Buried heterostructure laser with quaternary current blocking layer
AssigneeNortel Networks Limited
InventorsDouglas Gordon Knight, Chunmeng Wu
Life of this patent
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Abstract
The lateral confinement region provided on both sides of an active region stripe of a buried heterostructure laser is formed of an alloy of InGaAsP instead of the conventional Fe doped InP material. This results in much improved regrowth morphology while still achieving good current and light blocking properties.
Claims23
A buried heterostructure semiconductor laser in which an active region is contained in a stripe delineated on opposite sidewalls by a current and light blocking layer wherein the blocking layer is a doped InGaAsP alloy, the degree of doping and type of dopant rendering the blocking layer semi-insulating with a bandgap wavelength less than the lasing wavelength of the laser.
A buried heterostructure semiconductor laser comprising a substrate of heavily n-doped InP, an n-doped buffer layer on the substrate, a stripe etched into the buffer layer and containing in addition to an uppermost portion of the buffer layer, lower GRINSCH layers of InGaAsP alloy on the buffer layer, an active region of InGaAsP on the lower GRINSCH layers, upper GRINSCH layers on the active region and a p-doped InP cap layer on the upper GRINSCH layers, the stripe having opposite sidewalls delineated by a current and light blocking doped InGaAsP alloy layer, the degree of doping and type of dopant rendering the blocking layer semi-insulating with a bandgap wavelength less than the lasing wavelength of the laser, and a layer of InP overlying the stripe and the blocking layer.
Dependencies are inferred from the claim text.