Electroluminescence of unoxidized 847 nm vertical cavity surface-emitting laser with AlAs/Al0.22Ga0.78As distributed Bragg reflectors
We present the electroluminescence spectra of an in-house grown and fabricated unoxidized vertical cavity surface-emitting laser (VCSEL) using molecular beam epitaxy (MBE). The VCSEL device is composed of asymmetric pairs of top and bottom aluminum arsenide/aluminum gallium arsenide (AlAs/Al0.22Ga0.78As) distributed Bragg reflecting (DBRs) mirrors with gallium arsenide GaAs/AlGaAs active region. Fabricated device are patterned into cylindrical mesas where several pairs of the top DBR were etched to investigate the quality of the underlying layers. Successful incorporation of the DBR is confirmed through the presence of Fabry-Perot modes. The observed emission peak at 847 nm falls within the stop-band range with a full width at half maximum (FWHM) of 4.4nm. The corresponding peak can also be observed in the photocurrent spectra with FWHM of 5.3nm. Red-shifting of the electroluminescence peak is apparent with increasing injection current and may result from induced heating of the device.