A novel technology for formation of a narrow active layer in buried heterostructure lasers by single-step MOCVD

A new technology of fabricating a buried heterostructure laser with a narrow active layer in a single-step MOCVD process other than the conventional two-step process is proposed. The technology is based on the separate growth on the undercut ridge. The anisotropic growth has been found to be very useful for formation of a very narrow active region in a self-aligned manner. The novel RBH laser implemented by the single-step MOCVD process has been proposed. The RBH laser has exhibited CW lasing oscillation with a threshold current as low as 30 mA at room temperature and with the circular beam spot.