Oxide Confinement Research Articles

Size effects in small oxide confined vertical-cavity surface-emitting lasers

Data are presented on small area vertical-cavity surface-emitting lasers with lateral sizes ranging from 5 to 1 μm that use both oxide confinement and a high-contrast distributed Bragg reflector as the upper mirror. Optical loss becomes appreciable for device sizes less than 3 μm in diameter, and is analyzed through measurements of threshold, differential output efficiency, and the far-field radiation patterns. The results suggest that loss of optical confinement occurs for thin apertures and small device sizes.

Oxide-confined vertical-cavity laser with additional etched void confinement

A vertical-cavity surface-emitting laser that incorporates oxide confinement with additional etched void photon confinement is described. A room-temperature continuous-wave threshold of 75 µA for a 3.5 µm-diameter lateral device size is achieved.

Lasing characteristics of low-threshold oxide confinement InGaAs-GaAlAs vertical-cavity surface-emitting lasers

Some lasing characteristics of index-guided InGaAs-GaAlAs vertical-cavity surface-emitting lasers (VCSEL's) with a native oxide confinement structure, which produced a low threshold current of 70 /spl mu/A, are presented. It was found that nonradiative recombination was reduced and the estimated surface recombination velocity was almost negligible. The oxidation process was uniform to produce low threshold devices while the oxidation rate was dependent on the doping or composition of DBR's. >

Characteristics of thermal stresses in Al(Cu) fine lines. II. Passivated line structures

The effects of oxide confinement on the thermal stress and yield behavior of passivated Al(Cu) line structures have been studied as a function of linewidth to submicron dimensions using a bending-beam technique. Principal stresses in the passivated line structures were deduced based on a micromechanical analysis of the curvatures of periodic line structures with lines oriented parallel and perpendicular to the beam direction. Results from the passivated Al(Cu) lines show that with decreasing linewidth, the magnitude of the principal stress components become higher until the line aspect ratio approaching one, then decreased. This behavior is consistent with theoretical predictions by analytical methods and finite element analyses. The stress behavior of the oxide passivation has also been deduced and its magnitude depended on the oxide morphology at the sidewall of the lines. Our result indicates a high level of stress in the sidewall which may cause crack formation during thermal cycling.

Record low-threshold index-guided InGaAs/GaAlAs vertical-cavity surface-emitting laser with a native oxide confinement structure

An index-guided InGaAs/GaAlAs vertical-cavity surface-emitting laser with a native oxide confinement structure has been proposed and fabricated. A record threshold current of 70 µA was achieved with a 5 µm-diameter core device. The proposed structure provides strong electrical and optical confinements. Also a reduction in nonradiative recombination and an improvement in the thermal resistance can be expected.