Ridge waveguide distributed-feedback laser diode with a depressed-index cladding layer
AssigneeEastman Kodak Company
InventorKeith B. Kahen
Life of this patent
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Abstract
A ridge waveguide distributed feedback semiconductor laser diode having a depressed-index cladding layer formed on a graded lower cladding layer.
Claims8
A ridge waveguide distributed-feedback semiconductor laser diode comprising;
- (a) a semiconductor substrate of a first conductivity type;
- (b) a lower cladding layer of such first conductivity type deposited on the semiconductor substrate;
- (c) a depressed-index cladding layer of such first conductivity type formed on the lower cladding layer;
- (d) a spacer layer of such first conductivity type deposited on the depressed-index cladding layer;
- (e) a semiconductor active layer formed on the spacer layer;
- (f) a barrier layer of a second conductivity type deposited on the semiconductor active layer;
- (g) a grating layer of such second conductivity type deposited on the barrier layer;
- (h) an upper cladding layer of such second conductivity type deposited on the grating layer;
- (i) a capping layer of such second conductivity type formed on the upper cladding layer;
- (j) a rib structure etched into the capping and upper cladding layers so as to provide lateral guiding;
- and
- (k) electrically conductive layers formed on the substrate and capping layers.
The ridge waveguide distributed-feedback semiconductor laser diode of claim I in which the conductivity of the substrate is either n- or p-type.
The ridge waveguide distributed-feedback semiconductor laser diode of claim I in which the capping layer is n-type and zinc is diffused into the capping and upper cladding layers.
The ridge waveguide distributed-feedback semiconductor laser diode of claim I in which the semiconductor material system is AlGaAs.
Dependencies are inferred from the claim text.