Separate-confinement-oxidation vertical-cavity surface-emitting laser structure

Abstract

In the present paper, a comprehensive self-consistent three-dimensional model is used to analyze physical aspects of the operation of oxide-confined vertical-cavity surface-emitting diode lasers (VCSELs) and to optimize their structures. The impact of the built-in radial confining mechanisms created by oxide apertures, i.e., the influence of their diameters and localizations on radial confinements of both the current injection into VCSEL active regions and electromagnetic fields of successive cavity modes, has been investigated. Basically, there are two extreme cases: the index-guided (IG) VCSELs with the aperture localized at the antinode position of the optical standing wave, characterized by a very low lasing threshold but exhibiting rather poor mode selectivity, and the gain-guided (GG) VCSELs with the aperture shifted to the node position, ensuring usually the single-fundamental-mode operation, but at the expense of much higher lasing threshold. In the present paper, the separate-confinement-oxidation VCSEL structure has been proposed exhibiting simultaneously advantages of both the IG VCSELs (the low lasing threshold) and the GG ones (the single-fundamental-mode operation).

Sacrificial Al0.8Ga0.2As etching for microstructures in integrated optoelectronic devices

“…Selective lateral oxidation of high Al content Al x Ga 1−x As has been utilized in VCSELs as current and optical mode confining apertures. [4][5][6] The characteristics of the laterally oxidized Al x Ga 1−x As have been reported in many papers. [7][8][9] However, for the Al x Ga 1−x As sacrificial layers, the lateral wet-etching kinetics of Al x Ga 1−x As has not yet been focused on.…”

Strong modes discrimination and low threshold in cw regime of 1300 nm AlInGaAs/InP VCSEL induced by photonic crystal

“…Hence, the spatial distributions of all material parameters are determined on the basis of the chemical compositions of the structure layers taking into account the 3D distributions of temperature, current density and carrier concentration within the whole VCSEL's volume. The details of the interactions between the different parts of our model are given in [19]. We assume in our analysis that etching through the active region does not introduce additional carrier losses.…”

Comparative analysis of lasing performance of oxide-confined and proton-implanted vertical-cavity surface-emitting diode lasers

“…for relatively small output powers only, because of increasingly non-uniform current injection into larger active regions [10]. On the other hand, GG OC VCSELs are known to ensure SFM operation for distinctly larger active regions and less divergent output beams than IG ones but it is usually achieved at the expense of much higher lasing thresholds [9]. Therefore, depending on the VCSEL application under consideration, either IG or GG OC VCSEL configurations may be intentionally used.…”

“…Therefore the oxide aperture is always funnelling the current flow, in particular from ring-shaped contacts towards the centrally located active regions, whereas the impact on radiation fields of this very thin layer depends on its position. When the aperture is localised at the anti-node position of the optical standing wave within a laser cavity (indexguided (IG) VCSELs), radial confinement of radiation fields is very large but it almost disappears-when the aperture is shifted to the analogous node position (gain-guided (GG) VCSELs) [9].…”