Distributed feedback (dfb) quantum dot laser structure

Abstract

A distributed feedback (DFB) quantum dot semiconductor laser structure is provided. The DFB quantum dot semi-conductor laser structure includes: a first clad layer formed on a lower electrode; an optical waveguide (WG) formed on the first clad layer; a grating structure layer formed on the optical WG and including a plurality of periodically disposed gratings; a first separate confinement hetero (SCH) layer formed on the grating structure layer; an active layer formed on the first SCH layer and including at least a quantum dot; a second SCH layer formed on the active layer; a second clad layer formed on the second SCH layer; an ohmic layer formed on the second clad layer; and an upper electrode formed on the ohmic layer. Accordingly, an optical WG is disposed on the opposite side of the active layer from the grating structure layer, thereby increasing single optical mode efficiency. And, an asymmetric multi-electrode structure is used for applying current, thereby maximizing purity and efficiency of the single mode semiconductor laser structure.