(Al,Ga) As Double-Heterostructure Lasers: Comparison of Devices Fabricated with Deep and Shallow Proton Bombardment

Injection laser light sources must possess improved optical output linearity to be useful in many applications. This paper explores experimentally the optimal linearity and current-threshold distributions of (Al, Ga) As proton-bombardment-delineated, stripe-geometry, double-heterostructure lasers as a function of stripe width and contrasts the cases in which the protons do and do not penetrate the active volume. For comparison, we evaluate the corresponding theoretically expected threshold currents from a new theory of current-crowded carrier confinement. We demonstrate that shallow proton bombardment with adequately narrow stripes can result in satisfactory optical linearity without the threshold penalty that has been associated with narrow-stripe-width devices in which the protons penetrate the active volume.