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AssigneeBell Telephone Laboratories, Incorporated
InventorsRobert L. Hartman, Marc Ilegems, Louis A. Koszi, Wilfried R. Wagner
Estimating the term…
A buried double heterostructure laser device isdescribed. A wafer of double heterostructure material is formed into narrow mesa stripes. A native oxide coating is formed on the side walls of the mesa. Semiconductor material having an index of refraction which is closely matched to the index of the active region is deposited over the mesa structure. High resistivity polycrystalline material forms on the native oxide and monocrystalline material forms on the top of the mesa. Vertical carrier and optical confinement is achieved by the higher bandgap cladding layers of the double heterostructure configuration. The native oxide acts as an electrical insulator to confine pumping current to the mesa. The closely matched polycrystalline material confines light parallel to the junction plane and prevents excitation of higher order transverse modes. Devices have been fabricated which exhibit cw threshold currents at room temperature as low as 55 mA.
A double heterostructure laser device including a multilayered structure comprising a semiconductor body of one conductivity type, a wide bandgap first cladding layer of the same conductivity type disposed on a major surface of said body, a narrower bandgap active region disposed on said first layer, and a wide bandgap second cladding layer of opposite conductivity type disposed on said active region, said active region being capable of emitting stimulated radiation when said cladding layers are forward biased, said multilayered structure having the shape of an elongated mesa which extends parallel to the direction of propagation of said radiation, electrode means for applying said forward bias and means for forming an optical resonator for said radiation CHARACTERIZED IN THAT
A double heterostructure device comprising:
Dependencies are inferred from the claim text.