Depressed index cladding graded barrier separate confinement single quantum well heterostructure laser

Abstract
In this letter, we present data for a novel depressed index cladding laser structure which provides reduced perpendicular far-field divergence angle with acceptable low-threshold current densities. Narrow perpendicular divergence angles of 27° full width at half maximum for a nearly perfect Gaussian beam shape have been measured, with a corresponding near-field spot size of 1.30 μm. Threshold current densities of 309 A/cm2 are observed for 150 μm stripewidth, 780 μm long devices with 0.80 μm transverse spot sizes. Pulsed output powers for unmounted devices are greater than 0.9 W/uncoated facet.