. In this paper, the degradation mechanism of 1310nm VCSEL is studied by accelerated stress aging experiment. The device accelerates aging for 4000 hours at 8 mA, the maximum output power decreases by 0.04 mW, and the power saturation current and V-I curve remain basically unchanged. Leakage current of the device increases and reverse bias breakdown voltage decreases. Current noise power spectral density of the device is an order of magnitude higher than before aging. In addition, the device with degraded performance is characterized by optical emission microscopy. When the device is forward biased, dark spot defect is found on the edge of the light-emitting hole of the device after burnin. The internal topography of the device is characterized by FIB-SEM, and the oxide layer warpage is found. This is due to the increase of heat inside the device and the increase of stress in oxide layer, resulting in degradation of device’s performance.