The design of the n++-InGaAs/р++-InGaAs/р++-InAlGaAs tunnel junction (TJ) for 1.55 μm range vertical-cavity surface-emitting lasers (VCSELs), developed by wafer fusion technique of InAlGaAsP/InP optical cavity with AlGaAs/GaAs distributed Bragg reflectors is proposed and realized. The presence of oxidation-resistant InGaAs layers allows the use of molecular-beam epitaxy at all stages of the heterostructure fabrication, including for regrowth of the TJ surface relief. In the case of using the n++-InGaAs/р++-InGaAs/р++-InAlGaAs TJ, a noticeable increase in the internal optical losses compared to the n++/р++-InAlGaAs TJ design was not obtained. The increase in internal optical loss in lasers can be avoided due to Burshtein-Moss effect in n++-InGaAs layers and thickness minimization of р++-InGaAs layer. As a result, the characteristics of fabricated lasers are comparable with characteristics of VCSELs with n++/p++-InAlGaAs TJ with a similar level of mirror losses.
Quasi-Continuous Operation of 1.55- μm Vertical-Cavity Surface-Emitting Lasers by Wafer Fusion
