A novel vertical-cavity surface-emitting laser with semiconductor/superlattice distributed Bragg reflectors

Taking into account the tunneling effect of the superlattice, the authors present for the first time a vertical-cavity surface-emitting laser with AlAs[GaAs-AlAs] semiconductor/superlattice distributed Bragg reflectors (DBRs). The structure of a 19-period-AlAs (73.3 nm)-18.5-pair [GaAs (3.0 nm)-AlAs (0.7 nm)] DBR was grown on an n-GaAs (100) substrate by molecular beam epitaxy, and the device was fabricated by using a modified technique of proton implantation. It was found from the experiments that the peak reflectivity of the DBR is as high as 99.7%, the central wavelength is at about 840 nm, and the reflection bandwidth is wide up to 90 nm. A 20 × 20 μm² square mesa on the top of the DBR was made by the wet chemical etching method to measure the series resistance of the devices. It can be seen that more than a third of them are within 20-30 Ω that lead to ideal optical characteristics, low dissipated power, and reliability-some of the most important factors for the devices to be used in a number of applications in the future.